Merge flask framework and other stuff from master

20 files changed, 7808 insertions, 0 deletions

diff --git a/python/flask/__init__.py b/python/flask/__init__.py
new file mode 100644
index 0000000..59f0fff
--- /dev/null
+++ b/python/flask/__init__.py
@@ -0,0 +1,49 @@
+# -*- coding: utf-8 -*-
+"""
+    flask
+    ~~~~~
+
+    A microframework based on Werkzeug.  It's extensively documented
+    and follows best practice patterns.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+__version__ = '1.0.3'
+
+# utilities we import from Werkzeug and Jinja2 that are unused
+# in the module but are exported as public interface.
+from werkzeug.exceptions import abort
+from werkzeug.utils import redirect
+from jinja2 import Markup, escape
+
+from .app import Flask, Request, Response
+from .config import Config
+from .helpers import url_for, flash, send_file, send_from_directory, \
+     get_flashed_messages, get_template_attribute, make_response, safe_join, \
+     stream_with_context
+from .globals import current_app, g, request, session, _request_ctx_stack, \
+     _app_ctx_stack
+from .ctx import has_request_context, has_app_context, \
+     after_this_request, copy_current_request_context
+from .blueprints import Blueprint
+from .templating import render_template, render_template_string
+
+# the signals
+from .signals import signals_available, template_rendered, request_started, \
+     request_finished, got_request_exception, request_tearing_down, \
+     appcontext_tearing_down, appcontext_pushed, \
+     appcontext_popped, message_flashed, before_render_template
+
+# We're not exposing the actual json module but a convenient wrapper around
+# it.
+from . import json
+
+# This was the only thing that Flask used to export at one point and it had
+# a more generic name.
+jsonify = json.jsonify
+
+# backwards compat, goes away in 1.0
+from .sessions import SecureCookieSession as Session
+json_available = True
diff --git a/python/flask/__main__.py b/python/flask/__main__.py
new file mode 100644
index 0000000..4aee654
--- /dev/null
+++ b/python/flask/__main__.py
@@ -0,0 +1,14 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.__main__
+    ~~~~~~~~~~~~~~
+
+    Alias for flask.run for the command line.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+if __name__ == '__main__':
+    from .cli import main
+    main(as_module=True)
diff --git a/python/flask/_compat.py b/python/flask/_compat.py
new file mode 100644
index 0000000..dfbaae9
--- /dev/null
+++ b/python/flask/_compat.py
@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+"""
+    flask._compat
+    ~~~~~~~~~~~~~
+
+    Some py2/py3 compatibility support based on a stripped down
+    version of six so we don't have to depend on a specific version
+    of it.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import sys
+
+PY2 = sys.version_info[0] == 2
+_identity = lambda x: x
+
+
+if not PY2:
+    text_type = str
+    string_types = (str,)
+    integer_types = (int,)
+
+    iterkeys = lambda d: iter(d.keys())
+    itervalues = lambda d: iter(d.values())
+    iteritems = lambda d: iter(d.items())
+
+    from inspect import getfullargspec as getargspec
+    from io import StringIO
+    import collections.abc as collections_abc
+
+    def reraise(tp, value, tb=None):
+        if value.__traceback__ is not tb:
+            raise value.with_traceback(tb)
+        raise value
+
+    implements_to_string = _identity
+
+else:
+    text_type = unicode
+    string_types = (str, unicode)
+    integer_types = (int, long)
+
+    iterkeys = lambda d: d.iterkeys()
+    itervalues = lambda d: d.itervalues()
+    iteritems = lambda d: d.iteritems()
+
+    from inspect import getargspec
+    from cStringIO import StringIO
+    import collections as collections_abc
+
+    exec('def reraise(tp, value, tb=None):\n raise tp, value, tb')
+
+    def implements_to_string(cls):
+        cls.__unicode__ = cls.__str__
+        cls.__str__ = lambda x: x.__unicode__().encode('utf-8')
+        return cls
+
+
+def with_metaclass(meta, *bases):
+    """Create a base class with a metaclass."""
+    # This requires a bit of explanation: the basic idea is to make a
+    # dummy metaclass for one level of class instantiation that replaces
+    # itself with the actual metaclass.
+    class metaclass(type):
+        def __new__(cls, name, this_bases, d):
+            return meta(name, bases, d)
+    return type.__new__(metaclass, 'temporary_class', (), {})
+
+
+# Certain versions of pypy have a bug where clearing the exception stack
+# breaks the __exit__ function in a very peculiar way.  The second level of
+# exception blocks is necessary because pypy seems to forget to check if an
+# exception happened until the next bytecode instruction?
+#
+# Relevant PyPy bugfix commit:
+# https://bitbucket.org/pypy/pypy/commits/77ecf91c635a287e88e60d8ddb0f4e9df4003301
+# According to ronan on #pypy IRC, it is released in PyPy2 2.3 and later
+# versions.
+#
+# Ubuntu 14.04 has PyPy 2.2.1, which does exhibit this bug.
+BROKEN_PYPY_CTXMGR_EXIT = False
+if hasattr(sys, 'pypy_version_info'):
+    class _Mgr(object):
+        def __enter__(self):
+            return self
+        def __exit__(self, *args):
+            if hasattr(sys, 'exc_clear'):
+                # Python 3 (PyPy3) doesn't have exc_clear
+                sys.exc_clear()
+    try:
+        try:
+            with _Mgr():
+                raise AssertionError()
+        except:
+            raise
+    except TypeError:
+        BROKEN_PYPY_CTXMGR_EXIT = True
+    except AssertionError:
+        pass
diff --git a/python/flask/app.py b/python/flask/app.py
new file mode 100644
index 0000000..c570a95
--- /dev/null
+++ b/python/flask/app.py
@@ -0,0 +1,2334 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.app
+    ~~~~~~~~~
+
+    This module implements the central WSGI application object.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import os
+import sys
+import warnings
+from datetime import timedelta
+from functools import update_wrapper
+from itertools import chain
+from threading import Lock
+
+from werkzeug.datastructures import Headers, ImmutableDict
+from werkzeug.exceptions import BadRequest, BadRequestKeyError, HTTPException, \
+    InternalServerError, MethodNotAllowed, default_exceptions
+from werkzeug.routing import BuildError, Map, RequestRedirect, \
+    RoutingException, Rule
+
+from . import cli, json
+from ._compat import integer_types, reraise, string_types, text_type
+from .config import Config, ConfigAttribute
+from .ctx import AppContext, RequestContext, _AppCtxGlobals
+from .globals import _request_ctx_stack, g, request, session
+from .helpers import (
+    _PackageBoundObject,
+    _endpoint_from_view_func, find_package, get_env, get_debug_flag,
+    get_flashed_messages, locked_cached_property, url_for, get_load_dotenv
+)
+from .logging import create_logger
+from .sessions import SecureCookieSessionInterface
+from .signals import appcontext_tearing_down, got_request_exception, \
+    request_finished, request_started, request_tearing_down
+from .templating import DispatchingJinjaLoader, Environment, \
+    _default_template_ctx_processor
+from .wrappers import Request, Response
+
+# a singleton sentinel value for parameter defaults
+_sentinel = object()
+
+
+def _make_timedelta(value):
+    if not isinstance(value, timedelta):
+        return timedelta(seconds=value)
+    return value
+
+
+def setupmethod(f):
+    """Wraps a method so that it performs a check in debug mode if the
+    first request was already handled.
+    """
+    def wrapper_func(self, *args, **kwargs):
+        if self.debug and self._got_first_request:
+            raise AssertionError('A setup function was called after the '
+                'first request was handled.  This usually indicates a bug '
+                'in the application where a module was not imported '
+                'and decorators or other functionality was called too late.\n'
+                'To fix this make sure to import all your view modules, '
+                'database models and everything related at a central place '
+                'before the application starts serving requests.')
+        return f(self, *args, **kwargs)
+    return update_wrapper(wrapper_func, f)
+
+
+class Flask(_PackageBoundObject):
+    """The flask object implements a WSGI application and acts as the central
+    object.  It is passed the name of the module or package of the
+    application.  Once it is created it will act as a central registry for
+    the view functions, the URL rules, template configuration and much more.
+
+    The name of the package is used to resolve resources from inside the
+    package or the folder the module is contained in depending on if the
+    package parameter resolves to an actual python package (a folder with
+    an :file:`__init__.py` file inside) or a standard module (just a ``.py`` file).
+
+    For more information about resource loading, see :func:`open_resource`.
+
+    Usually you create a :class:`Flask` instance in your main module or
+    in the :file:`__init__.py` file of your package like this::
+
+        from flask import Flask
+        app = Flask(__name__)
+
+    .. admonition:: About the First Parameter
+
+        The idea of the first parameter is to give Flask an idea of what
+        belongs to your application.  This name is used to find resources
+        on the filesystem, can be used by extensions to improve debugging
+        information and a lot more.
+
+        So it's important what you provide there.  If you are using a single
+        module, `__name__` is always the correct value.  If you however are
+        using a package, it's usually recommended to hardcode the name of
+        your package there.
+
+        For example if your application is defined in :file:`yourapplication/app.py`
+        you should create it with one of the two versions below::
+
+            app = Flask('yourapplication')
+            app = Flask(__name__.split('.')[0])
+
+        Why is that?  The application will work even with `__name__`, thanks
+        to how resources are looked up.  However it will make debugging more
+        painful.  Certain extensions can make assumptions based on the
+        import name of your application.  For example the Flask-SQLAlchemy
+        extension will look for the code in your application that triggered
+        an SQL query in debug mode.  If the import name is not properly set
+        up, that debugging information is lost.  (For example it would only
+        pick up SQL queries in `yourapplication.app` and not
+        `yourapplication.views.frontend`)
+
+    .. versionadded:: 0.7
+       The `static_url_path`, `static_folder`, and `template_folder`
+       parameters were added.
+
+    .. versionadded:: 0.8
+       The `instance_path` and `instance_relative_config` parameters were
+       added.
+
+    .. versionadded:: 0.11
+       The `root_path` parameter was added.
+
+    .. versionadded:: 1.0
+       The ``host_matching`` and ``static_host`` parameters were added.
+
+    .. versionadded:: 1.0
+       The ``subdomain_matching`` parameter was added. Subdomain
+       matching needs to be enabled manually now. Setting
+       :data:`SERVER_NAME` does not implicitly enable it.
+
+    :param import_name: the name of the application package
+    :param static_url_path: can be used to specify a different path for the
+                            static files on the web.  Defaults to the name
+                            of the `static_folder` folder.
+    :param static_folder: the folder with static files that should be served
+                          at `static_url_path`.  Defaults to the ``'static'``
+                          folder in the root path of the application.
+    :param static_host: the host to use when adding the static route.
+        Defaults to None. Required when using ``host_matching=True``
+        with a ``static_folder`` configured.
+    :param host_matching: set ``url_map.host_matching`` attribute.
+        Defaults to False.
+    :param subdomain_matching: consider the subdomain relative to
+        :data:`SERVER_NAME` when matching routes. Defaults to False.
+    :param template_folder: the folder that contains the templates that should
+                            be used by the application.  Defaults to
+                            ``'templates'`` folder in the root path of the
+                            application.
+    :param instance_path: An alternative instance path for the application.
+                          By default the folder ``'instance'`` next to the
+                          package or module is assumed to be the instance
+                          path.
+    :param instance_relative_config: if set to ``True`` relative filenames
+                                     for loading the config are assumed to
+                                     be relative to the instance path instead
+                                     of the application root.
+    :param root_path: Flask by default will automatically calculate the path
+                      to the root of the application.  In certain situations
+                      this cannot be achieved (for instance if the package
+                      is a Python 3 namespace package) and needs to be
+                      manually defined.
+    """
+
+    #: The class that is used for request objects.  See :class:`~flask.Request`
+    #: for more information.
+    request_class = Request
+
+    #: The class that is used for response objects.  See
+    #: :class:`~flask.Response` for more information.
+    response_class = Response
+
+    #: The class that is used for the Jinja environment.
+    #:
+    #: .. versionadded:: 0.11
+    jinja_environment = Environment
+
+    #: The class that is used for the :data:`~flask.g` instance.
+    #:
+    #: Example use cases for a custom class:
+    #:
+    #: 1. Store arbitrary attributes on flask.g.
+    #: 2. Add a property for lazy per-request database connectors.
+    #: 3. Return None instead of AttributeError on unexpected attributes.
+    #: 4. Raise exception if an unexpected attr is set, a "controlled" flask.g.
+    #:
+    #: In Flask 0.9 this property was called `request_globals_class` but it
+    #: was changed in 0.10 to :attr:`app_ctx_globals_class` because the
+    #: flask.g object is now application context scoped.
+    #:
+    #: .. versionadded:: 0.10
+    app_ctx_globals_class = _AppCtxGlobals
+
+    #: The class that is used for the ``config`` attribute of this app.
+    #: Defaults to :class:`~flask.Config`.
+    #:
+    #: Example use cases for a custom class:
+    #:
+    #: 1. Default values for certain config options.
+    #: 2. Access to config values through attributes in addition to keys.
+    #:
+    #: .. versionadded:: 0.11
+    config_class = Config
+
+    #: The testing flag.  Set this to ``True`` to enable the test mode of
+    #: Flask extensions (and in the future probably also Flask itself).
+    #: For example this might activate test helpers that have an
+    #: additional runtime cost which should not be enabled by default.
+    #:
+    #: If this is enabled and PROPAGATE_EXCEPTIONS is not changed from the
+    #: default it's implicitly enabled.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``TESTING`` configuration key.  Defaults to ``False``.
+    testing = ConfigAttribute('TESTING')
+
+    #: If a secret key is set, cryptographic components can use this to
+    #: sign cookies and other things. Set this to a complex random value
+    #: when you want to use the secure cookie for instance.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: :data:`SECRET_KEY` configuration key. Defaults to ``None``.
+    secret_key = ConfigAttribute('SECRET_KEY')
+
+    #: The secure cookie uses this for the name of the session cookie.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``SESSION_COOKIE_NAME`` configuration key.  Defaults to ``'session'``
+    session_cookie_name = ConfigAttribute('SESSION_COOKIE_NAME')
+
+    #: A :class:`~datetime.timedelta` which is used to set the expiration
+    #: date of a permanent session.  The default is 31 days which makes a
+    #: permanent session survive for roughly one month.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``PERMANENT_SESSION_LIFETIME`` configuration key.  Defaults to
+    #: ``timedelta(days=31)``
+    permanent_session_lifetime = ConfigAttribute('PERMANENT_SESSION_LIFETIME',
+        get_converter=_make_timedelta)
+
+    #: A :class:`~datetime.timedelta` which is used as default cache_timeout
+    #: for the :func:`send_file` functions. The default is 12 hours.
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``SEND_FILE_MAX_AGE_DEFAULT`` configuration key. This configuration
+    #: variable can also be set with an integer value used as seconds.
+    #: Defaults to ``timedelta(hours=12)``
+    send_file_max_age_default = ConfigAttribute('SEND_FILE_MAX_AGE_DEFAULT',
+        get_converter=_make_timedelta)
+
+    #: Enable this if you want to use the X-Sendfile feature.  Keep in
+    #: mind that the server has to support this.  This only affects files
+    #: sent with the :func:`send_file` method.
+    #:
+    #: .. versionadded:: 0.2
+    #:
+    #: This attribute can also be configured from the config with the
+    #: ``USE_X_SENDFILE`` configuration key.  Defaults to ``False``.
+    use_x_sendfile = ConfigAttribute('USE_X_SENDFILE')
+
+    #: The JSON encoder class to use.  Defaults to :class:`~flask.json.JSONEncoder`.
+    #:
+    #: .. versionadded:: 0.10
+    json_encoder = json.JSONEncoder
+
+    #: The JSON decoder class to use.  Defaults to :class:`~flask.json.JSONDecoder`.
+    #:
+    #: .. versionadded:: 0.10
+    json_decoder = json.JSONDecoder
+
+    #: Options that are passed directly to the Jinja2 environment.
+    jinja_options = ImmutableDict(
+        extensions=['jinja2.ext.autoescape', 'jinja2.ext.with_']
+    )
+
+    #: Default configuration parameters.
+    default_config = ImmutableDict({
+        'ENV':                                  None,
+        'DEBUG':                                None,
+        'TESTING':                              False,
+        'PROPAGATE_EXCEPTIONS':                 None,
+        'PRESERVE_CONTEXT_ON_EXCEPTION':        None,
+        'SECRET_KEY':                           None,
+        'PERMANENT_SESSION_LIFETIME':           timedelta(days=31),
+        'USE_X_SENDFILE':                       False,
+        'SERVER_NAME':                          None,
+        'APPLICATION_ROOT':                     '/',
+        'SESSION_COOKIE_NAME':                  'session',
+        'SESSION_COOKIE_DOMAIN':                None,
+        'SESSION_COOKIE_PATH':                  None,
+        'SESSION_COOKIE_HTTPONLY':              True,
+        'SESSION_COOKIE_SECURE':                False,
+        'SESSION_COOKIE_SAMESITE':              None,
+        'SESSION_REFRESH_EACH_REQUEST':         True,
+        'MAX_CONTENT_LENGTH':                   None,
+        'SEND_FILE_MAX_AGE_DEFAULT':            timedelta(hours=12),
+        'TRAP_BAD_REQUEST_ERRORS':              None,
+        'TRAP_HTTP_EXCEPTIONS':                 False,
+        'EXPLAIN_TEMPLATE_LOADING':             False,
+        'PREFERRED_URL_SCHEME':                 'http',
+        'JSON_AS_ASCII':                        True,
+        'JSON_SORT_KEYS':                       True,
+        'JSONIFY_PRETTYPRINT_REGULAR':          False,
+        'JSONIFY_MIMETYPE':                     'application/json',
+        'TEMPLATES_AUTO_RELOAD':                None,
+        'MAX_COOKIE_SIZE': 4093,
+    })
+
+    #: The rule object to use for URL rules created.  This is used by
+    #: :meth:`add_url_rule`.  Defaults to :class:`werkzeug.routing.Rule`.
+    #:
+    #: .. versionadded:: 0.7
+    url_rule_class = Rule
+
+    #: the test client that is used with when `test_client` is used.
+    #:
+    #: .. versionadded:: 0.7
+    test_client_class = None
+
+    #: The :class:`~click.testing.CliRunner` subclass, by default
+    #: :class:`~flask.testing.FlaskCliRunner` that is used by
+    #: :meth:`test_cli_runner`. Its ``__init__`` method should take a
+    #: Flask app object as the first argument.
+    #:
+    #: .. versionadded:: 1.0
+    test_cli_runner_class = None
+
+    #: the session interface to use.  By default an instance of
+    #: :class:`~flask.sessions.SecureCookieSessionInterface` is used here.
+    #:
+    #: .. versionadded:: 0.8
+    session_interface = SecureCookieSessionInterface()
+
+    # TODO remove the next three attrs when Sphinx :inherited-members: works
+    # https://github.com/sphinx-doc/sphinx/issues/741
+
+    #: The name of the package or module that this app belongs to. Do not
+    #: change this once it is set by the constructor.
+    import_name = None
+
+    #: Location of the template files to be added to the template lookup.
+    #: ``None`` if templates should not be added.
+    template_folder = None
+
+    #: Absolute path to the package on the filesystem. Used to look up
+    #: resources contained in the package.
+    root_path = None
+
+    def __init__(
+        self,
+        import_name,
+        static_url_path=None,
+        static_folder='static',
+        static_host=None,
+        host_matching=False,
+        subdomain_matching=False,
+        template_folder='templates',
+        instance_path=None,
+        instance_relative_config=False,
+        root_path=None
+    ):
+        _PackageBoundObject.__init__(
+            self,
+            import_name,
+            template_folder=template_folder,
+            root_path=root_path
+        )
+
+        if static_url_path is not None:
+            self.static_url_path = static_url_path
+
+        if static_folder is not None:
+            self.static_folder = static_folder
+
+        if instance_path is None:
+            instance_path = self.auto_find_instance_path()
+        elif not os.path.isabs(instance_path):
+            raise ValueError(
+                'If an instance path is provided it must be absolute.'
+                ' A relative path was given instead.'
+            )
+
+        #: Holds the path to the instance folder.
+        #:
+        #: .. versionadded:: 0.8
+        self.instance_path = instance_path
+
+        #: The configuration dictionary as :class:`Config`.  This behaves
+        #: exactly like a regular dictionary but supports additional methods
+        #: to load a config from files.
+        self.config = self.make_config(instance_relative_config)
+
+        #: A dictionary of all view functions registered.  The keys will
+        #: be function names which are also used to generate URLs and
+        #: the values are the function objects themselves.
+        #: To register a view function, use the :meth:`route` decorator.
+        self.view_functions = {}
+
+        #: A dictionary of all registered error handlers.  The key is ``None``
+        #: for error handlers active on the application, otherwise the key is
+        #: the name of the blueprint.  Each key points to another dictionary
+        #: where the key is the status code of the http exception.  The
+        #: special key ``None`` points to a list of tuples where the first item
+        #: is the class for the instance check and the second the error handler
+        #: function.
+        #:
+        #: To register an error handler, use the :meth:`errorhandler`
+        #: decorator.
+        self.error_handler_spec = {}
+
+        #: A list of functions that are called when :meth:`url_for` raises a
+        #: :exc:`~werkzeug.routing.BuildError`.  Each function registered here
+        #: is called with `error`, `endpoint` and `values`.  If a function
+        #: returns ``None`` or raises a :exc:`BuildError` the next function is
+        #: tried.
+        #:
+        #: .. versionadded:: 0.9
+        self.url_build_error_handlers = []
+
+        #: A dictionary with lists of functions that will be called at the
+        #: beginning of each request. The key of the dictionary is the name of
+        #: the blueprint this function is active for, or ``None`` for all
+        #: requests. To register a function, use the :meth:`before_request`
+        #: decorator.
+        self.before_request_funcs = {}
+
+        #: A list of functions that will be called at the beginning of the
+        #: first request to this instance. To register a function, use the
+        #: :meth:`before_first_request` decorator.
+        #:
+        #: .. versionadded:: 0.8
+        self.before_first_request_funcs = []
+
+        #: A dictionary with lists of functions that should be called after
+        #: each request.  The key of the dictionary is the name of the blueprint
+        #: this function is active for, ``None`` for all requests.  This can for
+        #: example be used to close database connections. To register a function
+        #: here, use the :meth:`after_request` decorator.
+        self.after_request_funcs = {}
+
+        #: A dictionary with lists of functions that are called after
+        #: each request, even if an exception has occurred. The key of the
+        #: dictionary is the name of the blueprint this function is active for,
+        #: ``None`` for all requests. These functions are not allowed to modify
+        #: the request, and their return values are ignored. If an exception
+        #: occurred while processing the request, it gets passed to each
+        #: teardown_request function. To register a function here, use the
+        #: :meth:`teardown_request` decorator.
+        #:
+        #: .. versionadded:: 0.7
+        self.teardown_request_funcs = {}
+
+        #: A list of functions that are called when the application context
+        #: is destroyed.  Since the application context is also torn down
+        #: if the request ends this is the place to store code that disconnects
+        #: from databases.
+        #:
+        #: .. versionadded:: 0.9
+        self.teardown_appcontext_funcs = []
+
+        #: A dictionary with lists of functions that are called before the
+        #: :attr:`before_request_funcs` functions. The key of the dictionary is
+        #: the name of the blueprint this function is active for, or ``None``
+        #: for all requests. To register a function, use
+        #: :meth:`url_value_preprocessor`.
+        #:
+        #: .. versionadded:: 0.7
+        self.url_value_preprocessors = {}
+
+        #: A dictionary with lists of functions that can be used as URL value
+        #: preprocessors.  The key ``None`` here is used for application wide
+        #: callbacks, otherwise the key is the name of the blueprint.
+        #: Each of these functions has the chance to modify the dictionary
+        #: of URL values before they are used as the keyword arguments of the
+        #: view function.  For each function registered this one should also
+        #: provide a :meth:`url_defaults` function that adds the parameters
+        #: automatically again that were removed that way.
+        #:
+        #: .. versionadded:: 0.7
+        self.url_default_functions = {}
+
+        #: A dictionary with list of functions that are called without argument
+        #: to populate the template context.  The key of the dictionary is the
+        #: name of the blueprint this function is active for, ``None`` for all
+        #: requests.  Each returns a dictionary that the template context is
+        #: updated with.  To register a function here, use the
+        #: :meth:`context_processor` decorator.
+        self.template_context_processors = {
+            None: [_default_template_ctx_processor]
+        }
+
+        #: A list of shell context processor functions that should be run
+        #: when a shell context is created.
+        #:
+        #: .. versionadded:: 0.11
+        self.shell_context_processors = []
+
+        #: all the attached blueprints in a dictionary by name.  Blueprints
+        #: can be attached multiple times so this dictionary does not tell
+        #: you how often they got attached.
+        #:
+        #: .. versionadded:: 0.7
+        self.blueprints = {}
+        self._blueprint_order = []
+
+        #: a place where extensions can store application specific state.  For
+        #: example this is where an extension could store database engines and
+        #: similar things.  For backwards compatibility extensions should register
+        #: themselves like this::
+        #:
+        #:      if not hasattr(app, 'extensions'):
+        #:          app.extensions = {}
+        #:      app.extensions['extensionname'] = SomeObject()
+        #:
+        #: The key must match the name of the extension module. For example in
+        #: case of a "Flask-Foo" extension in `flask_foo`, the key would be
+        #: ``'foo'``.
+        #:
+        #: .. versionadded:: 0.7
+        self.extensions = {}
+
+        #: The :class:`~werkzeug.routing.Map` for this instance.  You can use
+        #: this to change the routing converters after the class was created
+        #: but before any routes are connected.  Example::
+        #:
+        #:    from werkzeug.routing import BaseConverter
+        #:
+        #:    class ListConverter(BaseConverter):
+        #:        def to_python(self, value):
+        #:            return value.split(',')
+        #:        def to_url(self, values):
+        #:            return ','.join(super(ListConverter, self).to_url(value)
+        #:                            for value in values)
+        #:
+        #:    app = Flask(__name__)
+        #:    app.url_map.converters['list'] = ListConverter
+        self.url_map = Map()
+
+        self.url_map.host_matching = host_matching
+        self.subdomain_matching = subdomain_matching
+
+        # tracks internally if the application already handled at least one
+        # request.
+        self._got_first_request = False
+        self._before_request_lock = Lock()
+
+        # Add a static route using the provided static_url_path, static_host,
+        # and static_folder if there is a configured static_folder.
+        # Note we do this without checking if static_folder exists.
+        # For one, it might be created while the server is running (e.g. during
+        # development). Also, Google App Engine stores static files somewhere
+        if self.has_static_folder:
+            assert bool(static_host) == host_matching, 'Invalid static_host/host_matching combination'
+            self.add_url_rule(
+                self.static_url_path + '/<path:filename>',
+                endpoint='static',
+                host=static_host,
+                view_func=self.send_static_file
+            )
+
+        #: The click command line context for this application.  Commands
+        #: registered here show up in the :command:`flask` command once the
+        #: application has been discovered.  The default commands are
+        #: provided by Flask itself and can be overridden.
+        #:
+        #: This is an instance of a :class:`click.Group` object.
+        self.cli = cli.AppGroup(self.name)
+
+    @locked_cached_property
+    def name(self):
+        """The name of the application.  This is usually the import name
+        with the difference that it's guessed from the run file if the
+        import name is main.  This name is used as a display name when
+        Flask needs the name of the application.  It can be set and overridden
+        to change the value.
+
+        .. versionadded:: 0.8
+        """
+        if self.import_name == '__main__':
+            fn = getattr(sys.modules['__main__'], '__file__', None)
+            if fn is None:
+                return '__main__'
+            return os.path.splitext(os.path.basename(fn))[0]
+        return self.import_name
+
+    @property
+    def propagate_exceptions(self):
+        """Returns the value of the ``PROPAGATE_EXCEPTIONS`` configuration
+        value in case it's set, otherwise a sensible default is returned.
+
+        .. versionadded:: 0.7
+        """
+        rv = self.config['PROPAGATE_EXCEPTIONS']
+        if rv is not None:
+            return rv
+        return self.testing or self.debug
+
+    @property
+    def preserve_context_on_exception(self):
+        """Returns the value of the ``PRESERVE_CONTEXT_ON_EXCEPTION``
+        configuration value in case it's set, otherwise a sensible default
+        is returned.
+
+        .. versionadded:: 0.7
+        """
+        rv = self.config['PRESERVE_CONTEXT_ON_EXCEPTION']
+        if rv is not None:
+            return rv
+        return self.debug
+
+    @locked_cached_property
+    def logger(self):
+        """The ``'flask.app'`` logger, a standard Python
+        :class:`~logging.Logger`.
+
+        In debug mode, the logger's :attr:`~logging.Logger.level` will be set
+        to :data:`~logging.DEBUG`.
+
+        If there are no handlers configured, a default handler will be added.
+        See :ref:`logging` for more information.
+
+        .. versionchanged:: 1.0
+            Behavior was simplified. The logger is always named
+            ``flask.app``. The level is only set during configuration, it
+            doesn't check ``app.debug`` each time. Only one format is used,
+            not different ones depending on ``app.debug``. No handlers are
+            removed, and a handler is only added if no handlers are already
+            configured.
+
+        .. versionadded:: 0.3
+        """
+        return create_logger(self)
+
+    @locked_cached_property
+    def jinja_env(self):
+        """The Jinja2 environment used to load templates."""
+        return self.create_jinja_environment()
+
+    @property
+    def got_first_request(self):
+        """This attribute is set to ``True`` if the application started
+        handling the first request.
+
+        .. versionadded:: 0.8
+        """
+        return self._got_first_request
+
+    def make_config(self, instance_relative=False):
+        """Used to create the config attribute by the Flask constructor.
+        The `instance_relative` parameter is passed in from the constructor
+        of Flask (there named `instance_relative_config`) and indicates if
+        the config should be relative to the instance path or the root path
+        of the application.
+
+        .. versionadded:: 0.8
+        """
+        root_path = self.root_path
+        if instance_relative:
+            root_path = self.instance_path
+        defaults = dict(self.default_config)
+        defaults['ENV'] = get_env()
+        defaults['DEBUG'] = get_debug_flag()
+        return self.config_class(root_path, defaults)
+
+    def auto_find_instance_path(self):
+        """Tries to locate the instance path if it was not provided to the
+        constructor of the application class.  It will basically calculate
+        the path to a folder named ``instance`` next to your main file or
+        the package.
+
+        .. versionadded:: 0.8
+        """
+        prefix, package_path = find_package(self.import_name)
+        if prefix is None:
+            return os.path.join(package_path, 'instance')
+        return os.path.join(prefix, 'var', self.name + '-instance')
+
+    def open_instance_resource(self, resource, mode='rb'):
+        """Opens a resource from the application's instance folder
+        (:attr:`instance_path`).  Otherwise works like
+        :meth:`open_resource`.  Instance resources can also be opened for
+        writing.
+
+        :param resource: the name of the resource.  To access resources within
+                         subfolders use forward slashes as separator.
+        :param mode: resource file opening mode, default is 'rb'.
+        """
+        return open(os.path.join(self.instance_path, resource), mode)
+
+    def _get_templates_auto_reload(self):
+        """Reload templates when they are changed. Used by
+        :meth:`create_jinja_environment`.
+
+        This attribute can be configured with :data:`TEMPLATES_AUTO_RELOAD`. If
+        not set, it will be enabled in debug mode.
+
+        .. versionadded:: 1.0
+            This property was added but the underlying config and behavior
+            already existed.
+        """
+        rv = self.config['TEMPLATES_AUTO_RELOAD']
+        return rv if rv is not None else self.debug
+
+    def _set_templates_auto_reload(self, value):
+        self.config['TEMPLATES_AUTO_RELOAD'] = value
+
+    templates_auto_reload = property(
+        _get_templates_auto_reload, _set_templates_auto_reload
+    )
+    del _get_templates_auto_reload, _set_templates_auto_reload
+
+    def create_jinja_environment(self):
+        """Creates the Jinja2 environment based on :attr:`jinja_options`
+        and :meth:`select_jinja_autoescape`.  Since 0.7 this also adds
+        the Jinja2 globals and filters after initialization.  Override
+        this function to customize the behavior.
+
+        .. versionadded:: 0.5
+        .. versionchanged:: 0.11
+           ``Environment.auto_reload`` set in accordance with
+           ``TEMPLATES_AUTO_RELOAD`` configuration option.
+        """
+        options = dict(self.jinja_options)
+
+        if 'autoescape' not in options:
+            options['autoescape'] = self.select_jinja_autoescape
+
+        if 'auto_reload' not in options:
+            options['auto_reload'] = self.templates_auto_reload
+
+        rv = self.jinja_environment(self, **options)
+        rv.globals.update(
+            url_for=url_for,
+            get_flashed_messages=get_flashed_messages,
+            config=self.config,
+            # request, session and g are normally added with the
+            # context processor for efficiency reasons but for imported
+            # templates we also want the proxies in there.
+            request=request,
+            session=session,
+            g=g
+        )
+        rv.filters['tojson'] = json.tojson_filter
+        return rv
+
+    def create_global_jinja_loader(self):
+        """Creates the loader for the Jinja2 environment.  Can be used to
+        override just the loader and keeping the rest unchanged.  It's
+        discouraged to override this function.  Instead one should override
+        the :meth:`jinja_loader` function instead.
+
+        The global loader dispatches between the loaders of the application
+        and the individual blueprints.
+
+        .. versionadded:: 0.7
+        """
+        return DispatchingJinjaLoader(self)
+
+    def select_jinja_autoescape(self, filename):
+        """Returns ``True`` if autoescaping should be active for the given
+        template name. If no template name is given, returns `True`.
+
+        .. versionadded:: 0.5
+        """
+        if filename is None:
+            return True
+        return filename.endswith(('.html', '.htm', '.xml', '.xhtml'))
+
+    def update_template_context(self, context):
+        """Update the template context with some commonly used variables.
+        This injects request, session, config and g into the template
+        context as well as everything template context processors want
+        to inject.  Note that the as of Flask 0.6, the original values
+        in the context will not be overridden if a context processor
+        decides to return a value with the same key.
+
+        :param context: the context as a dictionary that is updated in place
+                        to add extra variables.
+        """
+        funcs = self.template_context_processors[None]
+        reqctx = _request_ctx_stack.top
+        if reqctx is not None:
+            bp = reqctx.request.blueprint
+            if bp is not None and bp in self.template_context_processors:
+                funcs = chain(funcs, self.template_context_processors[bp])
+        orig_ctx = context.copy()
+        for func in funcs:
+            context.update(func())
+        # make sure the original values win.  This makes it possible to
+        # easier add new variables in context processors without breaking
+        # existing views.
+        context.update(orig_ctx)
+
+    def make_shell_context(self):
+        """Returns the shell context for an interactive shell for this
+        application.  This runs all the registered shell context
+        processors.
+
+        .. versionadded:: 0.11
+        """
+        rv = {'app': self, 'g': g}
+        for processor in self.shell_context_processors:
+            rv.update(processor())
+        return rv
+
+    #: What environment the app is running in. Flask and extensions may
+    #: enable behaviors based on the environment, such as enabling debug
+    #: mode. This maps to the :data:`ENV` config key. This is set by the
+    #: :envvar:`FLASK_ENV` environment variable and may not behave as
+    #: expected if set in code.
+    #:
+    #: **Do not enable development when deploying in production.**
+    #:
+    #: Default: ``'production'``
+    env = ConfigAttribute('ENV')
+
+    def _get_debug(self):
+        return self.config['DEBUG']
+
+    def _set_debug(self, value):
+        self.config['DEBUG'] = value
+        self.jinja_env.auto_reload = self.templates_auto_reload
+
+    #: Whether debug mode is enabled. When using ``flask run`` to start
+    #: the development server, an interactive debugger will be shown for
+    #: unhandled exceptions, and the server will be reloaded when code
+    #: changes. This maps to the :data:`DEBUG` config key. This is
+    #: enabled when :attr:`env` is ``'development'`` and is overridden
+    #: by the ``FLASK_DEBUG`` environment variable. It may not behave as
+    #: expected if set in code.
+    #:
+    #: **Do not enable debug mode when deploying in production.**
+    #:
+    #: Default: ``True`` if :attr:`env` is ``'development'``, or
+    #: ``False`` otherwise.
+    debug = property(_get_debug, _set_debug)
+    del _get_debug, _set_debug
+
+    def run(self, host=None, port=None, debug=None,
+            load_dotenv=True, **options):
+        """Runs the application on a local development server.
+
+        Do not use ``run()`` in a production setting. It is not intended to
+        meet security and performance requirements for a production server.
+        Instead, see :ref:`deployment` for WSGI server recommendations.
+
+        If the :attr:`debug` flag is set the server will automatically reload
+        for code changes and show a debugger in case an exception happened.
+
+        If you want to run the application in debug mode, but disable the
+        code execution on the interactive debugger, you can pass
+        ``use_evalex=False`` as parameter.  This will keep the debugger's
+        traceback screen active, but disable code execution.
+
+        It is not recommended to use this function for development with
+        automatic reloading as this is badly supported.  Instead you should
+        be using the :command:`flask` command line script's ``run`` support.
+
+        .. admonition:: Keep in Mind
+
+           Flask will suppress any server error with a generic error page
+           unless it is in debug mode.  As such to enable just the
+           interactive debugger without the code reloading, you have to
+           invoke :meth:`run` with ``debug=True`` and ``use_reloader=False``.
+           Setting ``use_debugger`` to ``True`` without being in debug mode
+           won't catch any exceptions because there won't be any to
+           catch.
+
+        :param host: the hostname to listen on. Set this to ``'0.0.0.0'`` to
+            have the server available externally as well. Defaults to
+            ``'127.0.0.1'`` or the host in the ``SERVER_NAME`` config variable
+            if present.
+        :param port: the port of the webserver. Defaults to ``5000`` or the
+            port defined in the ``SERVER_NAME`` config variable if present.
+        :param debug: if given, enable or disable debug mode. See
+            :attr:`debug`.
+        :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
+            files to set environment variables. Will also change the working
+            directory to the directory containing the first file found.
+        :param options: the options to be forwarded to the underlying Werkzeug
+            server. See :func:`werkzeug.serving.run_simple` for more
+            information.
+
+        .. versionchanged:: 1.0
+            If installed, python-dotenv will be used to load environment
+            variables from :file:`.env` and :file:`.flaskenv` files.
+
+            If set, the :envvar:`FLASK_ENV` and :envvar:`FLASK_DEBUG`
+            environment variables will override :attr:`env` and
+            :attr:`debug`.
+
+            Threaded mode is enabled by default.
+
+        .. versionchanged:: 0.10
+            The default port is now picked from the ``SERVER_NAME``
+            variable.
+        """
+        # Change this into a no-op if the server is invoked from the
+        # command line. Have a look at cli.py for more information.
+        if os.environ.get('FLASK_RUN_FROM_CLI') == 'true':
+            from .debughelpers import explain_ignored_app_run
+            explain_ignored_app_run()
+            return
+
+        if get_load_dotenv(load_dotenv):
+            cli.load_dotenv()
+
+            # if set, let env vars override previous values
+            if 'FLASK_ENV' in os.environ:
+                self.env = get_env()
+                self.debug = get_debug_flag()
+            elif 'FLASK_DEBUG' in os.environ:
+                self.debug = get_debug_flag()
+
+        # debug passed to method overrides all other sources
+        if debug is not None:
+            self.debug = bool(debug)
+
+        _host = '127.0.0.1'
+        _port = 5000
+        server_name = self.config.get('SERVER_NAME')
+        sn_host, sn_port = None, None
+
+        if server_name:
+            sn_host, _, sn_port = server_name.partition(':')
+
+        host = host or sn_host or _host
+        port = int(port or sn_port or _port)
+
+        options.setdefault('use_reloader', self.debug)
+        options.setdefault('use_debugger', self.debug)
+        options.setdefault('threaded', True)
+
+        cli.show_server_banner(self.env, self.debug, self.name, False)
+
+        from werkzeug.serving import run_simple
+
+        try:
+            run_simple(host, port, self, **options)
+        finally:
+            # reset the first request information if the development server
+            # reset normally.  This makes it possible to restart the server
+            # without reloader and that stuff from an interactive shell.
+            self._got_first_request = False
+
+    def test_client(self, use_cookies=True, **kwargs):
+        """Creates a test client for this application.  For information
+        about unit testing head over to :ref:`testing`.
+
+        Note that if you are testing for assertions or exceptions in your
+        application code, you must set ``app.testing = True`` in order for the
+        exceptions to propagate to the test client.  Otherwise, the exception
+        will be handled by the application (not visible to the test client) and
+        the only indication of an AssertionError or other exception will be a
+        500 status code response to the test client.  See the :attr:`testing`
+        attribute.  For example::
+
+            app.testing = True
+            client = app.test_client()
+
+        The test client can be used in a ``with`` block to defer the closing down
+        of the context until the end of the ``with`` block.  This is useful if
+        you want to access the context locals for testing::
+
+            with app.test_client() as c:
+                rv = c.get('/?vodka=42')
+                assert request.args['vodka'] == '42'
+
+        Additionally, you may pass optional keyword arguments that will then
+        be passed to the application's :attr:`test_client_class` constructor.
+        For example::
+
+            from flask.testing import FlaskClient
+
+            class CustomClient(FlaskClient):
+                def __init__(self, *args, **kwargs):
+                    self._authentication = kwargs.pop("authentication")
+                    super(CustomClient,self).__init__( *args, **kwargs)
+
+            app.test_client_class = CustomClient
+            client = app.test_client(authentication='Basic ....')
+
+        See :class:`~flask.testing.FlaskClient` for more information.
+
+        .. versionchanged:: 0.4
+           added support for ``with`` block usage for the client.
+
+        .. versionadded:: 0.7
+           The `use_cookies` parameter was added as well as the ability
+           to override the client to be used by setting the
+           :attr:`test_client_class` attribute.
+
+        .. versionchanged:: 0.11
+           Added `**kwargs` to support passing additional keyword arguments to
+           the constructor of :attr:`test_client_class`.
+        """
+        cls = self.test_client_class
+        if cls is None:
+            from flask.testing import FlaskClient as cls
+        return cls(self, self.response_class, use_cookies=use_cookies, **kwargs)
+
+    def test_cli_runner(self, **kwargs):
+        """Create a CLI runner for testing CLI commands.
+        See :ref:`testing-cli`.
+
+        Returns an instance of :attr:`test_cli_runner_class`, by default
+        :class:`~flask.testing.FlaskCliRunner`. The Flask app object is
+        passed as the first argument.
+
+        .. versionadded:: 1.0
+        """
+        cls = self.test_cli_runner_class
+
+        if cls is None:
+            from flask.testing import FlaskCliRunner as cls
+
+        return cls(self, **kwargs)
+
+    def open_session(self, request):
+        """Creates or opens a new session.  Default implementation stores all
+        session data in a signed cookie.  This requires that the
+        :attr:`secret_key` is set.  Instead of overriding this method
+        we recommend replacing the :class:`session_interface`.
+
+        .. deprecated: 1.0
+            Will be removed in 1.1. Use ``session_interface.open_session``
+            instead.
+
+        :param request: an instance of :attr:`request_class`.
+        """
+
+        warnings.warn(DeprecationWarning(
+            '"open_session" is deprecated and will be removed in 1.1. Use'
+            ' "session_interface.open_session" instead.'
+        ))
+        return self.session_interface.open_session(self, request)
+
+    def save_session(self, session, response):
+        """Saves the session if it needs updates.  For the default
+        implementation, check :meth:`open_session`.  Instead of overriding this
+        method we recommend replacing the :class:`session_interface`.
+
+        .. deprecated: 1.0
+            Will be removed in 1.1. Use ``session_interface.save_session``
+            instead.
+
+        :param session: the session to be saved (a
+                        :class:`~werkzeug.contrib.securecookie.SecureCookie`
+                        object)
+        :param response: an instance of :attr:`response_class`
+        """
+
+        warnings.warn(DeprecationWarning(
+            '"save_session" is deprecated and will be removed in 1.1. Use'
+            ' "session_interface.save_session" instead.'
+        ))
+        return self.session_interface.save_session(self, session, response)
+
+    def make_null_session(self):
+        """Creates a new instance of a missing session.  Instead of overriding
+        this method we recommend replacing the :class:`session_interface`.
+
+        .. deprecated: 1.0
+            Will be removed in 1.1. Use ``session_interface.make_null_session``
+            instead.
+
+        .. versionadded:: 0.7
+        """
+
+        warnings.warn(DeprecationWarning(
+            '"make_null_session" is deprecated and will be removed in 1.1. Use'
+            ' "session_interface.make_null_session" instead.'
+        ))
+        return self.session_interface.make_null_session(self)
+
+    @setupmethod
+    def register_blueprint(self, blueprint, **options):
+        """Register a :class:`~flask.Blueprint` on the application. Keyword
+        arguments passed to this method will override the defaults set on the
+        blueprint.
+
+        Calls the blueprint's :meth:`~flask.Blueprint.register` method after
+        recording the blueprint in the application's :attr:`blueprints`.
+
+        :param blueprint: The blueprint to register.
+        :param url_prefix: Blueprint routes will be prefixed with this.
+        :param subdomain: Blueprint routes will match on this subdomain.
+        :param url_defaults: Blueprint routes will use these default values for
+            view arguments.
+        :param options: Additional keyword arguments are passed to
+            :class:`~flask.blueprints.BlueprintSetupState`. They can be
+            accessed in :meth:`~flask.Blueprint.record` callbacks.
+
+        .. versionadded:: 0.7
+        """
+        first_registration = False
+
+        if blueprint.name in self.blueprints:
+            assert self.blueprints[blueprint.name] is blueprint, (
+                'A name collision occurred between blueprints %r and %r. Both'
+                ' share the same name "%s". Blueprints that are created on the'
+                ' fly need unique names.' % (
+                    blueprint, self.blueprints[blueprint.name], blueprint.name
+                )
+            )
+        else:
+            self.blueprints[blueprint.name] = blueprint
+            self._blueprint_order.append(blueprint)
+            first_registration = True
+
+        blueprint.register(self, options, first_registration)
+
+    def iter_blueprints(self):
+        """Iterates over all blueprints by the order they were registered.
+
+        .. versionadded:: 0.11
+        """
+        return iter(self._blueprint_order)
+
+    @setupmethod
+    def add_url_rule(self, rule, endpoint=None, view_func=None,
+                     provide_automatic_options=None, **options):
+        """Connects a URL rule.  Works exactly like the :meth:`route`
+        decorator.  If a view_func is provided it will be registered with the
+        endpoint.
+
+        Basically this example::
+
+            @app.route('/')
+            def index():
+                pass
+
+        Is equivalent to the following::
+
+            def index():
+                pass
+            app.add_url_rule('/', 'index', index)
+
+        If the view_func is not provided you will need to connect the endpoint
+        to a view function like so::
+
+            app.view_functions['index'] = index
+
+        Internally :meth:`route` invokes :meth:`add_url_rule` so if you want
+        to customize the behavior via subclassing you only need to change
+        this method.
+
+        For more information refer to :ref:`url-route-registrations`.
+
+        .. versionchanged:: 0.2
+           `view_func` parameter added.
+
+        .. versionchanged:: 0.6
+           ``OPTIONS`` is added automatically as method.
+
+        :param rule: the URL rule as string
+        :param endpoint: the endpoint for the registered URL rule.  Flask
+                         itself assumes the name of the view function as
+                         endpoint
+        :param view_func: the function to call when serving a request to the
+                          provided endpoint
+        :param provide_automatic_options: controls whether the ``OPTIONS``
+            method should be added automatically. This can also be controlled
+            by setting the ``view_func.provide_automatic_options = False``
+            before adding the rule.
+        :param options: the options to be forwarded to the underlying
+                        :class:`~werkzeug.routing.Rule` object.  A change
+                        to Werkzeug is handling of method options.  methods
+                        is a list of methods this rule should be limited
+                        to (``GET``, ``POST`` etc.).  By default a rule
+                        just listens for ``GET`` (and implicitly ``HEAD``).
+                        Starting with Flask 0.6, ``OPTIONS`` is implicitly
+                        added and handled by the standard request handling.
+        """
+        if endpoint is None:
+            endpoint = _endpoint_from_view_func(view_func)
+        options['endpoint'] = endpoint
+        methods = options.pop('methods', None)
+
+        # if the methods are not given and the view_func object knows its
+        # methods we can use that instead.  If neither exists, we go with
+        # a tuple of only ``GET`` as default.
+        if methods is None:
+            methods = getattr(view_func, 'methods', None) or ('GET',)
+        if isinstance(methods, string_types):
+            raise TypeError('Allowed methods have to be iterables of strings, '
+                            'for example: @app.route(..., methods=["POST"])')
+        methods = set(item.upper() for item in methods)
+
+        # Methods that should always be added
+        required_methods = set(getattr(view_func, 'required_methods', ()))
+
+        # starting with Flask 0.8 the view_func object can disable and
+        # force-enable the automatic options handling.
+        if provide_automatic_options is None:
+            provide_automatic_options = getattr(view_func,
+                'provide_automatic_options', None)
+
+        if provide_automatic_options is None:
+            if 'OPTIONS' not in methods:
+                provide_automatic_options = True
+                required_methods.add('OPTIONS')
+            else:
+                provide_automatic_options = False
+
+        # Add the required methods now.
+        methods |= required_methods
+
+        rule = self.url_rule_class(rule, methods=methods, **options)
+        rule.provide_automatic_options = provide_automatic_options
+
+        self.url_map.add(rule)
+        if view_func is not None:
+            old_func = self.view_functions.get(endpoint)
+            if old_func is not None and old_func != view_func:
+                raise AssertionError('View function mapping is overwriting an '
+                                     'existing endpoint function: %s' % endpoint)
+            self.view_functions[endpoint] = view_func
+
+    def route(self, rule, **options):
+        """A decorator that is used to register a view function for a
+        given URL rule.  This does the same thing as :meth:`add_url_rule`
+        but is intended for decorator usage::
+
+            @app.route('/')
+            def index():
+                return 'Hello World'
+
+        For more information refer to :ref:`url-route-registrations`.
+
+        :param rule: the URL rule as string
+        :param endpoint: the endpoint for the registered URL rule.  Flask
+                         itself assumes the name of the view function as
+                         endpoint
+        :param options: the options to be forwarded to the underlying
+                        :class:`~werkzeug.routing.Rule` object.  A change
+                        to Werkzeug is handling of method options.  methods
+                        is a list of methods this rule should be limited
+                        to (``GET``, ``POST`` etc.).  By default a rule
+                        just listens for ``GET`` (and implicitly ``HEAD``).
+                        Starting with Flask 0.6, ``OPTIONS`` is implicitly
+                        added and handled by the standard request handling.
+        """
+        def decorator(f):
+            endpoint = options.pop('endpoint', None)
+            self.add_url_rule(rule, endpoint, f, **options)
+            return f
+        return decorator
+
+    @setupmethod
+    def endpoint(self, endpoint):
+        """A decorator to register a function as an endpoint.
+        Example::
+
+            @app.endpoint('example.endpoint')
+            def example():
+                return "example"
+
+        :param endpoint: the name of the endpoint
+        """
+        def decorator(f):
+            self.view_functions[endpoint] = f
+            return f
+        return decorator
+
+    @staticmethod
+    def _get_exc_class_and_code(exc_class_or_code):
+        """Ensure that we register only exceptions as handler keys"""
+        if isinstance(exc_class_or_code, integer_types):
+            exc_class = default_exceptions[exc_class_or_code]
+        else:
+            exc_class = exc_class_or_code
+
+        assert issubclass(exc_class, Exception)
+
+        if issubclass(exc_class, HTTPException):
+            return exc_class, exc_class.code
+        else:
+            return exc_class, None
+
+    @setupmethod
+    def errorhandler(self, code_or_exception):
+        """Register a function to handle errors by code or exception class.
+
+        A decorator that is used to register a function given an
+        error code.  Example::
+
+            @app.errorhandler(404)
+            def page_not_found(error):
+                return 'This page does not exist', 404
+
+        You can also register handlers for arbitrary exceptions::
+
+            @app.errorhandler(DatabaseError)
+            def special_exception_handler(error):
+                return 'Database connection failed', 500
+
+        .. versionadded:: 0.7
+            Use :meth:`register_error_handler` instead of modifying
+            :attr:`error_handler_spec` directly, for application wide error
+            handlers.
+
+        .. versionadded:: 0.7
+           One can now additionally also register custom exception types
+           that do not necessarily have to be a subclass of the
+           :class:`~werkzeug.exceptions.HTTPException` class.
+
+        :param code_or_exception: the code as integer for the handler, or
+                                  an arbitrary exception
+        """
+        def decorator(f):
+            self._register_error_handler(None, code_or_exception, f)
+            return f
+        return decorator
+
+    @setupmethod
+    def register_error_handler(self, code_or_exception, f):
+        """Alternative error attach function to the :meth:`errorhandler`
+        decorator that is more straightforward to use for non decorator
+        usage.
+
+        .. versionadded:: 0.7
+        """
+        self._register_error_handler(None, code_or_exception, f)
+
+    @setupmethod
+    def _register_error_handler(self, key, code_or_exception, f):
+        """
+        :type key: None|str
+        :type code_or_exception: int|T<=Exception
+        :type f: callable
+        """
+        if isinstance(code_or_exception, HTTPException):  # old broken behavior
+            raise ValueError(
+                'Tried to register a handler for an exception instance {0!r}.'
+                ' Handlers can only be registered for exception classes or'
+                ' HTTP error codes.'.format(code_or_exception)
+            )
+
+        try:
+            exc_class, code = self._get_exc_class_and_code(code_or_exception)
+        except KeyError:
+            raise KeyError(
+                "'{0}' is not a recognized HTTP error code. Use a subclass of"
+                " HTTPException with that code instead.".format(code_or_exception)
+            )
+
+        handlers = self.error_handler_spec.setdefault(key, {}).setdefault(code, {})
+        handlers[exc_class] = f
+
+    @setupmethod
+    def template_filter(self, name=None):
+        """A decorator that is used to register custom template filter.
+        You can specify a name for the filter, otherwise the function
+        name will be used. Example::
+
+          @app.template_filter()
+          def reverse(s):
+              return s[::-1]
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_template_filter(f, name=name)
+            return f
+        return decorator
+
+    @setupmethod
+    def add_template_filter(self, f, name=None):
+        """Register a custom template filter.  Works exactly like the
+        :meth:`template_filter` decorator.
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.filters[name or f.__name__] = f
+
+    @setupmethod
+    def template_test(self, name=None):
+        """A decorator that is used to register custom template test.
+        You can specify a name for the test, otherwise the function
+        name will be used. Example::
+
+          @app.template_test()
+          def is_prime(n):
+              if n == 2:
+                  return True
+              for i in range(2, int(math.ceil(math.sqrt(n))) + 1):
+                  if n % i == 0:
+                      return False
+              return True
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_template_test(f, name=name)
+            return f
+        return decorator
+
+    @setupmethod
+    def add_template_test(self, f, name=None):
+        """Register a custom template test.  Works exactly like the
+        :meth:`template_test` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.tests[name or f.__name__] = f
+
+    @setupmethod
+    def template_global(self, name=None):
+        """A decorator that is used to register a custom template global function.
+        You can specify a name for the global function, otherwise the function
+        name will be used. Example::
+
+            @app.template_global()
+            def double(n):
+                return 2 * n
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global function, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_template_global(f, name=name)
+            return f
+        return decorator
+
+    @setupmethod
+    def add_template_global(self, f, name=None):
+        """Register a custom template global function. Works exactly like the
+        :meth:`template_global` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global function, otherwise the
+                     function name will be used.
+        """
+        self.jinja_env.globals[name or f.__name__] = f
+
+    @setupmethod
+    def before_request(self, f):
+        """Registers a function to run before each request.
+
+        For example, this can be used to open a database connection, or to load
+        the logged in user from the session.
+
+        The function will be called without any arguments. If it returns a
+        non-None value, the value is handled as if it was the return value from
+        the view, and further request handling is stopped.
+        """
+        self.before_request_funcs.setdefault(None, []).append(f)
+        return f
+
+    @setupmethod
+    def before_first_request(self, f):
+        """Registers a function to be run before the first request to this
+        instance of the application.
+
+        The function will be called without any arguments and its return
+        value is ignored.
+
+        .. versionadded:: 0.8
+        """
+        self.before_first_request_funcs.append(f)
+        return f
+
+    @setupmethod
+    def after_request(self, f):
+        """Register a function to be run after each request.
+
+        Your function must take one parameter, an instance of
+        :attr:`response_class` and return a new response object or the
+        same (see :meth:`process_response`).
+
+        As of Flask 0.7 this function might not be executed at the end of the
+        request in case an unhandled exception occurred.
+        """
+        self.after_request_funcs.setdefault(None, []).append(f)
+        return f
+
+    @setupmethod
+    def teardown_request(self, f):
+        """Register a function to be run at the end of each request,
+        regardless of whether there was an exception or not.  These functions
+        are executed when the request context is popped, even if not an
+        actual request was performed.
+
+        Example::
+
+            ctx = app.test_request_context()
+            ctx.push()
+            ...
+            ctx.pop()
+
+        When ``ctx.pop()`` is executed in the above example, the teardown
+        functions are called just before the request context moves from the
+        stack of active contexts.  This becomes relevant if you are using
+        such constructs in tests.
+
+        Generally teardown functions must take every necessary step to avoid
+        that they will fail.  If they do execute code that might fail they
+        will have to surround the execution of these code by try/except
+        statements and log occurring errors.
+
+        When a teardown function was called because of an exception it will
+        be passed an error object.
+
+        The return values of teardown functions are ignored.
+
+        .. admonition:: Debug Note
+
+           In debug mode Flask will not tear down a request on an exception
+           immediately.  Instead it will keep it alive so that the interactive
+           debugger can still access it.  This behavior can be controlled
+           by the ``PRESERVE_CONTEXT_ON_EXCEPTION`` configuration variable.
+        """
+        self.teardown_request_funcs.setdefault(None, []).append(f)
+        return f
+
+    @setupmethod
+    def teardown_appcontext(self, f):
+        """Registers a function to be called when the application context
+        ends.  These functions are typically also called when the request
+        context is popped.
+
+        Example::
+
+            ctx = app.app_context()
+            ctx.push()
+            ...
+            ctx.pop()
+
+        When ``ctx.pop()`` is executed in the above example, the teardown
+        functions are called just before the app context moves from the
+        stack of active contexts.  This becomes relevant if you are using
+        such constructs in tests.
+
+        Since a request context typically also manages an application
+        context it would also be called when you pop a request context.
+
+        When a teardown function was called because of an unhandled exception
+        it will be passed an error object. If an :meth:`errorhandler` is
+        registered, it will handle the exception and the teardown will not
+        receive it.
+
+        The return values of teardown functions are ignored.
+
+        .. versionadded:: 0.9
+        """
+        self.teardown_appcontext_funcs.append(f)
+        return f
+
+    @setupmethod
+    def context_processor(self, f):
+        """Registers a template context processor function."""
+        self.template_context_processors[None].append(f)
+        return f
+
+    @setupmethod
+    def shell_context_processor(self, f):
+        """Registers a shell context processor function.
+
+        .. versionadded:: 0.11
+        """
+        self.shell_context_processors.append(f)
+        return f
+
+    @setupmethod
+    def url_value_preprocessor(self, f):
+        """Register a URL value preprocessor function for all view
+        functions in the application. These functions will be called before the
+        :meth:`before_request` functions.
+
+        The function can modify the values captured from the matched url before
+        they are passed to the view. For example, this can be used to pop a
+        common language code value and place it in ``g`` rather than pass it to
+        every view.
+
+        The function is passed the endpoint name and values dict. The return
+        value is ignored.
+        """
+        self.url_value_preprocessors.setdefault(None, []).append(f)
+        return f
+
+    @setupmethod
+    def url_defaults(self, f):
+        """Callback function for URL defaults for all view functions of the
+        application.  It's called with the endpoint and values and should
+        update the values passed in place.
+        """
+        self.url_default_functions.setdefault(None, []).append(f)
+        return f
+
+    def _find_error_handler(self, e):
+        """Return a registered error handler for an exception in this order:
+        blueprint handler for a specific code, app handler for a specific code,
+        blueprint handler for an exception class, app handler for an exception
+        class, or ``None`` if a suitable handler is not found.
+        """
+        exc_class, code = self._get_exc_class_and_code(type(e))
+
+        for name, c in (
+            (request.blueprint, code), (None, code),
+            (request.blueprint, None), (None, None)
+        ):
+            handler_map = self.error_handler_spec.setdefault(name, {}).get(c)
+
+            if not handler_map:
+                continue
+
+            for cls in exc_class.__mro__:
+                handler = handler_map.get(cls)
+
+                if handler is not None:
+                    return handler
+
+    def handle_http_exception(self, e):
+        """Handles an HTTP exception.  By default this will invoke the
+        registered error handlers and fall back to returning the
+        exception as response.
+
+        .. versionchanged:: 1.0.3
+            ``RoutingException``, used internally for actions such as
+             slash redirects during routing, is not passed to error
+             handlers.
+
+        .. versionchanged:: 1.0
+            Exceptions are looked up by code *and* by MRO, so
+            ``HTTPExcpetion`` subclasses can be handled with a catch-all
+            handler for the base ``HTTPException``.
+
+        .. versionadded:: 0.3
+        """
+        # Proxy exceptions don't have error codes.  We want to always return
+        # those unchanged as errors
+        if e.code is None:
+            return e
+
+        # RoutingExceptions are used internally to trigger routing
+        # actions, such as slash redirects raising RequestRedirect. They
+        # are not raised or handled in user code.
+        if isinstance(e, RoutingException):
+            return e
+
+        handler = self._find_error_handler(e)
+        if handler is None:
+            return e
+        return handler(e)
+
+    def trap_http_exception(self, e):
+        """Checks if an HTTP exception should be trapped or not.  By default
+        this will return ``False`` for all exceptions except for a bad request
+        key error if ``TRAP_BAD_REQUEST_ERRORS`` is set to ``True``.  It
+        also returns ``True`` if ``TRAP_HTTP_EXCEPTIONS`` is set to ``True``.
+
+        This is called for all HTTP exceptions raised by a view function.
+        If it returns ``True`` for any exception the error handler for this
+        exception is not called and it shows up as regular exception in the
+        traceback.  This is helpful for debugging implicitly raised HTTP
+        exceptions.
+
+        .. versionchanged:: 1.0
+            Bad request errors are not trapped by default in debug mode.
+
+        .. versionadded:: 0.8
+        """
+        if self.config['TRAP_HTTP_EXCEPTIONS']:
+            return True
+
+        trap_bad_request = self.config['TRAP_BAD_REQUEST_ERRORS']
+
+        # if unset, trap key errors in debug mode
+        if (
+            trap_bad_request is None and self.debug
+            and isinstance(e, BadRequestKeyError)
+        ):
+            return True
+
+        if trap_bad_request:
+            return isinstance(e, BadRequest)
+
+        return False
+
+    def handle_user_exception(self, e):
+        """This method is called whenever an exception occurs that
+        should be handled. A special case is :class:`~werkzeug
+        .exceptions.HTTPException` which is forwarded to the
+        :meth:`handle_http_exception` method. This function will either
+        return a response value or reraise the exception with the same
+        traceback.
+
+        .. versionchanged:: 1.0
+            Key errors raised from request data like ``form`` show the
+            bad key in debug mode rather than a generic bad request
+            message.
+
+        .. versionadded:: 0.7
+        """
+        exc_type, exc_value, tb = sys.exc_info()
+        assert exc_value is e
+        # ensure not to trash sys.exc_info() at that point in case someone
+        # wants the traceback preserved in handle_http_exception.  Of course
+        # we cannot prevent users from trashing it themselves in a custom
+        # trap_http_exception method so that's their fault then.
+
+        if isinstance(e, BadRequestKeyError):
+            if self.debug or self.config["TRAP_BAD_REQUEST_ERRORS"]:
+                # Werkzeug < 0.15 doesn't add the KeyError to the 400
+                # message, add it in manually.
+                description = e.get_description()
+
+                if e.args[0] not in description:
+                    e.description = "KeyError: '{}'".format(*e.args)
+            else:
+                # Werkzeug >= 0.15 does add it, remove it in production
+                e.args = ()
+
+        if isinstance(e, HTTPException) and not self.trap_http_exception(e):
+            return self.handle_http_exception(e)
+
+        handler = self._find_error_handler(e)
+
+        if handler is None:
+            reraise(exc_type, exc_value, tb)
+        return handler(e)
+
+    def handle_exception(self, e):
+        """Default exception handling that kicks in when an exception
+        occurs that is not caught.  In debug mode the exception will
+        be re-raised immediately, otherwise it is logged and the handler
+        for a 500 internal server error is used.  If no such handler
+        exists, a default 500 internal server error message is displayed.
+
+        .. versionadded:: 0.3
+        """
+        exc_type, exc_value, tb = sys.exc_info()
+
+        got_request_exception.send(self, exception=e)
+        handler = self._find_error_handler(InternalServerError())
+
+        if self.propagate_exceptions:
+            # if we want to repropagate the exception, we can attempt to
+            # raise it with the whole traceback in case we can do that
+            # (the function was actually called from the except part)
+            # otherwise, we just raise the error again
+            if exc_value is e:
+                reraise(exc_type, exc_value, tb)
+            else:
+                raise e
+
+        self.log_exception((exc_type, exc_value, tb))
+        if handler is None:
+            return InternalServerError()
+        return self.finalize_request(handler(e), from_error_handler=True)
+
+    def log_exception(self, exc_info):
+        """Logs an exception.  This is called by :meth:`handle_exception`
+        if debugging is disabled and right before the handler is called.
+        The default implementation logs the exception as error on the
+        :attr:`logger`.
+
+        .. versionadded:: 0.8
+        """
+        self.logger.error('Exception on %s [%s]' % (
+            request.path,
+            request.method
+        ), exc_info=exc_info)
+
+    def raise_routing_exception(self, request):
+        """Exceptions that are recording during routing are reraised with
+        this method.  During debug we are not reraising redirect requests
+        for non ``GET``, ``HEAD``, or ``OPTIONS`` requests and we're raising
+        a different error instead to help debug situations.
+
+        :internal:
+        """
+        if not self.debug \
+           or not isinstance(request.routing_exception, RequestRedirect) \
+           or request.method in ('GET', 'HEAD', 'OPTIONS'):
+            raise request.routing_exception
+
+        from .debughelpers import FormDataRoutingRedirect
+        raise FormDataRoutingRedirect(request)
+
+    def dispatch_request(self):
+        """Does the request dispatching.  Matches the URL and returns the
+        return value of the view or error handler.  This does not have to
+        be a response object.  In order to convert the return value to a
+        proper response object, call :func:`make_response`.
+
+        .. versionchanged:: 0.7
+           This no longer does the exception handling, this code was
+           moved to the new :meth:`full_dispatch_request`.
+        """
+        req = _request_ctx_stack.top.request
+        if req.routing_exception is not None:
+            self.raise_routing_exception(req)
+        rule = req.url_rule
+        # if we provide automatic options for this URL and the
+        # request came with the OPTIONS method, reply automatically
+        if getattr(rule, 'provide_automatic_options', False) \
+           and req.method == 'OPTIONS':
+            return self.make_default_options_response()
+        # otherwise dispatch to the handler for that endpoint
+        return self.view_functions[rule.endpoint](**req.view_args)
+
+    def full_dispatch_request(self):
+        """Dispatches the request and on top of that performs request
+        pre and postprocessing as well as HTTP exception catching and
+        error handling.
+
+        .. versionadded:: 0.7
+        """
+        self.try_trigger_before_first_request_functions()
+        try:
+            request_started.send(self)
+            rv = self.preprocess_request()
+            if rv is None:
+                rv = self.dispatch_request()
+        except Exception as e:
+            rv = self.handle_user_exception(e)
+        return self.finalize_request(rv)
+
+    def finalize_request(self, rv, from_error_handler=False):
+        """Given the return value from a view function this finalizes
+        the request by converting it into a response and invoking the
+        postprocessing functions.  This is invoked for both normal
+        request dispatching as well as error handlers.
+
+        Because this means that it might be called as a result of a
+        failure a special safe mode is available which can be enabled
+        with the `from_error_handler` flag.  If enabled, failures in
+        response processing will be logged and otherwise ignored.
+
+        :internal:
+        """
+        response = self.make_response(rv)
+        try:
+            response = self.process_response(response)
+            request_finished.send(self, response=response)
+        except Exception:
+            if not from_error_handler:
+                raise
+            self.logger.exception('Request finalizing failed with an '
+                                  'error while handling an error')
+        return response
+
+    def try_trigger_before_first_request_functions(self):
+        """Called before each request and will ensure that it triggers
+        the :attr:`before_first_request_funcs` and only exactly once per
+        application instance (which means process usually).
+
+        :internal:
+        """
+        if self._got_first_request:
+            return
+        with self._before_request_lock:
+            if self._got_first_request:
+                return
+            for func in self.before_first_request_funcs:
+                func()
+            self._got_first_request = True
+
+    def make_default_options_response(self):
+        """This method is called to create the default ``OPTIONS`` response.
+        This can be changed through subclassing to change the default
+        behavior of ``OPTIONS`` responses.
+
+        .. versionadded:: 0.7
+        """
+        adapter = _request_ctx_stack.top.url_adapter
+        if hasattr(adapter, 'allowed_methods'):
+            methods = adapter.allowed_methods()
+        else:
+            # fallback for Werkzeug < 0.7
+            methods = []
+            try:
+                adapter.match(method='--')
+            except MethodNotAllowed as e:
+                methods = e.valid_methods
+            except HTTPException as e:
+                pass
+        rv = self.response_class()
+        rv.allow.update(methods)
+        return rv
+
+    def should_ignore_error(self, error):
+        """This is called to figure out if an error should be ignored
+        or not as far as the teardown system is concerned.  If this
+        function returns ``True`` then the teardown handlers will not be
+        passed the error.
+
+        .. versionadded:: 0.10
+        """
+        return False
+
+    def make_response(self, rv):
+        """Convert the return value from a view function to an instance of
+        :attr:`response_class`.
+
+        :param rv: the return value from the view function. The view function
+            must return a response. Returning ``None``, or the view ending
+            without returning, is not allowed. The following types are allowed
+            for ``view_rv``:
+
+            ``str`` (``unicode`` in Python 2)
+                A response object is created with the string encoded to UTF-8
+                as the body.
+
+            ``bytes`` (``str`` in Python 2)
+                A response object is created with the bytes as the body.
+
+            ``tuple``
+                Either ``(body, status, headers)``, ``(body, status)``, or
+                ``(body, headers)``, where ``body`` is any of the other types
+                allowed here, ``status`` is a string or an integer, and
+                ``headers`` is a dictionary or a list of ``(key, value)``
+                tuples. If ``body`` is a :attr:`response_class` instance,
+                ``status`` overwrites the exiting value and ``headers`` are
+                extended.
+
+            :attr:`response_class`
+                The object is returned unchanged.
+
+            other :class:`~werkzeug.wrappers.Response` class
+                The object is coerced to :attr:`response_class`.
+
+            :func:`callable`
+                The function is called as a WSGI application. The result is
+                used to create a response object.
+
+        .. versionchanged:: 0.9
+           Previously a tuple was interpreted as the arguments for the
+           response object.
+        """
+
+        status = headers = None
+
+        # unpack tuple returns
+        if isinstance(rv, tuple):
+            len_rv = len(rv)
+
+            # a 3-tuple is unpacked directly
+            if len_rv == 3:
+                rv, status, headers = rv
+            # decide if a 2-tuple has status or headers
+            elif len_rv == 2:
+                if isinstance(rv[1], (Headers, dict, tuple, list)):
+                    rv, headers = rv
+                else:
+                    rv, status = rv
+            # other sized tuples are not allowed
+            else:
+                raise TypeError(
+                    'The view function did not return a valid response tuple.'
+                    ' The tuple must have the form (body, status, headers),'
+                    ' (body, status), or (body, headers).'
+                )
+
+        # the body must not be None
+        if rv is None:
+            raise TypeError(
+                'The view function did not return a valid response. The'
+                ' function either returned None or ended without a return'
+                ' statement.'
+            )
+
+        # make sure the body is an instance of the response class
+        if not isinstance(rv, self.response_class):
+            if isinstance(rv, (text_type, bytes, bytearray)):
+                # let the response class set the status and headers instead of
+                # waiting to do it manually, so that the class can handle any
+                # special logic
+                rv = self.response_class(rv, status=status, headers=headers)
+                status = headers = None
+            else:
+                # evaluate a WSGI callable, or coerce a different response
+                # class to the correct type
+                try:
+                    rv = self.response_class.force_type(rv, request.environ)
+                except TypeError as e:
+                    new_error = TypeError(
+                        '{e}\nThe view function did not return a valid'
+                        ' response. The return type must be a string, tuple,'
+                        ' Response instance, or WSGI callable, but it was a'
+                        ' {rv.__class__.__name__}.'.format(e=e, rv=rv)
+                    )
+                    reraise(TypeError, new_error, sys.exc_info()[2])
+
+        # prefer the status if it was provided
+        if status is not None:
+            if isinstance(status, (text_type, bytes, bytearray)):
+                rv.status = status
+            else:
+                rv.status_code = status
+
+        # extend existing headers with provided headers
+        if headers:
+            rv.headers.extend(headers)
+
+        return rv
+
+    def create_url_adapter(self, request):
+        """Creates a URL adapter for the given request. The URL adapter
+        is created at a point where the request context is not yet set
+        up so the request is passed explicitly.
+
+        .. versionadded:: 0.6
+
+        .. versionchanged:: 0.9
+           This can now also be called without a request object when the
+           URL adapter is created for the application context.
+
+        .. versionchanged:: 1.0
+            :data:`SERVER_NAME` no longer implicitly enables subdomain
+            matching. Use :attr:`subdomain_matching` instead.
+        """
+        if request is not None:
+            # If subdomain matching is disabled (the default), use the
+            # default subdomain in all cases. This should be the default
+            # in Werkzeug but it currently does not have that feature.
+            subdomain = ((self.url_map.default_subdomain or None)
+                         if not self.subdomain_matching else None)
+            return self.url_map.bind_to_environ(
+                request.environ,
+                server_name=self.config['SERVER_NAME'],
+                subdomain=subdomain)
+        # We need at the very least the server name to be set for this
+        # to work.
+        if self.config['SERVER_NAME'] is not None:
+            return self.url_map.bind(
+                self.config['SERVER_NAME'],
+                script_name=self.config['APPLICATION_ROOT'],
+                url_scheme=self.config['PREFERRED_URL_SCHEME'])
+
+    def inject_url_defaults(self, endpoint, values):
+        """Injects the URL defaults for the given endpoint directly into
+        the values dictionary passed.  This is used internally and
+        automatically called on URL building.
+
+        .. versionadded:: 0.7
+        """
+        funcs = self.url_default_functions.get(None, ())
+        if '.' in endpoint:
+            bp = endpoint.rsplit('.', 1)[0]
+            funcs = chain(funcs, self.url_default_functions.get(bp, ()))
+        for func in funcs:
+            func(endpoint, values)
+
+    def handle_url_build_error(self, error, endpoint, values):
+        """Handle :class:`~werkzeug.routing.BuildError` on :meth:`url_for`.
+        """
+        exc_type, exc_value, tb = sys.exc_info()
+        for handler in self.url_build_error_handlers:
+            try:
+                rv = handler(error, endpoint, values)
+                if rv is not None:
+                    return rv
+            except BuildError as e:
+                # make error available outside except block (py3)
+                error = e
+
+        # At this point we want to reraise the exception.  If the error is
+        # still the same one we can reraise it with the original traceback,
+        # otherwise we raise it from here.
+        if error is exc_value:
+            reraise(exc_type, exc_value, tb)
+        raise error
+
+    def preprocess_request(self):
+        """Called before the request is dispatched. Calls
+        :attr:`url_value_preprocessors` registered with the app and the
+        current blueprint (if any). Then calls :attr:`before_request_funcs`
+        registered with the app and the blueprint.
+
+        If any :meth:`before_request` handler returns a non-None value, the
+        value is handled as if it was the return value from the view, and
+        further request handling is stopped.
+        """
+
+        bp = _request_ctx_stack.top.request.blueprint
+
+        funcs = self.url_value_preprocessors.get(None, ())
+        if bp is not None and bp in self.url_value_preprocessors:
+            funcs = chain(funcs, self.url_value_preprocessors[bp])
+        for func in funcs:
+            func(request.endpoint, request.view_args)
+
+        funcs = self.before_request_funcs.get(None, ())
+        if bp is not None and bp in self.before_request_funcs:
+            funcs = chain(funcs, self.before_request_funcs[bp])
+        for func in funcs:
+            rv = func()
+            if rv is not None:
+                return rv
+
+    def process_response(self, response):
+        """Can be overridden in order to modify the response object
+        before it's sent to the WSGI server.  By default this will
+        call all the :meth:`after_request` decorated functions.
+
+        .. versionchanged:: 0.5
+           As of Flask 0.5 the functions registered for after request
+           execution are called in reverse order of registration.
+
+        :param response: a :attr:`response_class` object.
+        :return: a new response object or the same, has to be an
+                 instance of :attr:`response_class`.
+        """
+        ctx = _request_ctx_stack.top
+        bp = ctx.request.blueprint
+        funcs = ctx._after_request_functions
+        if bp is not None and bp in self.after_request_funcs:
+            funcs = chain(funcs, reversed(self.after_request_funcs[bp]))
+        if None in self.after_request_funcs:
+            funcs = chain(funcs, reversed(self.after_request_funcs[None]))
+        for handler in funcs:
+            response = handler(response)
+        if not self.session_interface.is_null_session(ctx.session):
+            self.session_interface.save_session(self, ctx.session, response)
+        return response
+
+    def do_teardown_request(self, exc=_sentinel):
+        """Called after the request is dispatched and the response is
+        returned, right before the request context is popped.
+
+        This calls all functions decorated with
+        :meth:`teardown_request`, and :meth:`Blueprint.teardown_request`
+        if a blueprint handled the request. Finally, the
+        :data:`request_tearing_down` signal is sent.
+
+        This is called by
+        :meth:`RequestContext.pop() <flask.ctx.RequestContext.pop>`,
+        which may be delayed during testing to maintain access to
+        resources.
+
+        :param exc: An unhandled exception raised while dispatching the
+            request. Detected from the current exception information if
+            not passed. Passed to each teardown function.
+
+        .. versionchanged:: 0.9
+            Added the ``exc`` argument.
+        """
+        if exc is _sentinel:
+            exc = sys.exc_info()[1]
+        funcs = reversed(self.teardown_request_funcs.get(None, ()))
+        bp = _request_ctx_stack.top.request.blueprint
+        if bp is not None and bp in self.teardown_request_funcs:
+            funcs = chain(funcs, reversed(self.teardown_request_funcs[bp]))
+        for func in funcs:
+            func(exc)
+        request_tearing_down.send(self, exc=exc)
+
+    def do_teardown_appcontext(self, exc=_sentinel):
+        """Called right before the application context is popped.
+
+        When handling a request, the application context is popped
+        after the request context. See :meth:`do_teardown_request`.
+
+        This calls all functions decorated with
+        :meth:`teardown_appcontext`. Then the
+        :data:`appcontext_tearing_down` signal is sent.
+
+        This is called by
+        :meth:`AppContext.pop() <flask.ctx.AppContext.pop>`.
+
+        .. versionadded:: 0.9
+        """
+        if exc is _sentinel:
+            exc = sys.exc_info()[1]
+        for func in reversed(self.teardown_appcontext_funcs):
+            func(exc)
+        appcontext_tearing_down.send(self, exc=exc)
+
+    def app_context(self):
+        """Create an :class:`~flask.ctx.AppContext`. Use as a ``with``
+        block to push the context, which will make :data:`current_app`
+        point at this application.
+
+        An application context is automatically pushed by
+        :meth:`RequestContext.push() <flask.ctx.RequestContext.push>`
+        when handling a request, and when running a CLI command. Use
+        this to manually create a context outside of these situations.
+
+        ::
+
+            with app.app_context():
+                init_db()
+
+        See :doc:`/appcontext`.
+
+        .. versionadded:: 0.9
+        """
+        return AppContext(self)
+
+    def request_context(self, environ):
+        """Create a :class:`~flask.ctx.RequestContext` representing a
+        WSGI environment. Use a ``with`` block to push the context,
+        which will make :data:`request` point at this request.
+
+        See :doc:`/reqcontext`.
+
+        Typically you should not call this from your own code. A request
+        context is automatically pushed by the :meth:`wsgi_app` when
+        handling a request. Use :meth:`test_request_context` to create
+        an environment and context instead of this method.
+
+        :param environ: a WSGI environment
+        """
+        return RequestContext(self, environ)
+
+    def test_request_context(self, *args, **kwargs):
+        """Create a :class:`~flask.ctx.RequestContext` for a WSGI
+        environment created from the given values. This is mostly useful
+        during testing, where you may want to run a function that uses
+        request data without dispatching a full request.
+
+        See :doc:`/reqcontext`.
+
+        Use a ``with`` block to push the context, which will make
+        :data:`request` point at the request for the created
+        environment. ::
+
+            with test_request_context(...):
+                generate_report()
+
+        When using the shell, it may be easier to push and pop the
+        context manually to avoid indentation. ::
+
+            ctx = app.test_request_context(...)
+            ctx.push()
+            ...
+            ctx.pop()
+
+        Takes the same arguments as Werkzeug's
+        :class:`~werkzeug.test.EnvironBuilder`, with some defaults from
+        the application. See the linked Werkzeug docs for most of the
+        available arguments. Flask-specific behavior is listed here.
+
+        :param path: URL path being requested.
+        :param base_url: Base URL where the app is being served, which
+            ``path`` is relative to. If not given, built from
+            :data:`PREFERRED_URL_SCHEME`, ``subdomain``,
+            :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`.
+        :param subdomain: Subdomain name to append to
+            :data:`SERVER_NAME`.
+        :param url_scheme: Scheme to use instead of
+            :data:`PREFERRED_URL_SCHEME`.
+        :param data: The request body, either as a string or a dict of
+            form keys and values.
+        :param json: If given, this is serialized as JSON and passed as
+            ``data``. Also defaults ``content_type`` to
+            ``application/json``.
+        :param args: other positional arguments passed to
+            :class:`~werkzeug.test.EnvironBuilder`.
+        :param kwargs: other keyword arguments passed to
+            :class:`~werkzeug.test.EnvironBuilder`.
+        """
+        from flask.testing import make_test_environ_builder
+
+        builder = make_test_environ_builder(self, *args, **kwargs)
+
+        try:
+            return self.request_context(builder.get_environ())
+        finally:
+            builder.close()
+
+    def wsgi_app(self, environ, start_response):
+        """The actual WSGI application. This is not implemented in
+        :meth:`__call__` so that middlewares can be applied without
+        losing a reference to the app object. Instead of doing this::
+
+            app = MyMiddleware(app)
+
+        It's a better idea to do this instead::
+
+            app.wsgi_app = MyMiddleware(app.wsgi_app)
+
+        Then you still have the original application object around and
+        can continue to call methods on it.
+
+        .. versionchanged:: 0.7
+            Teardown events for the request and app contexts are called
+            even if an unhandled error occurs. Other events may not be
+            called depending on when an error occurs during dispatch.
+            See :ref:`callbacks-and-errors`.
+
+        :param environ: A WSGI environment.
+        :param start_response: A callable accepting a status code,
+            a list of headers, and an optional exception context to
+            start the response.
+        """
+        ctx = self.request_context(environ)
+        error = None
+        try:
+            try:
+                ctx.push()
+                response = self.full_dispatch_request()
+            except Exception as e:
+                error = e
+                response = self.handle_exception(e)
+            except:
+                error = sys.exc_info()[1]
+                raise
+            return response(environ, start_response)
+        finally:
+            if self.should_ignore_error(error):
+                error = None
+            ctx.auto_pop(error)
+
+    def __call__(self, environ, start_response):
+        """The WSGI server calls the Flask application object as the
+        WSGI application. This calls :meth:`wsgi_app` which can be
+        wrapped to applying middleware."""
+        return self.wsgi_app(environ, start_response)
+
+    def __repr__(self):
+        return '<%s %r>' % (
+            self.__class__.__name__,
+            self.name,
+        )
diff --git a/python/flask/blueprints.py b/python/flask/blueprints.py
new file mode 100644
index 0000000..c2158fe
--- /dev/null
+++ b/python/flask/blueprints.py
@@ -0,0 +1,447 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.blueprints
+    ~~~~~~~~~~~~~~~~
+
+    Blueprints are the recommended way to implement larger or more
+    pluggable applications in Flask 0.7 and later.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+from functools import update_wrapper
+
+from .helpers import _PackageBoundObject, _endpoint_from_view_func
+
+
+class BlueprintSetupState(object):
+    """Temporary holder object for registering a blueprint with the
+    application.  An instance of this class is created by the
+    :meth:`~flask.Blueprint.make_setup_state` method and later passed
+    to all register callback functions.
+    """
+
+    def __init__(self, blueprint, app, options, first_registration):
+        #: a reference to the current application
+        self.app = app
+
+        #: a reference to the blueprint that created this setup state.
+        self.blueprint = blueprint
+
+        #: a dictionary with all options that were passed to the
+        #: :meth:`~flask.Flask.register_blueprint` method.
+        self.options = options
+
+        #: as blueprints can be registered multiple times with the
+        #: application and not everything wants to be registered
+        #: multiple times on it, this attribute can be used to figure
+        #: out if the blueprint was registered in the past already.
+        self.first_registration = first_registration
+
+        subdomain = self.options.get('subdomain')
+        if subdomain is None:
+            subdomain = self.blueprint.subdomain
+
+        #: The subdomain that the blueprint should be active for, ``None``
+        #: otherwise.
+        self.subdomain = subdomain
+
+        url_prefix = self.options.get('url_prefix')
+        if url_prefix is None:
+            url_prefix = self.blueprint.url_prefix
+        #: The prefix that should be used for all URLs defined on the
+        #: blueprint.
+        self.url_prefix = url_prefix
+
+        #: A dictionary with URL defaults that is added to each and every
+        #: URL that was defined with the blueprint.
+        self.url_defaults = dict(self.blueprint.url_values_defaults)
+        self.url_defaults.update(self.options.get('url_defaults', ()))
+
+    def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
+        """A helper method to register a rule (and optionally a view function)
+        to the application.  The endpoint is automatically prefixed with the
+        blueprint's name.
+        """
+        if self.url_prefix is not None:
+            if rule:
+                rule = '/'.join((
+                    self.url_prefix.rstrip('/'), rule.lstrip('/')))
+            else:
+                rule = self.url_prefix
+        options.setdefault('subdomain', self.subdomain)
+        if endpoint is None:
+            endpoint = _endpoint_from_view_func(view_func)
+        defaults = self.url_defaults
+        if 'defaults' in options:
+            defaults = dict(defaults, **options.pop('defaults'))
+        self.app.add_url_rule(rule, '%s.%s' % (self.blueprint.name, endpoint),
+                              view_func, defaults=defaults, **options)
+
+
+class Blueprint(_PackageBoundObject):
+    """Represents a blueprint.  A blueprint is an object that records
+    functions that will be called with the
+    :class:`~flask.blueprints.BlueprintSetupState` later to register functions
+    or other things on the main application.  See :ref:`blueprints` for more
+    information.
+
+    .. versionadded:: 0.7
+    """
+
+    warn_on_modifications = False
+    _got_registered_once = False
+
+    #: Blueprint local JSON decoder class to use.
+    #: Set to ``None`` to use the app's :class:`~flask.app.Flask.json_encoder`.
+    json_encoder = None
+    #: Blueprint local JSON decoder class to use.
+    #: Set to ``None`` to use the app's :class:`~flask.app.Flask.json_decoder`.
+    json_decoder = None
+
+    # TODO remove the next three attrs when Sphinx :inherited-members: works
+    # https://github.com/sphinx-doc/sphinx/issues/741
+
+    #: The name of the package or module that this app belongs to. Do not
+    #: change this once it is set by the constructor.
+    import_name = None
+
+    #: Location of the template files to be added to the template lookup.
+    #: ``None`` if templates should not be added.
+    template_folder = None
+
+    #: Absolute path to the package on the filesystem. Used to look up
+    #: resources contained in the package.
+    root_path = None
+
+    def __init__(self, name, import_name, static_folder=None,
+                 static_url_path=None, template_folder=None,
+                 url_prefix=None, subdomain=None, url_defaults=None,
+                 root_path=None):
+        _PackageBoundObject.__init__(self, import_name, template_folder,
+                                     root_path=root_path)
+        self.name = name
+        self.url_prefix = url_prefix
+        self.subdomain = subdomain
+        self.static_folder = static_folder
+        self.static_url_path = static_url_path
+        self.deferred_functions = []
+        if url_defaults is None:
+            url_defaults = {}
+        self.url_values_defaults = url_defaults
+
+    def record(self, func):
+        """Registers a function that is called when the blueprint is
+        registered on the application.  This function is called with the
+        state as argument as returned by the :meth:`make_setup_state`
+        method.
+        """
+        if self._got_registered_once and self.warn_on_modifications:
+            from warnings import warn
+            warn(Warning('The blueprint was already registered once '
+                         'but is getting modified now.  These changes '
+                         'will not show up.'))
+        self.deferred_functions.append(func)
+
+    def record_once(self, func):
+        """Works like :meth:`record` but wraps the function in another
+        function that will ensure the function is only called once.  If the
+        blueprint is registered a second time on the application, the
+        function passed is not called.
+        """
+        def wrapper(state):
+            if state.first_registration:
+                func(state)
+        return self.record(update_wrapper(wrapper, func))
+
+    def make_setup_state(self, app, options, first_registration=False):
+        """Creates an instance of :meth:`~flask.blueprints.BlueprintSetupState`
+        object that is later passed to the register callback functions.
+        Subclasses can override this to return a subclass of the setup state.
+        """
+        return BlueprintSetupState(self, app, options, first_registration)
+
+    def register(self, app, options, first_registration=False):
+        """Called by :meth:`Flask.register_blueprint` to register all views
+        and callbacks registered on the blueprint with the application. Creates
+        a :class:`.BlueprintSetupState` and calls each :meth:`record` callback
+        with it.
+
+        :param app: The application this blueprint is being registered with.
+        :param options: Keyword arguments forwarded from
+            :meth:`~Flask.register_blueprint`.
+        :param first_registration: Whether this is the first time this
+            blueprint has been registered on the application.
+        """
+        self._got_registered_once = True
+        state = self.make_setup_state(app, options, first_registration)
+
+        if self.has_static_folder:
+            state.add_url_rule(
+                self.static_url_path + '/<path:filename>',
+                view_func=self.send_static_file, endpoint='static'
+            )
+
+        for deferred in self.deferred_functions:
+            deferred(state)
+
+    def route(self, rule, **options):
+        """Like :meth:`Flask.route` but for a blueprint.  The endpoint for the
+        :func:`url_for` function is prefixed with the name of the blueprint.
+        """
+        def decorator(f):
+            endpoint = options.pop("endpoint", f.__name__)
+            self.add_url_rule(rule, endpoint, f, **options)
+            return f
+        return decorator
+
+    def add_url_rule(self, rule, endpoint=None, view_func=None, **options):
+        """Like :meth:`Flask.add_url_rule` but for a blueprint.  The endpoint for
+        the :func:`url_for` function is prefixed with the name of the blueprint.
+        """
+        if endpoint:
+            assert '.' not in endpoint, "Blueprint endpoints should not contain dots"
+        if view_func and hasattr(view_func, '__name__'):
+            assert '.' not in view_func.__name__, "Blueprint view function name should not contain dots"
+        self.record(lambda s:
+            s.add_url_rule(rule, endpoint, view_func, **options))
+
+    def endpoint(self, endpoint):
+        """Like :meth:`Flask.endpoint` but for a blueprint.  This does not
+        prefix the endpoint with the blueprint name, this has to be done
+        explicitly by the user of this method.  If the endpoint is prefixed
+        with a `.` it will be registered to the current blueprint, otherwise
+        it's an application independent endpoint.
+        """
+        def decorator(f):
+            def register_endpoint(state):
+                state.app.view_functions[endpoint] = f
+            self.record_once(register_endpoint)
+            return f
+        return decorator
+
+    def app_template_filter(self, name=None):
+        """Register a custom template filter, available application wide.  Like
+        :meth:`Flask.template_filter` but for a blueprint.
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_app_template_filter(f, name=name)
+            return f
+        return decorator
+
+    def add_app_template_filter(self, f, name=None):
+        """Register a custom template filter, available application wide.  Like
+        :meth:`Flask.add_template_filter` but for a blueprint.  Works exactly
+        like the :meth:`app_template_filter` decorator.
+
+        :param name: the optional name of the filter, otherwise the
+                     function name will be used.
+        """
+        def register_template(state):
+            state.app.jinja_env.filters[name or f.__name__] = f
+        self.record_once(register_template)
+
+    def app_template_test(self, name=None):
+        """Register a custom template test, available application wide.  Like
+        :meth:`Flask.template_test` but for a blueprint.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_app_template_test(f, name=name)
+            return f
+        return decorator
+
+    def add_app_template_test(self, f, name=None):
+        """Register a custom template test, available application wide.  Like
+        :meth:`Flask.add_template_test` but for a blueprint.  Works exactly
+        like the :meth:`app_template_test` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the test, otherwise the
+                     function name will be used.
+        """
+        def register_template(state):
+            state.app.jinja_env.tests[name or f.__name__] = f
+        self.record_once(register_template)
+
+    def app_template_global(self, name=None):
+        """Register a custom template global, available application wide.  Like
+        :meth:`Flask.template_global` but for a blueprint.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global, otherwise the
+                     function name will be used.
+        """
+        def decorator(f):
+            self.add_app_template_global(f, name=name)
+            return f
+        return decorator
+
+    def add_app_template_global(self, f, name=None):
+        """Register a custom template global, available application wide.  Like
+        :meth:`Flask.add_template_global` but for a blueprint.  Works exactly
+        like the :meth:`app_template_global` decorator.
+
+        .. versionadded:: 0.10
+
+        :param name: the optional name of the global, otherwise the
+                     function name will be used.
+        """
+        def register_template(state):
+            state.app.jinja_env.globals[name or f.__name__] = f
+        self.record_once(register_template)
+
+    def before_request(self, f):
+        """Like :meth:`Flask.before_request` but for a blueprint.  This function
+        is only executed before each request that is handled by a function of
+        that blueprint.
+        """
+        self.record_once(lambda s: s.app.before_request_funcs
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def before_app_request(self, f):
+        """Like :meth:`Flask.before_request`.  Such a function is executed
+        before each request, even if outside of a blueprint.
+        """
+        self.record_once(lambda s: s.app.before_request_funcs
+            .setdefault(None, []).append(f))
+        return f
+
+    def before_app_first_request(self, f):
+        """Like :meth:`Flask.before_first_request`.  Such a function is
+        executed before the first request to the application.
+        """
+        self.record_once(lambda s: s.app.before_first_request_funcs.append(f))
+        return f
+
+    def after_request(self, f):
+        """Like :meth:`Flask.after_request` but for a blueprint.  This function
+        is only executed after each request that is handled by a function of
+        that blueprint.
+        """
+        self.record_once(lambda s: s.app.after_request_funcs
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def after_app_request(self, f):
+        """Like :meth:`Flask.after_request` but for a blueprint.  Such a function
+        is executed after each request, even if outside of the blueprint.
+        """
+        self.record_once(lambda s: s.app.after_request_funcs
+            .setdefault(None, []).append(f))
+        return f
+
+    def teardown_request(self, f):
+        """Like :meth:`Flask.teardown_request` but for a blueprint.  This
+        function is only executed when tearing down requests handled by a
+        function of that blueprint.  Teardown request functions are executed
+        when the request context is popped, even when no actual request was
+        performed.
+        """
+        self.record_once(lambda s: s.app.teardown_request_funcs
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def teardown_app_request(self, f):
+        """Like :meth:`Flask.teardown_request` but for a blueprint.  Such a
+        function is executed when tearing down each request, even if outside of
+        the blueprint.
+        """
+        self.record_once(lambda s: s.app.teardown_request_funcs
+            .setdefault(None, []).append(f))
+        return f
+
+    def context_processor(self, f):
+        """Like :meth:`Flask.context_processor` but for a blueprint.  This
+        function is only executed for requests handled by a blueprint.
+        """
+        self.record_once(lambda s: s.app.template_context_processors
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def app_context_processor(self, f):
+        """Like :meth:`Flask.context_processor` but for a blueprint.  Such a
+        function is executed each request, even if outside of the blueprint.
+        """
+        self.record_once(lambda s: s.app.template_context_processors
+            .setdefault(None, []).append(f))
+        return f
+
+    def app_errorhandler(self, code):
+        """Like :meth:`Flask.errorhandler` but for a blueprint.  This
+        handler is used for all requests, even if outside of the blueprint.
+        """
+        def decorator(f):
+            self.record_once(lambda s: s.app.errorhandler(code)(f))
+            return f
+        return decorator
+
+    def url_value_preprocessor(self, f):
+        """Registers a function as URL value preprocessor for this
+        blueprint.  It's called before the view functions are called and
+        can modify the url values provided.
+        """
+        self.record_once(lambda s: s.app.url_value_preprocessors
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def url_defaults(self, f):
+        """Callback function for URL defaults for this blueprint.  It's called
+        with the endpoint and values and should update the values passed
+        in place.
+        """
+        self.record_once(lambda s: s.app.url_default_functions
+            .setdefault(self.name, []).append(f))
+        return f
+
+    def app_url_value_preprocessor(self, f):
+        """Same as :meth:`url_value_preprocessor` but application wide.
+        """
+        self.record_once(lambda s: s.app.url_value_preprocessors
+            .setdefault(None, []).append(f))
+        return f
+
+    def app_url_defaults(self, f):
+        """Same as :meth:`url_defaults` but application wide.
+        """
+        self.record_once(lambda s: s.app.url_default_functions
+            .setdefault(None, []).append(f))
+        return f
+
+    def errorhandler(self, code_or_exception):
+        """Registers an error handler that becomes active for this blueprint
+        only.  Please be aware that routing does not happen local to a
+        blueprint so an error handler for 404 usually is not handled by
+        a blueprint unless it is caused inside a view function.  Another
+        special case is the 500 internal server error which is always looked
+        up from the application.
+
+        Otherwise works as the :meth:`~flask.Flask.errorhandler` decorator
+        of the :class:`~flask.Flask` object.
+        """
+        def decorator(f):
+            self.record_once(lambda s: s.app._register_error_handler(
+                self.name, code_or_exception, f))
+            return f
+        return decorator
+
+    def register_error_handler(self, code_or_exception, f):
+        """Non-decorator version of the :meth:`errorhandler` error attach
+        function, akin to the :meth:`~flask.Flask.register_error_handler`
+        application-wide function of the :class:`~flask.Flask` object but
+        for error handlers limited to this blueprint.
+
+        .. versionadded:: 0.11
+        """
+        self.record_once(lambda s: s.app._register_error_handler(
+            self.name, code_or_exception, f))
diff --git a/python/flask/cli.py b/python/flask/cli.py
new file mode 100644
index 0000000..3eb93b3
--- /dev/null
+++ b/python/flask/cli.py
@@ -0,0 +1,910 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.cli
+    ~~~~~~~~~
+
+    A simple command line application to run flask apps.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from __future__ import print_function
+
+import ast
+import inspect
+import os
+import platform
+import re
+import ssl
+import sys
+import traceback
+from functools import update_wrapper
+from operator import attrgetter
+from threading import Lock, Thread
+
+import click
+from werkzeug.utils import import_string
+
+from . import __version__
+from ._compat import getargspec, iteritems, reraise, text_type
+from .globals import current_app
+from .helpers import get_debug_flag, get_env, get_load_dotenv
+
+try:
+    import dotenv
+except ImportError:
+    dotenv = None
+
+
+class NoAppException(click.UsageError):
+    """Raised if an application cannot be found or loaded."""
+
+
+def find_best_app(script_info, module):
+    """Given a module instance this tries to find the best possible
+    application in the module or raises an exception.
+    """
+    from . import Flask
+
+    # Search for the most common names first.
+    for attr_name in ('app', 'application'):
+        app = getattr(module, attr_name, None)
+
+        if isinstance(app, Flask):
+            return app
+
+    # Otherwise find the only object that is a Flask instance.
+    matches = [
+        v for k, v in iteritems(module.__dict__) if isinstance(v, Flask)
+    ]
+
+    if len(matches) == 1:
+        return matches[0]
+    elif len(matches) > 1:
+        raise NoAppException(
+            'Detected multiple Flask applications in module "{module}". Use '
+            '"FLASK_APP={module}:name" to specify the correct '
+            'one.'.format(module=module.__name__)
+        )
+
+    # Search for app factory functions.
+    for attr_name in ('create_app', 'make_app'):
+        app_factory = getattr(module, attr_name, None)
+
+        if inspect.isfunction(app_factory):
+            try:
+                app = call_factory(script_info, app_factory)
+
+                if isinstance(app, Flask):
+                    return app
+            except TypeError:
+                if not _called_with_wrong_args(app_factory):
+                    raise
+                raise NoAppException(
+                    'Detected factory "{factory}" in module "{module}", but '
+                    'could not call it without arguments. Use '
+                    '"FLASK_APP=\'{module}:{factory}(args)\'" to specify '
+                    'arguments.'.format(
+                        factory=attr_name, module=module.__name__
+                    )
+                )
+
+    raise NoAppException(
+        'Failed to find Flask application or factory in module "{module}". '
+        'Use "FLASK_APP={module}:name to specify one.'.format(
+            module=module.__name__
+        )
+    )
+
+
+def call_factory(script_info, app_factory, arguments=()):
+    """Takes an app factory, a ``script_info` object and  optionally a tuple
+    of arguments. Checks for the existence of a script_info argument and calls
+    the app_factory depending on that and the arguments provided.
+    """
+    args_spec = getargspec(app_factory)
+    arg_names = args_spec.args
+    arg_defaults = args_spec.defaults
+
+    if 'script_info' in arg_names:
+        return app_factory(*arguments, script_info=script_info)
+    elif arguments:
+        return app_factory(*arguments)
+    elif not arguments and len(arg_names) == 1 and arg_defaults is None:
+        return app_factory(script_info)
+
+    return app_factory()
+
+
+def _called_with_wrong_args(factory):
+    """Check whether calling a function raised a ``TypeError`` because
+    the call failed or because something in the factory raised the
+    error.
+
+    :param factory: the factory function that was called
+    :return: true if the call failed
+    """
+    tb = sys.exc_info()[2]
+
+    try:
+        while tb is not None:
+            if tb.tb_frame.f_code is factory.__code__:
+                # in the factory, it was called successfully
+                return False
+
+            tb = tb.tb_next
+
+        # didn't reach the factory
+        return True
+    finally:
+        del tb
+
+
+def find_app_by_string(script_info, module, app_name):
+    """Checks if the given string is a variable name or a function. If it is a
+    function, it checks for specified arguments and whether it takes a
+    ``script_info`` argument and calls the function with the appropriate
+    arguments.
+    """
+    from flask import Flask
+    match = re.match(r'^ *([^ ()]+) *(?:\((.*?) *,? *\))? *$', app_name)
+
+    if not match:
+        raise NoAppException(
+            '"{name}" is not a valid variable name or function '
+            'expression.'.format(name=app_name)
+        )
+
+    name, args = match.groups()
+
+    try:
+        attr = getattr(module, name)
+    except AttributeError as e:
+        raise NoAppException(e.args[0])
+
+    if inspect.isfunction(attr):
+        if args:
+            try:
+                args = ast.literal_eval('({args},)'.format(args=args))
+            except (ValueError, SyntaxError)as e:
+                raise NoAppException(
+                    'Could not parse the arguments in '
+                    '"{app_name}".'.format(e=e, app_name=app_name)
+                )
+        else:
+            args = ()
+
+        try:
+            app = call_factory(script_info, attr, args)
+        except TypeError as e:
+            if not _called_with_wrong_args(attr):
+                raise
+
+            raise NoAppException(
+                '{e}\nThe factory "{app_name}" in module "{module}" could not '
+                'be called with the specified arguments.'.format(
+                    e=e, app_name=app_name, module=module.__name__
+                )
+            )
+    else:
+        app = attr
+
+    if isinstance(app, Flask):
+        return app
+
+    raise NoAppException(
+        'A valid Flask application was not obtained from '
+        '"{module}:{app_name}".'.format(
+            module=module.__name__, app_name=app_name
+        )
+    )
+
+
+def prepare_import(path):
+    """Given a filename this will try to calculate the python path, add it
+    to the search path and return the actual module name that is expected.
+    """
+    path = os.path.realpath(path)
+
+    if os.path.splitext(path)[1] == '.py':
+        path = os.path.splitext(path)[0]
+
+    if os.path.basename(path) == '__init__':
+        path = os.path.dirname(path)
+
+    module_name = []
+
+    # move up until outside package structure (no __init__.py)
+    while True:
+        path, name = os.path.split(path)
+        module_name.append(name)
+
+        if not os.path.exists(os.path.join(path, '__init__.py')):
+            break
+
+    if sys.path[0] != path:
+        sys.path.insert(0, path)
+
+    return '.'.join(module_name[::-1])
+
+
+def locate_app(script_info, module_name, app_name, raise_if_not_found=True):
+    __traceback_hide__ = True
+
+    try:
+        __import__(module_name)
+    except ImportError:
+        # Reraise the ImportError if it occurred within the imported module.
+        # Determine this by checking whether the trace has a depth > 1.
+        if sys.exc_info()[-1].tb_next:
+            raise NoAppException(
+                'While importing "{name}", an ImportError was raised:'
+                '\n\n{tb}'.format(name=module_name, tb=traceback.format_exc())
+            )
+        elif raise_if_not_found:
+            raise NoAppException(
+                'Could not import "{name}".'.format(name=module_name)
+            )
+        else:
+            return
+
+    module = sys.modules[module_name]
+
+    if app_name is None:
+        return find_best_app(script_info, module)
+    else:
+        return find_app_by_string(script_info, module, app_name)
+
+
+def get_version(ctx, param, value):
+    if not value or ctx.resilient_parsing:
+        return
+    import werkzeug
+    message = (
+        'Python %(python)s\n'
+        'Flask %(flask)s\n'
+        'Werkzeug %(werkzeug)s'
+    )
+    click.echo(message % {
+        'python': platform.python_version(),
+        'flask': __version__,
+        'werkzeug': werkzeug.__version__,
+    }, color=ctx.color)
+    ctx.exit()
+
+
+version_option = click.Option(
+    ['--version'],
+    help='Show the flask version',
+    expose_value=False,
+    callback=get_version,
+    is_flag=True,
+    is_eager=True
+)
+
+
+class DispatchingApp(object):
+    """Special application that dispatches to a Flask application which
+    is imported by name in a background thread.  If an error happens
+    it is recorded and shown as part of the WSGI handling which in case
+    of the Werkzeug debugger means that it shows up in the browser.
+    """
+
+    def __init__(self, loader, use_eager_loading=False):
+        self.loader = loader
+        self._app = None
+        self._lock = Lock()
+        self._bg_loading_exc_info = None
+        if use_eager_loading:
+            self._load_unlocked()
+        else:
+            self._load_in_background()
+
+    def _load_in_background(self):
+        def _load_app():
+            __traceback_hide__ = True
+            with self._lock:
+                try:
+                    self._load_unlocked()
+                except Exception:
+                    self._bg_loading_exc_info = sys.exc_info()
+        t = Thread(target=_load_app, args=())
+        t.start()
+
+    def _flush_bg_loading_exception(self):
+        __traceback_hide__ = True
+        exc_info = self._bg_loading_exc_info
+        if exc_info is not None:
+            self._bg_loading_exc_info = None
+            reraise(*exc_info)
+
+    def _load_unlocked(self):
+        __traceback_hide__ = True
+        self._app = rv = self.loader()
+        self._bg_loading_exc_info = None
+        return rv
+
+    def __call__(self, environ, start_response):
+        __traceback_hide__ = True
+        if self._app is not None:
+            return self._app(environ, start_response)
+        self._flush_bg_loading_exception()
+        with self._lock:
+            if self._app is not None:
+                rv = self._app
+            else:
+                rv = self._load_unlocked()
+            return rv(environ, start_response)
+
+
+class ScriptInfo(object):
+    """Helper object to deal with Flask applications.  This is usually not
+    necessary to interface with as it's used internally in the dispatching
+    to click.  In future versions of Flask this object will most likely play
+    a bigger role.  Typically it's created automatically by the
+    :class:`FlaskGroup` but you can also manually create it and pass it
+    onwards as click object.
+    """
+
+    def __init__(self, app_import_path=None, create_app=None,
+                 set_debug_flag=True):
+        #: Optionally the import path for the Flask application.
+        self.app_import_path = app_import_path or os.environ.get('FLASK_APP')
+        #: Optionally a function that is passed the script info to create
+        #: the instance of the application.
+        self.create_app = create_app
+        #: A dictionary with arbitrary data that can be associated with
+        #: this script info.
+        self.data = {}
+        self.set_debug_flag = set_debug_flag
+        self._loaded_app = None
+
+    def load_app(self):
+        """Loads the Flask app (if not yet loaded) and returns it.  Calling
+        this multiple times will just result in the already loaded app to
+        be returned.
+        """
+        __traceback_hide__ = True
+
+        if self._loaded_app is not None:
+            return self._loaded_app
+
+        app = None
+
+        if self.create_app is not None:
+            app = call_factory(self, self.create_app)
+        else:
+            if self.app_import_path:
+                path, name = (re.split(r':(?![\\/])', self.app_import_path, 1) + [None])[:2]
+                import_name = prepare_import(path)
+                app = locate_app(self, import_name, name)
+            else:
+                for path in ('wsgi.py', 'app.py'):
+                    import_name = prepare_import(path)
+                    app = locate_app(self, import_name, None,
+                                     raise_if_not_found=False)
+
+                    if app:
+                        break
+
+        if not app:
+            raise NoAppException(
+                'Could not locate a Flask application. You did not provide '
+                'the "FLASK_APP" environment variable, and a "wsgi.py" or '
+                '"app.py" module was not found in the current directory.'
+            )
+
+        if self.set_debug_flag:
+            # Update the app's debug flag through the descriptor so that
+            # other values repopulate as well.
+            app.debug = get_debug_flag()
+
+        self._loaded_app = app
+        return app
+
+
+pass_script_info = click.make_pass_decorator(ScriptInfo, ensure=True)
+
+
+def with_appcontext(f):
+    """Wraps a callback so that it's guaranteed to be executed with the
+    script's application context.  If callbacks are registered directly
+    to the ``app.cli`` object then they are wrapped with this function
+    by default unless it's disabled.
+    """
+    @click.pass_context
+    def decorator(__ctx, *args, **kwargs):
+        with __ctx.ensure_object(ScriptInfo).load_app().app_context():
+            return __ctx.invoke(f, *args, **kwargs)
+    return update_wrapper(decorator, f)
+
+
+class AppGroup(click.Group):
+    """This works similar to a regular click :class:`~click.Group` but it
+    changes the behavior of the :meth:`command` decorator so that it
+    automatically wraps the functions in :func:`with_appcontext`.
+
+    Not to be confused with :class:`FlaskGroup`.
+    """
+
+    def command(self, *args, **kwargs):
+        """This works exactly like the method of the same name on a regular
+        :class:`click.Group` but it wraps callbacks in :func:`with_appcontext`
+        unless it's disabled by passing ``with_appcontext=False``.
+        """
+        wrap_for_ctx = kwargs.pop('with_appcontext', True)
+        def decorator(f):
+            if wrap_for_ctx:
+                f = with_appcontext(f)
+            return click.Group.command(self, *args, **kwargs)(f)
+        return decorator
+
+    def group(self, *args, **kwargs):
+        """This works exactly like the method of the same name on a regular
+        :class:`click.Group` but it defaults the group class to
+        :class:`AppGroup`.
+        """
+        kwargs.setdefault('cls', AppGroup)
+        return click.Group.group(self, *args, **kwargs)
+
+
+class FlaskGroup(AppGroup):
+    """Special subclass of the :class:`AppGroup` group that supports
+    loading more commands from the configured Flask app.  Normally a
+    developer does not have to interface with this class but there are
+    some very advanced use cases for which it makes sense to create an
+    instance of this.
+
+    For information as of why this is useful see :ref:`custom-scripts`.
+
+    :param add_default_commands: if this is True then the default run and
+        shell commands wil be added.
+    :param add_version_option: adds the ``--version`` option.
+    :param create_app: an optional callback that is passed the script info and
+        returns the loaded app.
+    :param load_dotenv: Load the nearest :file:`.env` and :file:`.flaskenv`
+        files to set environment variables. Will also change the working
+        directory to the directory containing the first file found.
+    :param set_debug_flag: Set the app's debug flag based on the active
+        environment
+
+    .. versionchanged:: 1.0
+        If installed, python-dotenv will be used to load environment variables
+        from :file:`.env` and :file:`.flaskenv` files.
+    """
+
+    def __init__(self, add_default_commands=True, create_app=None,
+                 add_version_option=True, load_dotenv=True,
+                 set_debug_flag=True, **extra):
+        params = list(extra.pop('params', None) or ())
+
+        if add_version_option:
+            params.append(version_option)
+
+        AppGroup.__init__(self, params=params, **extra)
+        self.create_app = create_app
+        self.load_dotenv = load_dotenv
+        self.set_debug_flag = set_debug_flag
+
+        if add_default_commands:
+            self.add_command(run_command)
+            self.add_command(shell_command)
+            self.add_command(routes_command)
+
+        self._loaded_plugin_commands = False
+
+    def _load_plugin_commands(self):
+        if self._loaded_plugin_commands:
+            return
+        try:
+            import pkg_resources
+        except ImportError:
+            self._loaded_plugin_commands = True
+            return
+
+        for ep in pkg_resources.iter_entry_points('flask.commands'):
+            self.add_command(ep.load(), ep.name)
+        self._loaded_plugin_commands = True
+
+    def get_command(self, ctx, name):
+        self._load_plugin_commands()
+
+        # We load built-in commands first as these should always be the
+        # same no matter what the app does.  If the app does want to
+        # override this it needs to make a custom instance of this group
+        # and not attach the default commands.
+        #
+        # This also means that the script stays functional in case the
+        # application completely fails.
+        rv = AppGroup.get_command(self, ctx, name)
+        if rv is not None:
+            return rv
+
+        info = ctx.ensure_object(ScriptInfo)
+        try:
+            rv = info.load_app().cli.get_command(ctx, name)
+            if rv is not None:
+                return rv
+        except NoAppException:
+            pass
+
+    def list_commands(self, ctx):
+        self._load_plugin_commands()
+
+        # The commands available is the list of both the application (if
+        # available) plus the builtin commands.
+        rv = set(click.Group.list_commands(self, ctx))
+        info = ctx.ensure_object(ScriptInfo)
+        try:
+            rv.update(info.load_app().cli.list_commands(ctx))
+        except Exception:
+            # Here we intentionally swallow all exceptions as we don't
+            # want the help page to break if the app does not exist.
+            # If someone attempts to use the command we try to create
+            # the app again and this will give us the error.
+            # However, we will not do so silently because that would confuse
+            # users.
+            traceback.print_exc()
+        return sorted(rv)
+
+    def main(self, *args, **kwargs):
+        # Set a global flag that indicates that we were invoked from the
+        # command line interface. This is detected by Flask.run to make the
+        # call into a no-op. This is necessary to avoid ugly errors when the
+        # script that is loaded here also attempts to start a server.
+        os.environ['FLASK_RUN_FROM_CLI'] = 'true'
+
+        if get_load_dotenv(self.load_dotenv):
+            load_dotenv()
+
+        obj = kwargs.get('obj')
+
+        if obj is None:
+            obj = ScriptInfo(create_app=self.create_app,
+                             set_debug_flag=self.set_debug_flag)
+
+        kwargs['obj'] = obj
+        kwargs.setdefault('auto_envvar_prefix', 'FLASK')
+        return super(FlaskGroup, self).main(*args, **kwargs)
+
+
+def _path_is_ancestor(path, other):
+    """Take ``other`` and remove the length of ``path`` from it. Then join it
+    to ``path``. If it is the original value, ``path`` is an ancestor of
+    ``other``."""
+    return os.path.join(path, other[len(path):].lstrip(os.sep)) == other
+
+
+def load_dotenv(path=None):
+    """Load "dotenv" files in order of precedence to set environment variables.
+
+    If an env var is already set it is not overwritten, so earlier files in the
+    list are preferred over later files.
+
+    Changes the current working directory to the location of the first file
+    found, with the assumption that it is in the top level project directory
+    and will be where the Python path should import local packages from.
+
+    This is a no-op if `python-dotenv`_ is not installed.
+
+    .. _python-dotenv: https://github.com/theskumar/python-dotenv#readme
+
+    :param path: Load the file at this location instead of searching.
+    :return: ``True`` if a file was loaded.
+
+    .. versionadded:: 1.0
+    """
+    if dotenv is None:
+        if path or os.path.exists('.env') or os.path.exists('.flaskenv'):
+            click.secho(
+                ' * Tip: There are .env files present.'
+                ' Do "pip install python-dotenv" to use them.',
+                fg='yellow')
+        return
+
+    if path is not None:
+        return dotenv.load_dotenv(path)
+
+    new_dir = None
+
+    for name in ('.env', '.flaskenv'):
+        path = dotenv.find_dotenv(name, usecwd=True)
+
+        if not path:
+            continue
+
+        if new_dir is None:
+            new_dir = os.path.dirname(path)
+
+        dotenv.load_dotenv(path)
+
+    if new_dir and os.getcwd() != new_dir:
+        os.chdir(new_dir)
+
+    return new_dir is not None  # at least one file was located and loaded
+
+
+def show_server_banner(env, debug, app_import_path, eager_loading):
+    """Show extra startup messages the first time the server is run,
+    ignoring the reloader.
+    """
+    if os.environ.get('WERKZEUG_RUN_MAIN') == 'true':
+        return
+
+    if app_import_path is not None:
+        message = ' * Serving Flask app "{0}"'.format(app_import_path)
+
+        if not eager_loading:
+            message += ' (lazy loading)'
+
+        click.echo(message)
+
+    click.echo(' * Environment: {0}'.format(env))
+
+    if env == 'production':
+        click.secho(
+            '   WARNING: This is a development server. '
+            'Do not use it in a production deployment.', fg='red')
+        click.secho('   Use a production WSGI server instead.', dim=True)
+
+    if debug is not None:
+        click.echo(' * Debug mode: {0}'.format('on' if debug else 'off'))
+
+
+class CertParamType(click.ParamType):
+    """Click option type for the ``--cert`` option. Allows either an
+    existing file, the string ``'adhoc'``, or an import for a
+    :class:`~ssl.SSLContext` object.
+    """
+
+    name = 'path'
+
+    def __init__(self):
+        self.path_type = click.Path(
+            exists=True, dir_okay=False, resolve_path=True)
+
+    def convert(self, value, param, ctx):
+        try:
+            return self.path_type(value, param, ctx)
+        except click.BadParameter:
+            value = click.STRING(value, param, ctx).lower()
+
+            if value == 'adhoc':
+                try:
+                    import OpenSSL
+                except ImportError:
+                    raise click.BadParameter(
+                        'Using ad-hoc certificates requires pyOpenSSL.',
+                        ctx, param)
+
+                return value
+
+            obj = import_string(value, silent=True)
+
+            if sys.version_info < (2, 7, 9):
+                if obj:
+                    return obj
+            else:
+                if isinstance(obj, ssl.SSLContext):
+                    return obj
+
+            raise
+
+
+def _validate_key(ctx, param, value):
+    """The ``--key`` option must be specified when ``--cert`` is a file.
+    Modifies the ``cert`` param to be a ``(cert, key)`` pair if needed.
+    """
+    cert = ctx.params.get('cert')
+    is_adhoc = cert == 'adhoc'
+
+    if sys.version_info < (2, 7, 9):
+        is_context = cert and not isinstance(cert, (text_type, bytes))
+    else:
+        is_context = isinstance(cert, ssl.SSLContext)
+
+    if value is not None:
+        if is_adhoc:
+            raise click.BadParameter(
+                'When "--cert" is "adhoc", "--key" is not used.',
+                ctx, param)
+
+        if is_context:
+            raise click.BadParameter(
+                'When "--cert" is an SSLContext object, "--key is not used.',
+                ctx, param)
+
+        if not cert:
+            raise click.BadParameter(
+                '"--cert" must also be specified.',
+                ctx, param)
+
+        ctx.params['cert'] = cert, value
+
+    else:
+        if cert and not (is_adhoc or is_context):
+            raise click.BadParameter(
+                'Required when using "--cert".',
+                ctx, param)
+
+    return value
+
+
+@click.command('run', short_help='Run a development server.')
+@click.option('--host', '-h', default='127.0.0.1',
+              help='The interface to bind to.')
+@click.option('--port', '-p', default=5000,
+              help='The port to bind to.')
+@click.option('--cert', type=CertParamType(),
+              help='Specify a certificate file to use HTTPS.')
+@click.option('--key',
+              type=click.Path(exists=True, dir_okay=False, resolve_path=True),
+              callback=_validate_key, expose_value=False,
+              help='The key file to use when specifying a certificate.')
+@click.option('--reload/--no-reload', default=None,
+              help='Enable or disable the reloader. By default the reloader '
+              'is active if debug is enabled.')
+@click.option('--debugger/--no-debugger', default=None,
+              help='Enable or disable the debugger. By default the debugger '
+              'is active if debug is enabled.')
+@click.option('--eager-loading/--lazy-loader', default=None,
+              help='Enable or disable eager loading. By default eager '
+              'loading is enabled if the reloader is disabled.')
+@click.option('--with-threads/--without-threads', default=True,
+              help='Enable or disable multithreading.')
+@pass_script_info
+def run_command(info, host, port, reload, debugger, eager_loading,
+                with_threads, cert):
+    """Run a local development server.
+
+    This server is for development purposes only. It does not provide
+    the stability, security, or performance of production WSGI servers.
+
+    The reloader and debugger are enabled by default if
+    FLASK_ENV=development or FLASK_DEBUG=1.
+    """
+    debug = get_debug_flag()
+
+    if reload is None:
+        reload = debug
+
+    if debugger is None:
+        debugger = debug
+
+    if eager_loading is None:
+        eager_loading = not reload
+
+    show_server_banner(get_env(), debug, info.app_import_path, eager_loading)
+    app = DispatchingApp(info.load_app, use_eager_loading=eager_loading)
+
+    from werkzeug.serving import run_simple
+    run_simple(host, port, app, use_reloader=reload, use_debugger=debugger,
+               threaded=with_threads, ssl_context=cert)
+
+
+@click.command('shell', short_help='Run a shell in the app context.')
+@with_appcontext
+def shell_command():
+    """Run an interactive Python shell in the context of a given
+    Flask application.  The application will populate the default
+    namespace of this shell according to it's configuration.
+
+    This is useful for executing small snippets of management code
+    without having to manually configure the application.
+    """
+    import code
+    from flask.globals import _app_ctx_stack
+    app = _app_ctx_stack.top.app
+    banner = 'Python %s on %s\nApp: %s [%s]\nInstance: %s' % (
+        sys.version,
+        sys.platform,
+        app.import_name,
+        app.env,
+        app.instance_path,
+    )
+    ctx = {}
+
+    # Support the regular Python interpreter startup script if someone
+    # is using it.
+    startup = os.environ.get('PYTHONSTARTUP')
+    if startup and os.path.isfile(startup):
+        with open(startup, 'r') as f:
+            eval(compile(f.read(), startup, 'exec'), ctx)
+
+    ctx.update(app.make_shell_context())
+
+    code.interact(banner=banner, local=ctx)
+
+
+@click.command('routes', short_help='Show the routes for the app.')
+@click.option(
+    '--sort', '-s',
+    type=click.Choice(('endpoint', 'methods', 'rule', 'match')),
+    default='endpoint',
+    help=(
+        'Method to sort routes by. "match" is the order that Flask will match '
+        'routes when dispatching a request.'
+    )
+)
+@click.option(
+    '--all-methods',
+    is_flag=True,
+    help="Show HEAD and OPTIONS methods."
+)
+@with_appcontext
+def routes_command(sort, all_methods):
+    """Show all registered routes with endpoints and methods."""
+
+    rules = list(current_app.url_map.iter_rules())
+    if not rules:
+        click.echo('No routes were registered.')
+        return
+
+    ignored_methods = set(() if all_methods else ('HEAD', 'OPTIONS'))
+
+    if sort in ('endpoint', 'rule'):
+        rules = sorted(rules, key=attrgetter(sort))
+    elif sort == 'methods':
+        rules = sorted(rules, key=lambda rule: sorted(rule.methods))
+
+    rule_methods = [
+        ', '.join(sorted(rule.methods - ignored_methods)) for rule in rules
+    ]
+
+    headers = ('Endpoint', 'Methods', 'Rule')
+    widths = (
+        max(len(rule.endpoint) for rule in rules),
+        max(len(methods) for methods in rule_methods),
+        max(len(rule.rule) for rule in rules),
+    )
+    widths = [max(len(h), w) for h, w in zip(headers, widths)]
+    row = '{{0:<{0}}}  {{1:<{1}}}  {{2:<{2}}}'.format(*widths)
+
+    click.echo(row.format(*headers).strip())
+    click.echo(row.format(*('-' * width for width in widths)))
+
+    for rule, methods in zip(rules, rule_methods):
+        click.echo(row.format(rule.endpoint, methods, rule.rule).rstrip())
+
+
+cli = FlaskGroup(help="""\
+A general utility script for Flask applications.
+
+Provides commands from Flask, extensions, and the application. Loads the
+application defined in the FLASK_APP environment variable, or from a wsgi.py
+file. Setting the FLASK_ENV environment variable to 'development' will enable
+debug mode.
+
+\b
+  {prefix}{cmd} FLASK_APP=hello.py
+  {prefix}{cmd} FLASK_ENV=development
+  {prefix}flask run
+""".format(
+    cmd='export' if os.name == 'posix' else 'set',
+    prefix='$ ' if os.name == 'posix' else '> '
+))
+
+
+def main(as_module=False):
+    args = sys.argv[1:]
+
+    if as_module:
+        this_module = 'flask'
+
+        if sys.version_info < (2, 7):
+            this_module += '.cli'
+
+        name = 'python -m ' + this_module
+
+        # Python rewrites "python -m flask" to the path to the file in argv.
+        # Restore the original command so that the reloader works.
+        sys.argv = ['-m', this_module] + args
+    else:
+        name = None
+
+    cli.main(args=args, prog_name=name)
+
+
+if __name__ == '__main__':
+    main(as_module=True)
diff --git a/python/flask/config.py b/python/flask/config.py
new file mode 100644
index 0000000..a5475ed
--- /dev/null
+++ b/python/flask/config.py
@@ -0,0 +1,269 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.config
+    ~~~~~~~~~~~~
+
+    Implements the configuration related objects.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import os
+import types
+import errno
+
+from werkzeug.utils import import_string
+from ._compat import string_types, iteritems
+from . import json
+
+
+class ConfigAttribute(object):
+    """Makes an attribute forward to the config"""
+
+    def __init__(self, name, get_converter=None):
+        self.__name__ = name
+        self.get_converter = get_converter
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        rv = obj.config[self.__name__]
+        if self.get_converter is not None:
+            rv = self.get_converter(rv)
+        return rv
+
+    def __set__(self, obj, value):
+        obj.config[self.__name__] = value
+
+
+class Config(dict):
+    """Works exactly like a dict but provides ways to fill it from files
+    or special dictionaries.  There are two common patterns to populate the
+    config.
+
+    Either you can fill the config from a config file::
+
+        app.config.from_pyfile('yourconfig.cfg')
+
+    Or alternatively you can define the configuration options in the
+    module that calls :meth:`from_object` or provide an import path to
+    a module that should be loaded.  It is also possible to tell it to
+    use the same module and with that provide the configuration values
+    just before the call::
+
+        DEBUG = True
+        SECRET_KEY = 'development key'
+        app.config.from_object(__name__)
+
+    In both cases (loading from any Python file or loading from modules),
+    only uppercase keys are added to the config.  This makes it possible to use
+    lowercase values in the config file for temporary values that are not added
+    to the config or to define the config keys in the same file that implements
+    the application.
+
+    Probably the most interesting way to load configurations is from an
+    environment variable pointing to a file::
+
+        app.config.from_envvar('YOURAPPLICATION_SETTINGS')
+
+    In this case before launching the application you have to set this
+    environment variable to the file you want to use.  On Linux and OS X
+    use the export statement::
+
+        export YOURAPPLICATION_SETTINGS='/path/to/config/file'
+
+    On windows use `set` instead.
+
+    :param root_path: path to which files are read relative from.  When the
+                      config object is created by the application, this is
+                      the application's :attr:`~flask.Flask.root_path`.
+    :param defaults: an optional dictionary of default values
+    """
+
+    def __init__(self, root_path, defaults=None):
+        dict.__init__(self, defaults or {})
+        self.root_path = root_path
+
+    def from_envvar(self, variable_name, silent=False):
+        """Loads a configuration from an environment variable pointing to
+        a configuration file.  This is basically just a shortcut with nicer
+        error messages for this line of code::
+
+            app.config.from_pyfile(os.environ['YOURAPPLICATION_SETTINGS'])
+
+        :param variable_name: name of the environment variable
+        :param silent: set to ``True`` if you want silent failure for missing
+                       files.
+        :return: bool. ``True`` if able to load config, ``False`` otherwise.
+        """
+        rv = os.environ.get(variable_name)
+        if not rv:
+            if silent:
+                return False
+            raise RuntimeError('The environment variable %r is not set '
+                               'and as such configuration could not be '
+                               'loaded.  Set this variable and make it '
+                               'point to a configuration file' %
+                               variable_name)
+        return self.from_pyfile(rv, silent=silent)
+
+    def from_pyfile(self, filename, silent=False):
+        """Updates the values in the config from a Python file.  This function
+        behaves as if the file was imported as module with the
+        :meth:`from_object` function.
+
+        :param filename: the filename of the config.  This can either be an
+                         absolute filename or a filename relative to the
+                         root path.
+        :param silent: set to ``True`` if you want silent failure for missing
+                       files.
+
+        .. versionadded:: 0.7
+           `silent` parameter.
+        """
+        filename = os.path.join(self.root_path, filename)
+        d = types.ModuleType('config')
+        d.__file__ = filename
+        try:
+            with open(filename, mode='rb') as config_file:
+                exec(compile(config_file.read(), filename, 'exec'), d.__dict__)
+        except IOError as e:
+            if silent and e.errno in (
+                errno.ENOENT, errno.EISDIR, errno.ENOTDIR
+            ):
+                return False
+            e.strerror = 'Unable to load configuration file (%s)' % e.strerror
+            raise
+        self.from_object(d)
+        return True
+
+    def from_object(self, obj):
+        """Updates the values from the given object.  An object can be of one
+        of the following two types:
+
+        -   a string: in this case the object with that name will be imported
+        -   an actual object reference: that object is used directly
+
+        Objects are usually either modules or classes. :meth:`from_object`
+        loads only the uppercase attributes of the module/class. A ``dict``
+        object will not work with :meth:`from_object` because the keys of a
+        ``dict`` are not attributes of the ``dict`` class.
+
+        Example of module-based configuration::
+
+            app.config.from_object('yourapplication.default_config')
+            from yourapplication import default_config
+            app.config.from_object(default_config)
+
+        Nothing is done to the object before loading. If the object is a
+        class and has ``@property`` attributes, it needs to be
+        instantiated before being passed to this method.
+
+        You should not use this function to load the actual configuration but
+        rather configuration defaults.  The actual config should be loaded
+        with :meth:`from_pyfile` and ideally from a location not within the
+        package because the package might be installed system wide.
+
+        See :ref:`config-dev-prod` for an example of class-based configuration
+        using :meth:`from_object`.
+
+        :param obj: an import name or object
+        """
+        if isinstance(obj, string_types):
+            obj = import_string(obj)
+        for key in dir(obj):
+            if key.isupper():
+                self[key] = getattr(obj, key)
+
+    def from_json(self, filename, silent=False):
+        """Updates the values in the config from a JSON file. This function
+        behaves as if the JSON object was a dictionary and passed to the
+        :meth:`from_mapping` function.
+
+        :param filename: the filename of the JSON file.  This can either be an
+                         absolute filename or a filename relative to the
+                         root path.
+        :param silent: set to ``True`` if you want silent failure for missing
+                       files.
+
+        .. versionadded:: 0.11
+        """
+        filename = os.path.join(self.root_path, filename)
+
+        try:
+            with open(filename) as json_file:
+                obj = json.loads(json_file.read())
+        except IOError as e:
+            if silent and e.errno in (errno.ENOENT, errno.EISDIR):
+                return False
+            e.strerror = 'Unable to load configuration file (%s)' % e.strerror
+            raise
+        return self.from_mapping(obj)
+
+    def from_mapping(self, *mapping, **kwargs):
+        """Updates the config like :meth:`update` ignoring items with non-upper
+        keys.
+
+        .. versionadded:: 0.11
+        """
+        mappings = []
+        if len(mapping) == 1:
+            if hasattr(mapping[0], 'items'):
+                mappings.append(mapping[0].items())
+            else:
+                mappings.append(mapping[0])
+        elif len(mapping) > 1:
+            raise TypeError(
+                'expected at most 1 positional argument, got %d' % len(mapping)
+            )
+        mappings.append(kwargs.items())
+        for mapping in mappings:
+            for (key, value) in mapping:
+                if key.isupper():
+                    self[key] = value
+        return True
+
+    def get_namespace(self, namespace, lowercase=True, trim_namespace=True):
+        """Returns a dictionary containing a subset of configuration options
+        that match the specified namespace/prefix. Example usage::
+
+            app.config['IMAGE_STORE_TYPE'] = 'fs'
+            app.config['IMAGE_STORE_PATH'] = '/var/app/images'
+            app.config['IMAGE_STORE_BASE_URL'] = 'http://img.website.com'
+            image_store_config = app.config.get_namespace('IMAGE_STORE_')
+
+        The resulting dictionary `image_store_config` would look like::
+
+            {
+                'type': 'fs',
+                'path': '/var/app/images',
+                'base_url': 'http://img.website.com'
+            }
+
+        This is often useful when configuration options map directly to
+        keyword arguments in functions or class constructors.
+
+        :param namespace: a configuration namespace
+        :param lowercase: a flag indicating if the keys of the resulting
+                          dictionary should be lowercase
+        :param trim_namespace: a flag indicating if the keys of the resulting
+                          dictionary should not include the namespace
+
+        .. versionadded:: 0.11
+        """
+        rv = {}
+        for k, v in iteritems(self):
+            if not k.startswith(namespace):
+                continue
+            if trim_namespace:
+                key = k[len(namespace):]
+            else:
+                key = k
+            if lowercase:
+                key = key.lower()
+            rv[key] = v
+        return rv
+
+    def __repr__(self):
+        return '<%s %s>' % (self.__class__.__name__, dict.__repr__(self))
diff --git a/python/flask/ctx.py b/python/flask/ctx.py
new file mode 100644
index 0000000..ec8e787
--- /dev/null
+++ b/python/flask/ctx.py
@@ -0,0 +1,457 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.ctx
+    ~~~~~~~~~
+
+    Implements the objects required to keep the context.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import sys
+from functools import update_wrapper
+
+from werkzeug.exceptions import HTTPException
+
+from .globals import _request_ctx_stack, _app_ctx_stack
+from .signals import appcontext_pushed, appcontext_popped
+from ._compat import BROKEN_PYPY_CTXMGR_EXIT, reraise
+
+
+# a singleton sentinel value for parameter defaults
+_sentinel = object()
+
+
+class _AppCtxGlobals(object):
+    """A plain object. Used as a namespace for storing data during an
+    application context.
+
+    Creating an app context automatically creates this object, which is
+    made available as the :data:`g` proxy.
+
+    .. describe:: 'key' in g
+
+        Check whether an attribute is present.
+
+        .. versionadded:: 0.10
+
+    .. describe:: iter(g)
+
+        Return an iterator over the attribute names.
+
+        .. versionadded:: 0.10
+    """
+
+    def get(self, name, default=None):
+        """Get an attribute by name, or a default value. Like
+        :meth:`dict.get`.
+
+        :param name: Name of attribute to get.
+        :param default: Value to return if the attribute is not present.
+
+        .. versionadded:: 0.10
+        """
+        return self.__dict__.get(name, default)
+
+    def pop(self, name, default=_sentinel):
+        """Get and remove an attribute by name. Like :meth:`dict.pop`.
+
+        :param name: Name of attribute to pop.
+        :param default: Value to return if the attribute is not present,
+            instead of raise a ``KeyError``.
+
+        .. versionadded:: 0.11
+        """
+        if default is _sentinel:
+            return self.__dict__.pop(name)
+        else:
+            return self.__dict__.pop(name, default)
+
+    def setdefault(self, name, default=None):
+        """Get the value of an attribute if it is present, otherwise
+        set and return a default value. Like :meth:`dict.setdefault`.
+
+        :param name: Name of attribute to get.
+        :param: default: Value to set and return if the attribute is not
+            present.
+
+        .. versionadded:: 0.11
+        """
+        return self.__dict__.setdefault(name, default)
+
+    def __contains__(self, item):
+        return item in self.__dict__
+
+    def __iter__(self):
+        return iter(self.__dict__)
+
+    def __repr__(self):
+        top = _app_ctx_stack.top
+        if top is not None:
+            return '<flask.g of %r>' % top.app.name
+        return object.__repr__(self)
+
+
+def after_this_request(f):
+    """Executes a function after this request.  This is useful to modify
+    response objects.  The function is passed the response object and has
+    to return the same or a new one.
+
+    Example::
+
+        @app.route('/')
+        def index():
+            @after_this_request
+            def add_header(response):
+                response.headers['X-Foo'] = 'Parachute'
+                return response
+            return 'Hello World!'
+
+    This is more useful if a function other than the view function wants to
+    modify a response.  For instance think of a decorator that wants to add
+    some headers without converting the return value into a response object.
+
+    .. versionadded:: 0.9
+    """
+    _request_ctx_stack.top._after_request_functions.append(f)
+    return f
+
+
+def copy_current_request_context(f):
+    """A helper function that decorates a function to retain the current
+    request context.  This is useful when working with greenlets.  The moment
+    the function is decorated a copy of the request context is created and
+    then pushed when the function is called.
+
+    Example::
+
+        import gevent
+        from flask import copy_current_request_context
+
+        @app.route('/')
+        def index():
+            @copy_current_request_context
+            def do_some_work():
+                # do some work here, it can access flask.request like you
+                # would otherwise in the view function.
+                ...
+            gevent.spawn(do_some_work)
+            return 'Regular response'
+
+    .. versionadded:: 0.10
+    """
+    top = _request_ctx_stack.top
+    if top is None:
+        raise RuntimeError('This decorator can only be used at local scopes '
+            'when a request context is on the stack.  For instance within '
+            'view functions.')
+    reqctx = top.copy()
+    def wrapper(*args, **kwargs):
+        with reqctx:
+            return f(*args, **kwargs)
+    return update_wrapper(wrapper, f)
+
+
+def has_request_context():
+    """If you have code that wants to test if a request context is there or
+    not this function can be used.  For instance, you may want to take advantage
+    of request information if the request object is available, but fail
+    silently if it is unavailable.
+
+    ::
+
+        class User(db.Model):
+
+            def __init__(self, username, remote_addr=None):
+                self.username = username
+                if remote_addr is None and has_request_context():
+                    remote_addr = request.remote_addr
+                self.remote_addr = remote_addr
+
+    Alternatively you can also just test any of the context bound objects
+    (such as :class:`request` or :class:`g`) for truthness::
+
+        class User(db.Model):
+
+            def __init__(self, username, remote_addr=None):
+                self.username = username
+                if remote_addr is None and request:
+                    remote_addr = request.remote_addr
+                self.remote_addr = remote_addr
+
+    .. versionadded:: 0.7
+    """
+    return _request_ctx_stack.top is not None
+
+
+def has_app_context():
+    """Works like :func:`has_request_context` but for the application
+    context.  You can also just do a boolean check on the
+    :data:`current_app` object instead.
+
+    .. versionadded:: 0.9
+    """
+    return _app_ctx_stack.top is not None
+
+
+class AppContext(object):
+    """The application context binds an application object implicitly
+    to the current thread or greenlet, similar to how the
+    :class:`RequestContext` binds request information.  The application
+    context is also implicitly created if a request context is created
+    but the application is not on top of the individual application
+    context.
+    """
+
+    def __init__(self, app):
+        self.app = app
+        self.url_adapter = app.create_url_adapter(None)
+        self.g = app.app_ctx_globals_class()
+
+        # Like request context, app contexts can be pushed multiple times
+        # but there a basic "refcount" is enough to track them.
+        self._refcnt = 0
+
+    def push(self):
+        """Binds the app context to the current context."""
+        self._refcnt += 1
+        if hasattr(sys, 'exc_clear'):
+            sys.exc_clear()
+        _app_ctx_stack.push(self)
+        appcontext_pushed.send(self.app)
+
+    def pop(self, exc=_sentinel):
+        """Pops the app context."""
+        try:
+            self._refcnt -= 1
+            if self._refcnt <= 0:
+                if exc is _sentinel:
+                    exc = sys.exc_info()[1]
+                self.app.do_teardown_appcontext(exc)
+        finally:
+            rv = _app_ctx_stack.pop()
+        assert rv is self, 'Popped wrong app context.  (%r instead of %r)' \
+            % (rv, self)
+        appcontext_popped.send(self.app)
+
+    def __enter__(self):
+        self.push()
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        self.pop(exc_value)
+
+        if BROKEN_PYPY_CTXMGR_EXIT and exc_type is not None:
+            reraise(exc_type, exc_value, tb)
+
+
+class RequestContext(object):
+    """The request context contains all request relevant information.  It is
+    created at the beginning of the request and pushed to the
+    `_request_ctx_stack` and removed at the end of it.  It will create the
+    URL adapter and request object for the WSGI environment provided.
+
+    Do not attempt to use this class directly, instead use
+    :meth:`~flask.Flask.test_request_context` and
+    :meth:`~flask.Flask.request_context` to create this object.
+
+    When the request context is popped, it will evaluate all the
+    functions registered on the application for teardown execution
+    (:meth:`~flask.Flask.teardown_request`).
+
+    The request context is automatically popped at the end of the request
+    for you.  In debug mode the request context is kept around if
+    exceptions happen so that interactive debuggers have a chance to
+    introspect the data.  With 0.4 this can also be forced for requests
+    that did not fail and outside of ``DEBUG`` mode.  By setting
+    ``'flask._preserve_context'`` to ``True`` on the WSGI environment the
+    context will not pop itself at the end of the request.  This is used by
+    the :meth:`~flask.Flask.test_client` for example to implement the
+    deferred cleanup functionality.
+
+    You might find this helpful for unittests where you need the
+    information from the context local around for a little longer.  Make
+    sure to properly :meth:`~werkzeug.LocalStack.pop` the stack yourself in
+    that situation, otherwise your unittests will leak memory.
+    """
+
+    def __init__(self, app, environ, request=None):
+        self.app = app
+        if request is None:
+            request = app.request_class(environ)
+        self.request = request
+        self.url_adapter = app.create_url_adapter(self.request)
+        self.flashes = None
+        self.session = None
+
+        # Request contexts can be pushed multiple times and interleaved with
+        # other request contexts.  Now only if the last level is popped we
+        # get rid of them.  Additionally if an application context is missing
+        # one is created implicitly so for each level we add this information
+        self._implicit_app_ctx_stack = []
+
+        # indicator if the context was preserved.  Next time another context
+        # is pushed the preserved context is popped.
+        self.preserved = False
+
+        # remembers the exception for pop if there is one in case the context
+        # preservation kicks in.
+        self._preserved_exc = None
+
+        # Functions that should be executed after the request on the response
+        # object.  These will be called before the regular "after_request"
+        # functions.
+        self._after_request_functions = []
+
+        self.match_request()
+
+    def _get_g(self):
+        return _app_ctx_stack.top.g
+    def _set_g(self, value):
+        _app_ctx_stack.top.g = value
+    g = property(_get_g, _set_g)
+    del _get_g, _set_g
+
+    def copy(self):
+        """Creates a copy of this request context with the same request object.
+        This can be used to move a request context to a different greenlet.
+        Because the actual request object is the same this cannot be used to
+        move a request context to a different thread unless access to the
+        request object is locked.
+
+        .. versionadded:: 0.10
+        """
+        return self.__class__(self.app,
+            environ=self.request.environ,
+            request=self.request
+        )
+
+    def match_request(self):
+        """Can be overridden by a subclass to hook into the matching
+        of the request.
+        """
+        try:
+            url_rule, self.request.view_args = \
+                self.url_adapter.match(return_rule=True)
+            self.request.url_rule = url_rule
+        except HTTPException as e:
+            self.request.routing_exception = e
+
+    def push(self):
+        """Binds the request context to the current context."""
+        # If an exception occurs in debug mode or if context preservation is
+        # activated under exception situations exactly one context stays
+        # on the stack.  The rationale is that you want to access that
+        # information under debug situations.  However if someone forgets to
+        # pop that context again we want to make sure that on the next push
+        # it's invalidated, otherwise we run at risk that something leaks
+        # memory.  This is usually only a problem in test suite since this
+        # functionality is not active in production environments.
+        top = _request_ctx_stack.top
+        if top is not None and top.preserved:
+            top.pop(top._preserved_exc)
+
+        # Before we push the request context we have to ensure that there
+        # is an application context.
+        app_ctx = _app_ctx_stack.top
+        if app_ctx is None or app_ctx.app != self.app:
+            app_ctx = self.app.app_context()
+            app_ctx.push()
+            self._implicit_app_ctx_stack.append(app_ctx)
+        else:
+            self._implicit_app_ctx_stack.append(None)
+
+        if hasattr(sys, 'exc_clear'):
+            sys.exc_clear()
+
+        _request_ctx_stack.push(self)
+
+        # Open the session at the moment that the request context is available.
+        # This allows a custom open_session method to use the request context.
+        # Only open a new session if this is the first time the request was
+        # pushed, otherwise stream_with_context loses the session.
+        if self.session is None:
+            session_interface = self.app.session_interface
+            self.session = session_interface.open_session(
+                self.app, self.request
+            )
+
+            if self.session is None:
+                self.session = session_interface.make_null_session(self.app)
+
+    def pop(self, exc=_sentinel):
+        """Pops the request context and unbinds it by doing that.  This will
+        also trigger the execution of functions registered by the
+        :meth:`~flask.Flask.teardown_request` decorator.
+
+        .. versionchanged:: 0.9
+           Added the `exc` argument.
+        """
+        app_ctx = self._implicit_app_ctx_stack.pop()
+
+        try:
+            clear_request = False
+            if not self._implicit_app_ctx_stack:
+                self.preserved = False
+                self._preserved_exc = None
+                if exc is _sentinel:
+                    exc = sys.exc_info()[1]
+                self.app.do_teardown_request(exc)
+
+                # If this interpreter supports clearing the exception information
+                # we do that now.  This will only go into effect on Python 2.x,
+                # on 3.x it disappears automatically at the end of the exception
+                # stack.
+                if hasattr(sys, 'exc_clear'):
+                    sys.exc_clear()
+
+                request_close = getattr(self.request, 'close', None)
+                if request_close is not None:
+                    request_close()
+                clear_request = True
+        finally:
+            rv = _request_ctx_stack.pop()
+
+            # get rid of circular dependencies at the end of the request
+            # so that we don't require the GC to be active.
+            if clear_request:
+                rv.request.environ['werkzeug.request'] = None
+
+            # Get rid of the app as well if necessary.
+            if app_ctx is not None:
+                app_ctx.pop(exc)
+
+            assert rv is self, 'Popped wrong request context.  ' \
+                '(%r instead of %r)' % (rv, self)
+
+    def auto_pop(self, exc):
+        if self.request.environ.get('flask._preserve_context') or \
+           (exc is not None and self.app.preserve_context_on_exception):
+            self.preserved = True
+            self._preserved_exc = exc
+        else:
+            self.pop(exc)
+
+    def __enter__(self):
+        self.push()
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        # do not pop the request stack if we are in debug mode and an
+        # exception happened.  This will allow the debugger to still
+        # access the request object in the interactive shell.  Furthermore
+        # the context can be force kept alive for the test client.
+        # See flask.testing for how this works.
+        self.auto_pop(exc_value)
+
+        if BROKEN_PYPY_CTXMGR_EXIT and exc_type is not None:
+            reraise(exc_type, exc_value, tb)
+
+    def __repr__(self):
+        return '<%s \'%s\' [%s] of %s>' % (
+            self.__class__.__name__,
+            self.request.url,
+            self.request.method,
+            self.app.name,
+        )
diff --git a/python/flask/debughelpers.py b/python/flask/debughelpers.py
new file mode 100644
index 0000000..e9765f2
--- /dev/null
+++ b/python/flask/debughelpers.py
@@ -0,0 +1,168 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.debughelpers
+    ~~~~~~~~~~~~~~~~~~
+
+    Various helpers to make the development experience better.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import os
+from warnings import warn
+
+from ._compat import implements_to_string, text_type
+from .app import Flask
+from .blueprints import Blueprint
+from .globals import _request_ctx_stack
+
+
+class UnexpectedUnicodeError(AssertionError, UnicodeError):
+    """Raised in places where we want some better error reporting for
+    unexpected unicode or binary data.
+    """
+
+
+@implements_to_string
+class DebugFilesKeyError(KeyError, AssertionError):
+    """Raised from request.files during debugging.  The idea is that it can
+    provide a better error message than just a generic KeyError/BadRequest.
+    """
+
+    def __init__(self, request, key):
+        form_matches = request.form.getlist(key)
+        buf = ['You tried to access the file "%s" in the request.files '
+               'dictionary but it does not exist.  The mimetype for the request '
+               'is "%s" instead of "multipart/form-data" which means that no '
+               'file contents were transmitted.  To fix this error you should '
+               'provide enctype="multipart/form-data" in your form.' %
+               (key, request.mimetype)]
+        if form_matches:
+            buf.append('\n\nThe browser instead transmitted some file names. '
+                       'This was submitted: %s' % ', '.join('"%s"' % x
+                            for x in form_matches))
+        self.msg = ''.join(buf)
+
+    def __str__(self):
+        return self.msg
+
+
+class FormDataRoutingRedirect(AssertionError):
+    """This exception is raised by Flask in debug mode if it detects a
+    redirect caused by the routing system when the request method is not
+    GET, HEAD or OPTIONS.  Reasoning: form data will be dropped.
+    """
+
+    def __init__(self, request):
+        exc = request.routing_exception
+        buf = ['A request was sent to this URL (%s) but a redirect was '
+               'issued automatically by the routing system to "%s".'
+               % (request.url, exc.new_url)]
+
+        # In case just a slash was appended we can be extra helpful
+        if request.base_url + '/' == exc.new_url.split('?')[0]:
+            buf.append('  The URL was defined with a trailing slash so '
+                       'Flask will automatically redirect to the URL '
+                       'with the trailing slash if it was accessed '
+                       'without one.')
+
+        buf.append('  Make sure to directly send your %s-request to this URL '
+                   'since we can\'t make browsers or HTTP clients redirect '
+                   'with form data reliably or without user interaction.' %
+                   request.method)
+        buf.append('\n\nNote: this exception is only raised in debug mode')
+        AssertionError.__init__(self, ''.join(buf).encode('utf-8'))
+
+
+def attach_enctype_error_multidict(request):
+    """Since Flask 0.8 we're monkeypatching the files object in case a
+    request is detected that does not use multipart form data but the files
+    object is accessed.
+    """
+    oldcls = request.files.__class__
+    class newcls(oldcls):
+        def __getitem__(self, key):
+            try:
+                return oldcls.__getitem__(self, key)
+            except KeyError:
+                if key not in request.form:
+                    raise
+                raise DebugFilesKeyError(request, key)
+    newcls.__name__ = oldcls.__name__
+    newcls.__module__ = oldcls.__module__
+    request.files.__class__ = newcls
+
+
+def _dump_loader_info(loader):
+    yield 'class: %s.%s' % (type(loader).__module__, type(loader).__name__)
+    for key, value in sorted(loader.__dict__.items()):
+        if key.startswith('_'):
+            continue
+        if isinstance(value, (tuple, list)):
+            if not all(isinstance(x, (str, text_type)) for x in value):
+                continue
+            yield '%s:' % key
+            for item in value:
+                yield '  - %s' % item
+            continue
+        elif not isinstance(value, (str, text_type, int, float, bool)):
+            continue
+        yield '%s: %r' % (key, value)
+
+
+def explain_template_loading_attempts(app, template, attempts):
+    """This should help developers understand what failed"""
+    info = ['Locating template "%s":' % template]
+    total_found = 0
+    blueprint = None
+    reqctx = _request_ctx_stack.top
+    if reqctx is not None and reqctx.request.blueprint is not None:
+        blueprint = reqctx.request.blueprint
+
+    for idx, (loader, srcobj, triple) in enumerate(attempts):
+        if isinstance(srcobj, Flask):
+            src_info = 'application "%s"' % srcobj.import_name
+        elif isinstance(srcobj, Blueprint):
+            src_info = 'blueprint "%s" (%s)' % (srcobj.name,
+                                                srcobj.import_name)
+        else:
+            src_info = repr(srcobj)
+
+        info.append('% 5d: trying loader of %s' % (
+            idx + 1, src_info))
+
+        for line in _dump_loader_info(loader):
+            info.append('       %s' % line)
+
+        if triple is None:
+            detail = 'no match'
+        else:
+            detail = 'found (%r)' % (triple[1] or '<string>')
+            total_found += 1
+        info.append('       -> %s' % detail)
+
+    seems_fishy = False
+    if total_found == 0:
+        info.append('Error: the template could not be found.')
+        seems_fishy = True
+    elif total_found > 1:
+        info.append('Warning: multiple loaders returned a match for the template.')
+        seems_fishy = True
+
+    if blueprint is not None and seems_fishy:
+        info.append('  The template was looked up from an endpoint that '
+                    'belongs to the blueprint "%s".' % blueprint)
+        info.append('  Maybe you did not place a template in the right folder?')
+        info.append('  See http://flask.pocoo.org/docs/blueprints/#templates')
+
+    app.logger.info('\n'.join(info))
+
+
+def explain_ignored_app_run():
+    if os.environ.get('WERKZEUG_RUN_MAIN') != 'true':
+        warn(Warning('Silently ignoring app.run() because the '
+                     'application is run from the flask command line '
+                     'executable.  Consider putting app.run() behind an '
+                     'if __name__ == "__main__" guard to silence this '
+                     'warning.'), stacklevel=3)
diff --git a/python/flask/globals.py b/python/flask/globals.py
new file mode 100644
index 0000000..7d50a6f
--- /dev/null
+++ b/python/flask/globals.py
@@ -0,0 +1,61 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.globals
+    ~~~~~~~~~~~~~
+
+    Defines all the global objects that are proxies to the current
+    active context.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from functools import partial
+from werkzeug.local import LocalStack, LocalProxy
+
+
+_request_ctx_err_msg = '''\
+Working outside of request context.
+
+This typically means that you attempted to use functionality that needed
+an active HTTP request.  Consult the documentation on testing for
+information about how to avoid this problem.\
+'''
+_app_ctx_err_msg = '''\
+Working outside of application context.
+
+This typically means that you attempted to use functionality that needed
+to interface with the current application object in some way. To solve
+this, set up an application context with app.app_context().  See the
+documentation for more information.\
+'''
+
+
+def _lookup_req_object(name):
+    top = _request_ctx_stack.top
+    if top is None:
+        raise RuntimeError(_request_ctx_err_msg)
+    return getattr(top, name)
+
+
+def _lookup_app_object(name):
+    top = _app_ctx_stack.top
+    if top is None:
+        raise RuntimeError(_app_ctx_err_msg)
+    return getattr(top, name)
+
+
+def _find_app():
+    top = _app_ctx_stack.top
+    if top is None:
+        raise RuntimeError(_app_ctx_err_msg)
+    return top.app
+
+
+# context locals
+_request_ctx_stack = LocalStack()
+_app_ctx_stack = LocalStack()
+current_app = LocalProxy(_find_app)
+request = LocalProxy(partial(_lookup_req_object, 'request'))
+session = LocalProxy(partial(_lookup_req_object, 'session'))
+g = LocalProxy(partial(_lookup_app_object, 'g'))
diff --git a/python/flask/helpers.py b/python/flask/helpers.py
new file mode 100644
index 0000000..158edc5
--- /dev/null
+++ b/python/flask/helpers.py
@@ -0,0 +1,1051 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.helpers
+    ~~~~~~~~~~~~~
+
+    Implements various helpers.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import os
+import socket
+import sys
+import pkgutil
+import posixpath
+import mimetypes
+from time import time
+from zlib import adler32
+from threading import RLock
+import unicodedata
+from werkzeug.routing import BuildError
+from functools import update_wrapper
+
+from werkzeug.urls import url_quote
+from werkzeug.datastructures import Headers, Range
+from werkzeug.exceptions import BadRequest, NotFound, \
+    RequestedRangeNotSatisfiable
+
+from werkzeug.wsgi import wrap_file
+from jinja2 import FileSystemLoader
+
+from .signals import message_flashed
+from .globals import session, _request_ctx_stack, _app_ctx_stack, \
+     current_app, request
+from ._compat import string_types, text_type, PY2
+
+# sentinel
+_missing = object()
+
+
+# what separators does this operating system provide that are not a slash?
+# this is used by the send_from_directory function to ensure that nobody is
+# able to access files from outside the filesystem.
+_os_alt_seps = list(sep for sep in [os.path.sep, os.path.altsep]
+                    if sep not in (None, '/'))
+
+
+def get_env():
+    """Get the environment the app is running in, indicated by the
+    :envvar:`FLASK_ENV` environment variable. The default is
+    ``'production'``.
+    """
+    return os.environ.get('FLASK_ENV') or 'production'
+
+
+def get_debug_flag():
+    """Get whether debug mode should be enabled for the app, indicated
+    by the :envvar:`FLASK_DEBUG` environment variable. The default is
+    ``True`` if :func:`.get_env` returns ``'development'``, or ``False``
+    otherwise.
+    """
+    val = os.environ.get('FLASK_DEBUG')
+
+    if not val:
+        return get_env() == 'development'
+
+    return val.lower() not in ('0', 'false', 'no')
+
+
+def get_load_dotenv(default=True):
+    """Get whether the user has disabled loading dotenv files by setting
+    :envvar:`FLASK_SKIP_DOTENV`. The default is ``True``, load the
+    files.
+
+    :param default: What to return if the env var isn't set.
+    """
+    val = os.environ.get('FLASK_SKIP_DOTENV')
+
+    if not val:
+        return default
+
+    return val.lower() in ('0', 'false', 'no')
+
+
+def _endpoint_from_view_func(view_func):
+    """Internal helper that returns the default endpoint for a given
+    function.  This always is the function name.
+    """
+    assert view_func is not None, 'expected view func if endpoint ' \
+                                  'is not provided.'
+    return view_func.__name__
+
+
+def stream_with_context(generator_or_function):
+    """Request contexts disappear when the response is started on the server.
+    This is done for efficiency reasons and to make it less likely to encounter
+    memory leaks with badly written WSGI middlewares.  The downside is that if
+    you are using streamed responses, the generator cannot access request bound
+    information any more.
+
+    This function however can help you keep the context around for longer::
+
+        from flask import stream_with_context, request, Response
+
+        @app.route('/stream')
+        def streamed_response():
+            @stream_with_context
+            def generate():
+                yield 'Hello '
+                yield request.args['name']
+                yield '!'
+            return Response(generate())
+
+    Alternatively it can also be used around a specific generator::
+
+        from flask import stream_with_context, request, Response
+
+        @app.route('/stream')
+        def streamed_response():
+            def generate():
+                yield 'Hello '
+                yield request.args['name']
+                yield '!'
+            return Response(stream_with_context(generate()))
+
+    .. versionadded:: 0.9
+    """
+    try:
+        gen = iter(generator_or_function)
+    except TypeError:
+        def decorator(*args, **kwargs):
+            gen = generator_or_function(*args, **kwargs)
+            return stream_with_context(gen)
+        return update_wrapper(decorator, generator_or_function)
+
+    def generator():
+        ctx = _request_ctx_stack.top
+        if ctx is None:
+            raise RuntimeError('Attempted to stream with context but '
+                'there was no context in the first place to keep around.')
+        with ctx:
+            # Dummy sentinel.  Has to be inside the context block or we're
+            # not actually keeping the context around.
+            yield None
+
+            # The try/finally is here so that if someone passes a WSGI level
+            # iterator in we're still running the cleanup logic.  Generators
+            # don't need that because they are closed on their destruction
+            # automatically.
+            try:
+                for item in gen:
+                    yield item
+            finally:
+                if hasattr(gen, 'close'):
+                    gen.close()
+
+    # The trick is to start the generator.  Then the code execution runs until
+    # the first dummy None is yielded at which point the context was already
+    # pushed.  This item is discarded.  Then when the iteration continues the
+    # real generator is executed.
+    wrapped_g = generator()
+    next(wrapped_g)
+    return wrapped_g
+
+
+def make_response(*args):
+    """Sometimes it is necessary to set additional headers in a view.  Because
+    views do not have to return response objects but can return a value that
+    is converted into a response object by Flask itself, it becomes tricky to
+    add headers to it.  This function can be called instead of using a return
+    and you will get a response object which you can use to attach headers.
+
+    If view looked like this and you want to add a new header::
+
+        def index():
+            return render_template('index.html', foo=42)
+
+    You can now do something like this::
+
+        def index():
+            response = make_response(render_template('index.html', foo=42))
+            response.headers['X-Parachutes'] = 'parachutes are cool'
+            return response
+
+    This function accepts the very same arguments you can return from a
+    view function.  This for example creates a response with a 404 error
+    code::
+
+        response = make_response(render_template('not_found.html'), 404)
+
+    The other use case of this function is to force the return value of a
+    view function into a response which is helpful with view
+    decorators::
+
+        response = make_response(view_function())
+        response.headers['X-Parachutes'] = 'parachutes are cool'
+
+    Internally this function does the following things:
+
+    -   if no arguments are passed, it creates a new response argument
+    -   if one argument is passed, :meth:`flask.Flask.make_response`
+        is invoked with it.
+    -   if more than one argument is passed, the arguments are passed
+        to the :meth:`flask.Flask.make_response` function as tuple.
+
+    .. versionadded:: 0.6
+    """
+    if not args:
+        return current_app.response_class()
+    if len(args) == 1:
+        args = args[0]
+    return current_app.make_response(args)
+
+
+def url_for(endpoint, **values):
+    """Generates a URL to the given endpoint with the method provided.
+
+    Variable arguments that are unknown to the target endpoint are appended
+    to the generated URL as query arguments.  If the value of a query argument
+    is ``None``, the whole pair is skipped.  In case blueprints are active
+    you can shortcut references to the same blueprint by prefixing the
+    local endpoint with a dot (``.``).
+
+    This will reference the index function local to the current blueprint::
+
+        url_for('.index')
+
+    For more information, head over to the :ref:`Quickstart <url-building>`.
+
+    To integrate applications, :class:`Flask` has a hook to intercept URL build
+    errors through :attr:`Flask.url_build_error_handlers`.  The `url_for`
+    function results in a :exc:`~werkzeug.routing.BuildError` when the current
+    app does not have a URL for the given endpoint and values.  When it does, the
+    :data:`~flask.current_app` calls its :attr:`~Flask.url_build_error_handlers` if
+    it is not ``None``, which can return a string to use as the result of
+    `url_for` (instead of `url_for`'s default to raise the
+    :exc:`~werkzeug.routing.BuildError` exception) or re-raise the exception.
+    An example::
+
+        def external_url_handler(error, endpoint, values):
+            "Looks up an external URL when `url_for` cannot build a URL."
+            # This is an example of hooking the build_error_handler.
+            # Here, lookup_url is some utility function you've built
+            # which looks up the endpoint in some external URL registry.
+            url = lookup_url(endpoint, **values)
+            if url is None:
+                # External lookup did not have a URL.
+                # Re-raise the BuildError, in context of original traceback.
+                exc_type, exc_value, tb = sys.exc_info()
+                if exc_value is error:
+                    raise exc_type, exc_value, tb
+                else:
+                    raise error
+            # url_for will use this result, instead of raising BuildError.
+            return url
+
+        app.url_build_error_handlers.append(external_url_handler)
+
+    Here, `error` is the instance of :exc:`~werkzeug.routing.BuildError`, and
+    `endpoint` and `values` are the arguments passed into `url_for`.  Note
+    that this is for building URLs outside the current application, and not for
+    handling 404 NotFound errors.
+
+    .. versionadded:: 0.10
+       The `_scheme` parameter was added.
+
+    .. versionadded:: 0.9
+       The `_anchor` and `_method` parameters were added.
+
+    .. versionadded:: 0.9
+       Calls :meth:`Flask.handle_build_error` on
+       :exc:`~werkzeug.routing.BuildError`.
+
+    :param endpoint: the endpoint of the URL (name of the function)
+    :param values: the variable arguments of the URL rule
+    :param _external: if set to ``True``, an absolute URL is generated. Server
+      address can be changed via ``SERVER_NAME`` configuration variable which
+      falls back to the `Host` header, then to the IP and port of the request.
+    :param _scheme: a string specifying the desired URL scheme. The `_external`
+      parameter must be set to ``True`` or a :exc:`ValueError` is raised. The default
+      behavior uses the same scheme as the current request, or
+      ``PREFERRED_URL_SCHEME`` from the :ref:`app configuration <config>` if no
+      request context is available. As of Werkzeug 0.10, this also can be set
+      to an empty string to build protocol-relative URLs.
+    :param _anchor: if provided this is added as anchor to the URL.
+    :param _method: if provided this explicitly specifies an HTTP method.
+    """
+    appctx = _app_ctx_stack.top
+    reqctx = _request_ctx_stack.top
+
+    if appctx is None:
+        raise RuntimeError(
+            'Attempted to generate a URL without the application context being'
+            ' pushed. This has to be executed when application context is'
+            ' available.'
+        )
+
+    # If request specific information is available we have some extra
+    # features that support "relative" URLs.
+    if reqctx is not None:
+        url_adapter = reqctx.url_adapter
+        blueprint_name = request.blueprint
+
+        if endpoint[:1] == '.':
+            if blueprint_name is not None:
+                endpoint = blueprint_name + endpoint
+            else:
+                endpoint = endpoint[1:]
+
+        external = values.pop('_external', False)
+
+    # Otherwise go with the url adapter from the appctx and make
+    # the URLs external by default.
+    else:
+        url_adapter = appctx.url_adapter
+
+        if url_adapter is None:
+            raise RuntimeError(
+                'Application was not able to create a URL adapter for request'
+                ' independent URL generation. You might be able to fix this by'
+                ' setting the SERVER_NAME config variable.'
+            )
+
+        external = values.pop('_external', True)
+
+    anchor = values.pop('_anchor', None)
+    method = values.pop('_method', None)
+    scheme = values.pop('_scheme', None)
+    appctx.app.inject_url_defaults(endpoint, values)
+
+    # This is not the best way to deal with this but currently the
+    # underlying Werkzeug router does not support overriding the scheme on
+    # a per build call basis.
+    old_scheme = None
+    if scheme is not None:
+        if not external:
+            raise ValueError('When specifying _scheme, _external must be True')
+        old_scheme = url_adapter.url_scheme
+        url_adapter.url_scheme = scheme
+
+    try:
+        try:
+            rv = url_adapter.build(endpoint, values, method=method,
+                                   force_external=external)
+        finally:
+            if old_scheme is not None:
+                url_adapter.url_scheme = old_scheme
+    except BuildError as error:
+        # We need to inject the values again so that the app callback can
+        # deal with that sort of stuff.
+        values['_external'] = external
+        values['_anchor'] = anchor
+        values['_method'] = method
+        values['_scheme'] = scheme
+        return appctx.app.handle_url_build_error(error, endpoint, values)
+
+    if anchor is not None:
+        rv += '#' + url_quote(anchor)
+    return rv
+
+
+def get_template_attribute(template_name, attribute):
+    """Loads a macro (or variable) a template exports.  This can be used to
+    invoke a macro from within Python code.  If you for example have a
+    template named :file:`_cider.html` with the following contents:
+
+    .. sourcecode:: html+jinja
+
+       {% macro hello(name) %}Hello {{ name }}!{% endmacro %}
+
+    You can access this from Python code like this::
+
+        hello = get_template_attribute('_cider.html', 'hello')
+        return hello('World')
+
+    .. versionadded:: 0.2
+
+    :param template_name: the name of the template
+    :param attribute: the name of the variable of macro to access
+    """
+    return getattr(current_app.jinja_env.get_template(template_name).module,
+                   attribute)
+
+
+def flash(message, category='message'):
+    """Flashes a message to the next request.  In order to remove the
+    flashed message from the session and to display it to the user,
+    the template has to call :func:`get_flashed_messages`.
+
+    .. versionchanged:: 0.3
+       `category` parameter added.
+
+    :param message: the message to be flashed.
+    :param category: the category for the message.  The following values
+                     are recommended: ``'message'`` for any kind of message,
+                     ``'error'`` for errors, ``'info'`` for information
+                     messages and ``'warning'`` for warnings.  However any
+                     kind of string can be used as category.
+    """
+    # Original implementation:
+    #
+    #     session.setdefault('_flashes', []).append((category, message))
+    #
+    # This assumed that changes made to mutable structures in the session are
+    # always in sync with the session object, which is not true for session
+    # implementations that use external storage for keeping their keys/values.
+    flashes = session.get('_flashes', [])
+    flashes.append((category, message))
+    session['_flashes'] = flashes
+    message_flashed.send(current_app._get_current_object(),
+                         message=message, category=category)
+
+
+def get_flashed_messages(with_categories=False, category_filter=[]):
+    """Pulls all flashed messages from the session and returns them.
+    Further calls in the same request to the function will return
+    the same messages.  By default just the messages are returned,
+    but when `with_categories` is set to ``True``, the return value will
+    be a list of tuples in the form ``(category, message)`` instead.
+
+    Filter the flashed messages to one or more categories by providing those
+    categories in `category_filter`.  This allows rendering categories in
+    separate html blocks.  The `with_categories` and `category_filter`
+    arguments are distinct:
+
+    * `with_categories` controls whether categories are returned with message
+      text (``True`` gives a tuple, where ``False`` gives just the message text).
+    * `category_filter` filters the messages down to only those matching the
+      provided categories.
+
+    See :ref:`message-flashing-pattern` for examples.
+
+    .. versionchanged:: 0.3
+       `with_categories` parameter added.
+
+    .. versionchanged:: 0.9
+        `category_filter` parameter added.
+
+    :param with_categories: set to ``True`` to also receive categories.
+    :param category_filter: whitelist of categories to limit return values
+    """
+    flashes = _request_ctx_stack.top.flashes
+    if flashes is None:
+        _request_ctx_stack.top.flashes = flashes = session.pop('_flashes') \
+            if '_flashes' in session else []
+    if category_filter:
+        flashes = list(filter(lambda f: f[0] in category_filter, flashes))
+    if not with_categories:
+        return [x[1] for x in flashes]
+    return flashes
+
+
+def send_file(filename_or_fp, mimetype=None, as_attachment=False,
+              attachment_filename=None, add_etags=True,
+              cache_timeout=None, conditional=False, last_modified=None):
+    """Sends the contents of a file to the client.  This will use the
+    most efficient method available and configured.  By default it will
+    try to use the WSGI server's file_wrapper support.  Alternatively
+    you can set the application's :attr:`~Flask.use_x_sendfile` attribute
+    to ``True`` to directly emit an ``X-Sendfile`` header.  This however
+    requires support of the underlying webserver for ``X-Sendfile``.
+
+    By default it will try to guess the mimetype for you, but you can
+    also explicitly provide one.  For extra security you probably want
+    to send certain files as attachment (HTML for instance).  The mimetype
+    guessing requires a `filename` or an `attachment_filename` to be
+    provided.
+
+    ETags will also be attached automatically if a `filename` is provided. You
+    can turn this off by setting `add_etags=False`.
+
+    If `conditional=True` and `filename` is provided, this method will try to
+    upgrade the response stream to support range requests.  This will allow
+    the request to be answered with partial content response.
+
+    Please never pass filenames to this function from user sources;
+    you should use :func:`send_from_directory` instead.
+
+    .. versionadded:: 0.2
+
+    .. versionadded:: 0.5
+       The `add_etags`, `cache_timeout` and `conditional` parameters were
+       added.  The default behavior is now to attach etags.
+
+    .. versionchanged:: 0.7
+       mimetype guessing and etag support for file objects was
+       deprecated because it was unreliable.  Pass a filename if you are
+       able to, otherwise attach an etag yourself.  This functionality
+       will be removed in Flask 1.0
+
+    .. versionchanged:: 0.9
+       cache_timeout pulls its default from application config, when None.
+
+    .. versionchanged:: 0.12
+       The filename is no longer automatically inferred from file objects. If
+       you want to use automatic mimetype and etag support, pass a filepath via
+       `filename_or_fp` or `attachment_filename`.
+
+    .. versionchanged:: 0.12
+       The `attachment_filename` is preferred over `filename` for MIME-type
+       detection.
+
+    .. versionchanged:: 1.0
+        UTF-8 filenames, as specified in `RFC 2231`_, are supported.
+
+    .. _RFC 2231: https://tools.ietf.org/html/rfc2231#section-4
+
+    .. versionchanged:: 1.0.3
+        Filenames are encoded with ASCII instead of Latin-1 for broader
+        compatibility with WSGI servers.
+
+    :param filename_or_fp: the filename of the file to send.
+                           This is relative to the :attr:`~Flask.root_path`
+                           if a relative path is specified.
+                           Alternatively a file object might be provided in
+                           which case ``X-Sendfile`` might not work and fall
+                           back to the traditional method.  Make sure that the
+                           file pointer is positioned at the start of data to
+                           send before calling :func:`send_file`.
+    :param mimetype: the mimetype of the file if provided. If a file path is
+                     given, auto detection happens as fallback, otherwise an
+                     error will be raised.
+    :param as_attachment: set to ``True`` if you want to send this file with
+                          a ``Content-Disposition: attachment`` header.
+    :param attachment_filename: the filename for the attachment if it
+                                differs from the file's filename.
+    :param add_etags: set to ``False`` to disable attaching of etags.
+    :param conditional: set to ``True`` to enable conditional responses.
+
+    :param cache_timeout: the timeout in seconds for the headers. When ``None``
+                          (default), this value is set by
+                          :meth:`~Flask.get_send_file_max_age` of
+                          :data:`~flask.current_app`.
+    :param last_modified: set the ``Last-Modified`` header to this value,
+        a :class:`~datetime.datetime` or timestamp.
+        If a file was passed, this overrides its mtime.
+    """
+    mtime = None
+    fsize = None
+    if isinstance(filename_or_fp, string_types):
+        filename = filename_or_fp
+        if not os.path.isabs(filename):
+            filename = os.path.join(current_app.root_path, filename)
+        file = None
+        if attachment_filename is None:
+            attachment_filename = os.path.basename(filename)
+    else:
+        file = filename_or_fp
+        filename = None
+
+    if mimetype is None:
+        if attachment_filename is not None:
+            mimetype = mimetypes.guess_type(attachment_filename)[0] \
+                or 'application/octet-stream'
+
+        if mimetype is None:
+            raise ValueError(
+                'Unable to infer MIME-type because no filename is available. '
+                'Please set either `attachment_filename`, pass a filepath to '
+                '`filename_or_fp` or set your own MIME-type via `mimetype`.'
+            )
+
+    headers = Headers()
+    if as_attachment:
+        if attachment_filename is None:
+            raise TypeError('filename unavailable, required for '
+                            'sending as attachment')
+
+        if not isinstance(attachment_filename, text_type):
+            attachment_filename = attachment_filename.decode('utf-8')
+
+        try:
+            attachment_filename = attachment_filename.encode('ascii')
+        except UnicodeEncodeError:
+            filenames = {
+                'filename': unicodedata.normalize(
+                    'NFKD', attachment_filename).encode('ascii', 'ignore'),
+                'filename*': "UTF-8''%s" % url_quote(attachment_filename),
+            }
+        else:
+            filenames = {'filename': attachment_filename}
+
+        headers.add('Content-Disposition', 'attachment', **filenames)
+
+    if current_app.use_x_sendfile and filename:
+        if file is not None:
+            file.close()
+        headers['X-Sendfile'] = filename
+        fsize = os.path.getsize(filename)
+        headers['Content-Length'] = fsize
+        data = None
+    else:
+        if file is None:
+            file = open(filename, 'rb')
+            mtime = os.path.getmtime(filename)
+            fsize = os.path.getsize(filename)
+            headers['Content-Length'] = fsize
+        data = wrap_file(request.environ, file)
+
+    rv = current_app.response_class(data, mimetype=mimetype, headers=headers,
+                                    direct_passthrough=True)
+
+    if last_modified is not None:
+        rv.last_modified = last_modified
+    elif mtime is not None:
+        rv.last_modified = mtime
+
+    rv.cache_control.public = True
+    if cache_timeout is None:
+        cache_timeout = current_app.get_send_file_max_age(filename)
+    if cache_timeout is not None:
+        rv.cache_control.max_age = cache_timeout
+        rv.expires = int(time() + cache_timeout)
+
+    if add_etags and filename is not None:
+        from warnings import warn
+
+        try:
+            rv.set_etag('%s-%s-%s' % (
+                os.path.getmtime(filename),
+                os.path.getsize(filename),
+                adler32(
+                    filename.encode('utf-8') if isinstance(filename, text_type)
+                    else filename
+                ) & 0xffffffff
+            ))
+        except OSError:
+            warn('Access %s failed, maybe it does not exist, so ignore etags in '
+                 'headers' % filename, stacklevel=2)
+
+    if conditional:
+        try:
+            rv = rv.make_conditional(request, accept_ranges=True,
+                                     complete_length=fsize)
+        except RequestedRangeNotSatisfiable:
+            if file is not None:
+                file.close()
+            raise
+        # make sure we don't send x-sendfile for servers that
+        # ignore the 304 status code for x-sendfile.
+        if rv.status_code == 304:
+            rv.headers.pop('x-sendfile', None)
+    return rv
+
+
+def safe_join(directory, *pathnames):
+    """Safely join `directory` and zero or more untrusted `pathnames`
+    components.
+
+    Example usage::
+
+        @app.route('/wiki/<path:filename>')
+        def wiki_page(filename):
+            filename = safe_join(app.config['WIKI_FOLDER'], filename)
+            with open(filename, 'rb') as fd:
+                content = fd.read()  # Read and process the file content...
+
+    :param directory: the trusted base directory.
+    :param pathnames: the untrusted pathnames relative to that directory.
+    :raises: :class:`~werkzeug.exceptions.NotFound` if one or more passed
+            paths fall out of its boundaries.
+    """
+
+    parts = [directory]
+
+    for filename in pathnames:
+        if filename != '':
+            filename = posixpath.normpath(filename)
+
+        if (
+            any(sep in filename for sep in _os_alt_seps)
+            or os.path.isabs(filename)
+            or filename == '..'
+            or filename.startswith('../')
+        ):
+            raise NotFound()
+
+        parts.append(filename)
+
+    return posixpath.join(*parts)
+
+
+def send_from_directory(directory, filename, **options):
+    """Send a file from a given directory with :func:`send_file`.  This
+    is a secure way to quickly expose static files from an upload folder
+    or something similar.
+
+    Example usage::
+
+        @app.route('/uploads/<path:filename>')
+        def download_file(filename):
+            return send_from_directory(app.config['UPLOAD_FOLDER'],
+                                       filename, as_attachment=True)
+
+    .. admonition:: Sending files and Performance
+
+       It is strongly recommended to activate either ``X-Sendfile`` support in
+       your webserver or (if no authentication happens) to tell the webserver
+       to serve files for the given path on its own without calling into the
+       web application for improved performance.
+
+    .. versionadded:: 0.5
+
+    :param directory: the directory where all the files are stored.
+    :param filename: the filename relative to that directory to
+                     download.
+    :param options: optional keyword arguments that are directly
+                    forwarded to :func:`send_file`.
+    """
+    filename = safe_join(directory, filename)
+    if not os.path.isabs(filename):
+        filename = os.path.join(current_app.root_path, filename)
+    try:
+        if not os.path.isfile(filename):
+            raise NotFound()
+    except (TypeError, ValueError):
+        raise BadRequest()
+    options.setdefault('conditional', True)
+    return send_file(filename, **options)
+
+
+def get_root_path(import_name):
+    """Returns the path to a package or cwd if that cannot be found.  This
+    returns the path of a package or the folder that contains a module.
+
+    Not to be confused with the package path returned by :func:`find_package`.
+    """
+    # Module already imported and has a file attribute.  Use that first.
+    mod = sys.modules.get(import_name)
+    if mod is not None and hasattr(mod, '__file__'):
+        return os.path.dirname(os.path.abspath(mod.__file__))
+
+    # Next attempt: check the loader.
+    loader = pkgutil.get_loader(import_name)
+
+    # Loader does not exist or we're referring to an unloaded main module
+    # or a main module without path (interactive sessions), go with the
+    # current working directory.
+    if loader is None or import_name == '__main__':
+        return os.getcwd()
+
+    # For .egg, zipimporter does not have get_filename until Python 2.7.
+    # Some other loaders might exhibit the same behavior.
+    if hasattr(loader, 'get_filename'):
+        filepath = loader.get_filename(import_name)
+    else:
+        # Fall back to imports.
+        __import__(import_name)
+        mod = sys.modules[import_name]
+        filepath = getattr(mod, '__file__', None)
+
+        # If we don't have a filepath it might be because we are a
+        # namespace package.  In this case we pick the root path from the
+        # first module that is contained in our package.
+        if filepath is None:
+            raise RuntimeError('No root path can be found for the provided '
+                               'module "%s".  This can happen because the '
+                               'module came from an import hook that does '
+                               'not provide file name information or because '
+                               'it\'s a namespace package.  In this case '
+                               'the root path needs to be explicitly '
+                               'provided.' % import_name)
+
+    # filepath is import_name.py for a module, or __init__.py for a package.
+    return os.path.dirname(os.path.abspath(filepath))
+
+
+def _matching_loader_thinks_module_is_package(loader, mod_name):
+    """Given the loader that loaded a module and the module this function
+    attempts to figure out if the given module is actually a package.
+    """
+    # If the loader can tell us if something is a package, we can
+    # directly ask the loader.
+    if hasattr(loader, 'is_package'):
+        return loader.is_package(mod_name)
+    # importlib's namespace loaders do not have this functionality but
+    # all the modules it loads are packages, so we can take advantage of
+    # this information.
+    elif (loader.__class__.__module__ == '_frozen_importlib' and
+          loader.__class__.__name__ == 'NamespaceLoader'):
+        return True
+    # Otherwise we need to fail with an error that explains what went
+    # wrong.
+    raise AttributeError(
+        ('%s.is_package() method is missing but is required by Flask of '
+         'PEP 302 import hooks.  If you do not use import hooks and '
+         'you encounter this error please file a bug against Flask.') %
+        loader.__class__.__name__)
+
+
+def find_package(import_name):
+    """Finds a package and returns the prefix (or None if the package is
+    not installed) as well as the folder that contains the package or
+    module as a tuple.  The package path returned is the module that would
+    have to be added to the pythonpath in order to make it possible to
+    import the module.  The prefix is the path below which a UNIX like
+    folder structure exists (lib, share etc.).
+    """
+    root_mod_name = import_name.split('.')[0]
+    loader = pkgutil.get_loader(root_mod_name)
+    if loader is None or import_name == '__main__':
+        # import name is not found, or interactive/main module
+        package_path = os.getcwd()
+    else:
+        # For .egg, zipimporter does not have get_filename until Python 2.7.
+        if hasattr(loader, 'get_filename'):
+            filename = loader.get_filename(root_mod_name)
+        elif hasattr(loader, 'archive'):
+            # zipimporter's loader.archive points to the .egg or .zip
+            # archive filename is dropped in call to dirname below.
+            filename = loader.archive
+        else:
+            # At least one loader is missing both get_filename and archive:
+            # Google App Engine's HardenedModulesHook
+            #
+            # Fall back to imports.
+            __import__(import_name)
+            filename = sys.modules[import_name].__file__
+        package_path = os.path.abspath(os.path.dirname(filename))
+
+        # In case the root module is a package we need to chop of the
+        # rightmost part.  This needs to go through a helper function
+        # because of python 3.3 namespace packages.
+        if _matching_loader_thinks_module_is_package(
+                loader, root_mod_name):
+            package_path = os.path.dirname(package_path)
+
+    site_parent, site_folder = os.path.split(package_path)
+    py_prefix = os.path.abspath(sys.prefix)
+    if package_path.startswith(py_prefix):
+        return py_prefix, package_path
+    elif site_folder.lower() == 'site-packages':
+        parent, folder = os.path.split(site_parent)
+        # Windows like installations
+        if folder.lower() == 'lib':
+            base_dir = parent
+        # UNIX like installations
+        elif os.path.basename(parent).lower() == 'lib':
+            base_dir = os.path.dirname(parent)
+        else:
+            base_dir = site_parent
+        return base_dir, package_path
+    return None, package_path
+
+
+class locked_cached_property(object):
+    """A decorator that converts a function into a lazy property.  The
+    function wrapped is called the first time to retrieve the result
+    and then that calculated result is used the next time you access
+    the value.  Works like the one in Werkzeug but has a lock for
+    thread safety.
+    """
+
+    def __init__(self, func, name=None, doc=None):
+        self.__name__ = name or func.__name__
+        self.__module__ = func.__module__
+        self.__doc__ = doc or func.__doc__
+        self.func = func
+        self.lock = RLock()
+
+    def __get__(self, obj, type=None):
+        if obj is None:
+            return self
+        with self.lock:
+            value = obj.__dict__.get(self.__name__, _missing)
+            if value is _missing:
+                value = self.func(obj)
+                obj.__dict__[self.__name__] = value
+            return value
+
+
+class _PackageBoundObject(object):
+    #: The name of the package or module that this app belongs to. Do not
+    #: change this once it is set by the constructor.
+    import_name = None
+
+    #: Location of the template files to be added to the template lookup.
+    #: ``None`` if templates should not be added.
+    template_folder = None
+
+    #: Absolute path to the package on the filesystem. Used to look up
+    #: resources contained in the package.
+    root_path = None
+
+    def __init__(self, import_name, template_folder=None, root_path=None):
+        self.import_name = import_name
+        self.template_folder = template_folder
+
+        if root_path is None:
+            root_path = get_root_path(self.import_name)
+
+        self.root_path = root_path
+        self._static_folder = None
+        self._static_url_path = None
+
+    def _get_static_folder(self):
+        if self._static_folder is not None:
+            return os.path.join(self.root_path, self._static_folder)
+
+    def _set_static_folder(self, value):
+        self._static_folder = value
+
+    static_folder = property(
+        _get_static_folder, _set_static_folder,
+        doc='The absolute path to the configured static folder.'
+    )
+    del _get_static_folder, _set_static_folder
+
+    def _get_static_url_path(self):
+        if self._static_url_path is not None:
+            return self._static_url_path
+
+        if self.static_folder is not None:
+            return '/' + os.path.basename(self.static_folder)
+
+    def _set_static_url_path(self, value):
+        self._static_url_path = value
+
+    static_url_path = property(
+        _get_static_url_path, _set_static_url_path,
+        doc='The URL prefix that the static route will be registered for.'
+    )
+    del _get_static_url_path, _set_static_url_path
+
+    @property
+    def has_static_folder(self):
+        """This is ``True`` if the package bound object's container has a
+        folder for static files.
+
+        .. versionadded:: 0.5
+        """
+        return self.static_folder is not None
+
+    @locked_cached_property
+    def jinja_loader(self):
+        """The Jinja loader for this package bound object.
+
+        .. versionadded:: 0.5
+        """
+        if self.template_folder is not None:
+            return FileSystemLoader(os.path.join(self.root_path,
+                                                 self.template_folder))
+
+    def get_send_file_max_age(self, filename):
+        """Provides default cache_timeout for the :func:`send_file` functions.
+
+        By default, this function returns ``SEND_FILE_MAX_AGE_DEFAULT`` from
+        the configuration of :data:`~flask.current_app`.
+
+        Static file functions such as :func:`send_from_directory` use this
+        function, and :func:`send_file` calls this function on
+        :data:`~flask.current_app` when the given cache_timeout is ``None``. If a
+        cache_timeout is given in :func:`send_file`, that timeout is used;
+        otherwise, this method is called.
+
+        This allows subclasses to change the behavior when sending files based
+        on the filename.  For example, to set the cache timeout for .js files
+        to 60 seconds::
+
+            class MyFlask(flask.Flask):
+                def get_send_file_max_age(self, name):
+                    if name.lower().endswith('.js'):
+                        return 60
+                    return flask.Flask.get_send_file_max_age(self, name)
+
+        .. versionadded:: 0.9
+        """
+        return total_seconds(current_app.send_file_max_age_default)
+
+    def send_static_file(self, filename):
+        """Function used internally to send static files from the static
+        folder to the browser.
+
+        .. versionadded:: 0.5
+        """
+        if not self.has_static_folder:
+            raise RuntimeError('No static folder for this object')
+        # Ensure get_send_file_max_age is called in all cases.
+        # Here, we ensure get_send_file_max_age is called for Blueprints.
+        cache_timeout = self.get_send_file_max_age(filename)
+        return send_from_directory(self.static_folder, filename,
+                                   cache_timeout=cache_timeout)
+
+    def open_resource(self, resource, mode='rb'):
+        """Opens a resource from the application's resource folder.  To see
+        how this works, consider the following folder structure::
+
+            /myapplication.py
+            /schema.sql
+            /static
+                /style.css
+            /templates
+                /layout.html
+                /index.html
+
+        If you want to open the :file:`schema.sql` file you would do the
+        following::
+
+            with app.open_resource('schema.sql') as f:
+                contents = f.read()
+                do_something_with(contents)
+
+        :param resource: the name of the resource.  To access resources within
+                         subfolders use forward slashes as separator.
+        :param mode: resource file opening mode, default is 'rb'.
+        """
+        if mode not in ('r', 'rb'):
+            raise ValueError('Resources can only be opened for reading')
+        return open(os.path.join(self.root_path, resource), mode)
+
+
+def total_seconds(td):
+    """Returns the total seconds from a timedelta object.
+
+    :param timedelta td: the timedelta to be converted in seconds
+
+    :returns: number of seconds
+    :rtype: int
+    """
+    return td.days * 60 * 60 * 24 + td.seconds
+
+
+def is_ip(value):
+    """Determine if the given string is an IP address.
+
+    Python 2 on Windows doesn't provide ``inet_pton``, so this only
+    checks IPv4 addresses in that environment.
+
+    :param value: value to check
+    :type value: str
+
+    :return: True if string is an IP address
+    :rtype: bool
+    """
+    if PY2 and os.name == 'nt':
+        try:
+            socket.inet_aton(value)
+            return True
+        except socket.error:
+            return False
+
+    for family in (socket.AF_INET, socket.AF_INET6):
+        try:
+            socket.inet_pton(family, value)
+        except socket.error:
+            pass
+        else:
+            return True
+
+    return False
diff --git a/python/flask/json/__init__.py b/python/flask/json/__init__.py
new file mode 100644
index 0000000..c24286c
--- /dev/null
+++ b/python/flask/json/__init__.py
@@ -0,0 +1,357 @@
+# -*- coding: utf-8 -*-
+"""
+flask.json
+~~~~~~~~~~
+
+:copyright: © 2010 by the Pallets team.
+:license: BSD, see LICENSE for more details.
+"""
+import codecs
+import io
+import uuid
+from datetime import date, datetime
+from flask.globals import current_app, request
+from flask._compat import text_type, PY2
+
+from werkzeug.http import http_date
+from jinja2 import Markup
+
+# Use the same json implementation as itsdangerous on which we
+# depend anyways.
+from itsdangerous import json as _json
+
+
+# Figure out if simplejson escapes slashes.  This behavior was changed
+# from one version to another without reason.
+_slash_escape = '\\/' not in _json.dumps('/')
+
+
+__all__ = ['dump', 'dumps', 'load', 'loads', 'htmlsafe_dump',
+           'htmlsafe_dumps', 'JSONDecoder', 'JSONEncoder',
+           'jsonify']
+
+
+def _wrap_reader_for_text(fp, encoding):
+    if isinstance(fp.read(0), bytes):
+        fp = io.TextIOWrapper(io.BufferedReader(fp), encoding)
+    return fp
+
+
+def _wrap_writer_for_text(fp, encoding):
+    try:
+        fp.write('')
+    except TypeError:
+        fp = io.TextIOWrapper(fp, encoding)
+    return fp
+
+
+class JSONEncoder(_json.JSONEncoder):
+    """The default Flask JSON encoder.  This one extends the default simplejson
+    encoder by also supporting ``datetime`` objects, ``UUID`` as well as
+    ``Markup`` objects which are serialized as RFC 822 datetime strings (same
+    as the HTTP date format).  In order to support more data types override the
+    :meth:`default` method.
+    """
+
+    def default(self, o):
+        """Implement this method in a subclass such that it returns a
+        serializable object for ``o``, or calls the base implementation (to
+        raise a :exc:`TypeError`).
+
+        For example, to support arbitrary iterators, you could implement
+        default like this::
+
+            def default(self, o):
+                try:
+                    iterable = iter(o)
+                except TypeError:
+                    pass
+                else:
+                    return list(iterable)
+                return JSONEncoder.default(self, o)
+        """
+        if isinstance(o, datetime):
+            return http_date(o.utctimetuple())
+        if isinstance(o, date):
+            return http_date(o.timetuple())
+        if isinstance(o, uuid.UUID):
+            return str(o)
+        if hasattr(o, '__html__'):
+            return text_type(o.__html__())
+        return _json.JSONEncoder.default(self, o)
+
+
+class JSONDecoder(_json.JSONDecoder):
+    """The default JSON decoder.  This one does not change the behavior from
+    the default simplejson decoder.  Consult the :mod:`json` documentation
+    for more information.  This decoder is not only used for the load
+    functions of this module but also :attr:`~flask.Request`.
+    """
+
+
+def _dump_arg_defaults(kwargs, app=None):
+    """Inject default arguments for dump functions."""
+    if app is None:
+        app = current_app
+
+    if app:
+        bp = app.blueprints.get(request.blueprint) if request else None
+        kwargs.setdefault(
+            'cls', bp.json_encoder if bp and bp.json_encoder else app.json_encoder
+        )
+
+        if not app.config['JSON_AS_ASCII']:
+            kwargs.setdefault('ensure_ascii', False)
+
+        kwargs.setdefault('sort_keys', app.config['JSON_SORT_KEYS'])
+    else:
+        kwargs.setdefault('sort_keys', True)
+        kwargs.setdefault('cls', JSONEncoder)
+
+
+def _load_arg_defaults(kwargs, app=None):
+    """Inject default arguments for load functions."""
+    if app is None:
+        app = current_app
+
+    if app:
+        bp = app.blueprints.get(request.blueprint) if request else None
+        kwargs.setdefault(
+            'cls',
+            bp.json_decoder if bp and bp.json_decoder
+                else app.json_decoder
+        )
+    else:
+        kwargs.setdefault('cls', JSONDecoder)
+
+
+def detect_encoding(data):
+    """Detect which UTF codec was used to encode the given bytes.
+
+    The latest JSON standard (:rfc:`8259`) suggests that only UTF-8 is
+    accepted. Older documents allowed 8, 16, or 32. 16 and 32 can be big
+    or little endian. Some editors or libraries may prepend a BOM.
+
+    :param data: Bytes in unknown UTF encoding.
+    :return: UTF encoding name
+    """
+    head = data[:4]
+
+    if head[:3] == codecs.BOM_UTF8:
+        return 'utf-8-sig'
+
+    if b'\x00' not in head:
+        return 'utf-8'
+
+    if head in (codecs.BOM_UTF32_BE, codecs.BOM_UTF32_LE):
+        return 'utf-32'
+
+    if head[:2] in (codecs.BOM_UTF16_BE, codecs.BOM_UTF16_LE):
+        return 'utf-16'
+
+    if len(head) == 4:
+        if head[:3] == b'\x00\x00\x00':
+            return 'utf-32-be'
+
+        if head[::2] == b'\x00\x00':
+            return 'utf-16-be'
+
+        if head[1:] == b'\x00\x00\x00':
+            return 'utf-32-le'
+
+        if head[1::2] == b'\x00\x00':
+            return 'utf-16-le'
+
+    if len(head) == 2:
+        return 'utf-16-be' if head.startswith(b'\x00') else 'utf-16-le'
+
+    return 'utf-8'
+
+
+def dumps(obj, app=None, **kwargs):
+    """Serialize ``obj`` to a JSON-formatted string. If there is an
+    app context pushed, use the current app's configured encoder
+    (:attr:`~flask.Flask.json_encoder`), or fall back to the default
+    :class:`JSONEncoder`.
+
+    Takes the same arguments as the built-in :func:`json.dumps`, and
+    does some extra configuration based on the application. If the
+    simplejson package is installed, it is preferred.
+
+    :param obj: Object to serialize to JSON.
+    :param app: App instance to use to configure the JSON encoder.
+        Uses ``current_app`` if not given, and falls back to the default
+        encoder when not in an app context.
+    :param kwargs: Extra arguments passed to :func:`json.dumps`.
+
+    .. versionchanged:: 1.0.3
+
+        ``app`` can be passed directly, rather than requiring an app
+        context for configuration.
+    """
+    _dump_arg_defaults(kwargs, app=app)
+    encoding = kwargs.pop('encoding', None)
+    rv = _json.dumps(obj, **kwargs)
+    if encoding is not None and isinstance(rv, text_type):
+        rv = rv.encode(encoding)
+    return rv
+
+
+def dump(obj, fp, app=None, **kwargs):
+    """Like :func:`dumps` but writes into a file object."""
+    _dump_arg_defaults(kwargs, app=app)
+    encoding = kwargs.pop('encoding', None)
+    if encoding is not None:
+        fp = _wrap_writer_for_text(fp, encoding)
+    _json.dump(obj, fp, **kwargs)
+
+
+def loads(s, app=None, **kwargs):
+    """Deserialize an object from a JSON-formatted string ``s``. If
+    there is an app context pushed, use the current app's configured
+    decoder (:attr:`~flask.Flask.json_decoder`), or fall back to the
+    default :class:`JSONDecoder`.
+
+    Takes the same arguments as the built-in :func:`json.loads`, and
+    does some extra configuration based on the application. If the
+    simplejson package is installed, it is preferred.
+
+    :param s: JSON string to deserialize.
+    :param app: App instance to use to configure the JSON decoder.
+        Uses ``current_app`` if not given, and falls back to the default
+        encoder when not in an app context.
+    :param kwargs: Extra arguments passed to :func:`json.dumps`.
+
+    .. versionchanged:: 1.0.3
+
+        ``app`` can be passed directly, rather than requiring an app
+        context for configuration.
+    """
+    _load_arg_defaults(kwargs, app=app)
+    if isinstance(s, bytes):
+        encoding = kwargs.pop('encoding', None)
+        if encoding is None:
+            encoding = detect_encoding(s)
+        s = s.decode(encoding)
+    return _json.loads(s, **kwargs)
+
+
+def load(fp, app=None, **kwargs):
+    """Like :func:`loads` but reads from a file object."""
+    _load_arg_defaults(kwargs, app=app)
+    if not PY2:
+        fp = _wrap_reader_for_text(fp, kwargs.pop('encoding', None) or 'utf-8')
+    return _json.load(fp, **kwargs)
+
+
+def htmlsafe_dumps(obj, **kwargs):
+    """Works exactly like :func:`dumps` but is safe for use in ``<script>``
+    tags.  It accepts the same arguments and returns a JSON string.  Note that
+    this is available in templates through the ``|tojson`` filter which will
+    also mark the result as safe.  Due to how this function escapes certain
+    characters this is safe even if used outside of ``<script>`` tags.
+
+    The following characters are escaped in strings:
+
+    -   ``<``
+    -   ``>``
+    -   ``&``
+    -   ``'``
+
+    This makes it safe to embed such strings in any place in HTML with the
+    notable exception of double quoted attributes.  In that case single
+    quote your attributes or HTML escape it in addition.
+
+    .. versionchanged:: 0.10
+       This function's return value is now always safe for HTML usage, even
+       if outside of script tags or if used in XHTML.  This rule does not
+       hold true when using this function in HTML attributes that are double
+       quoted.  Always single quote attributes if you use the ``|tojson``
+       filter.  Alternatively use ``|tojson|forceescape``.
+    """
+    rv = dumps(obj, **kwargs) \
+        .replace(u'<', u'\\u003c') \
+        .replace(u'>', u'\\u003e') \
+        .replace(u'&', u'\\u0026') \
+        .replace(u"'", u'\\u0027')
+    if not _slash_escape:
+        rv = rv.replace('\\/', '/')
+    return rv
+
+
+def htmlsafe_dump(obj, fp, **kwargs):
+    """Like :func:`htmlsafe_dumps` but writes into a file object."""
+    fp.write(text_type(htmlsafe_dumps(obj, **kwargs)))
+
+
+def jsonify(*args, **kwargs):
+    """This function wraps :func:`dumps` to add a few enhancements that make
+    life easier.  It turns the JSON output into a :class:`~flask.Response`
+    object with the :mimetype:`application/json` mimetype.  For convenience, it
+    also converts multiple arguments into an array or multiple keyword arguments
+    into a dict.  This means that both ``jsonify(1,2,3)`` and
+    ``jsonify([1,2,3])`` serialize to ``[1,2,3]``.
+
+    For clarity, the JSON serialization behavior has the following differences
+    from :func:`dumps`:
+
+    1. Single argument: Passed straight through to :func:`dumps`.
+    2. Multiple arguments: Converted to an array before being passed to
+       :func:`dumps`.
+    3. Multiple keyword arguments: Converted to a dict before being passed to
+       :func:`dumps`.
+    4. Both args and kwargs: Behavior undefined and will throw an exception.
+
+    Example usage::
+
+        from flask import jsonify
+
+        @app.route('/_get_current_user')
+        def get_current_user():
+            return jsonify(username=g.user.username,
+                           email=g.user.email,
+                           id=g.user.id)
+
+    This will send a JSON response like this to the browser::
+
+        {
+            "username": "admin",
+            "email": "admin@localhost",
+            "id": 42
+        }
+
+
+    .. versionchanged:: 0.11
+       Added support for serializing top-level arrays. This introduces a
+       security risk in ancient browsers. See :ref:`json-security` for details.
+
+    This function's response will be pretty printed if the
+    ``JSONIFY_PRETTYPRINT_REGULAR`` config parameter is set to True or the
+    Flask app is running in debug mode. Compressed (not pretty) formatting
+    currently means no indents and no spaces after separators.
+
+    .. versionadded:: 0.2
+    """
+
+    indent = None
+    separators = (',', ':')
+
+    if current_app.config['JSONIFY_PRETTYPRINT_REGULAR'] or current_app.debug:
+        indent = 2
+        separators = (', ', ': ')
+
+    if args and kwargs:
+        raise TypeError('jsonify() behavior undefined when passed both args and kwargs')
+    elif len(args) == 1:  # single args are passed directly to dumps()
+        data = args[0]
+    else:
+        data = args or kwargs
+
+    return current_app.response_class(
+        dumps(data, indent=indent, separators=separators) + '\n',
+        mimetype=current_app.config['JSONIFY_MIMETYPE']
+    )
+
+
+def tojson_filter(obj, **kwargs):
+    return Markup(htmlsafe_dumps(obj, **kwargs))
diff --git a/python/flask/json/tag.py b/python/flask/json/tag.py
new file mode 100644
index 0000000..11c966c
--- /dev/null
+++ b/python/flask/json/tag.py
@@ -0,0 +1,300 @@
+# -*- coding: utf-8 -*-
+"""
+Tagged JSON
+~~~~~~~~~~~
+
+A compact representation for lossless serialization of non-standard JSON types.
+:class:`~flask.sessions.SecureCookieSessionInterface` uses this to serialize
+the session data, but it may be useful in other places. It can be extended to
+support other types.
+
+.. autoclass:: TaggedJSONSerializer
+    :members:
+
+.. autoclass:: JSONTag
+    :members:
+
+Let's seen an example that adds support for :class:`~collections.OrderedDict`.
+Dicts don't have an order in Python or JSON, so to handle this we will dump
+the items as a list of ``[key, value]`` pairs. Subclass :class:`JSONTag` and
+give it the new key ``' od'`` to identify the type. The session serializer
+processes dicts first, so insert the new tag at the front of the order since
+``OrderedDict`` must be processed before ``dict``. ::
+
+    from flask.json.tag import JSONTag
+
+    class TagOrderedDict(JSONTag):
+        __slots__ = ('serializer',)
+        key = ' od'
+
+        def check(self, value):
+            return isinstance(value, OrderedDict)
+
+        def to_json(self, value):
+            return [[k, self.serializer.tag(v)] for k, v in iteritems(value)]
+
+        def to_python(self, value):
+            return OrderedDict(value)
+
+    app.session_interface.serializer.register(TagOrderedDict, index=0)
+
+:copyright: © 2010 by the Pallets team.
+:license: BSD, see LICENSE for more details.
+"""
+
+from base64 import b64decode, b64encode
+from datetime import datetime
+from uuid import UUID
+
+from jinja2 import Markup
+from werkzeug.http import http_date, parse_date
+
+from flask._compat import iteritems, text_type
+from flask.json import dumps, loads
+
+
+class JSONTag(object):
+    """Base class for defining type tags for :class:`TaggedJSONSerializer`."""
+
+    __slots__ = ('serializer',)
+
+    #: The tag to mark the serialized object with. If ``None``, this tag is
+    #: only used as an intermediate step during tagging.
+    key = None
+
+    def __init__(self, serializer):
+        """Create a tagger for the given serializer."""
+        self.serializer = serializer
+
+    def check(self, value):
+        """Check if the given value should be tagged by this tag."""
+        raise NotImplementedError
+
+    def to_json(self, value):
+        """Convert the Python object to an object that is a valid JSON type.
+        The tag will be added later."""
+        raise NotImplementedError
+
+    def to_python(self, value):
+        """Convert the JSON representation back to the correct type. The tag
+        will already be removed."""
+        raise NotImplementedError
+
+    def tag(self, value):
+        """Convert the value to a valid JSON type and add the tag structure
+        around it."""
+        return {self.key: self.to_json(value)}
+
+
+class TagDict(JSONTag):
+    """Tag for 1-item dicts whose only key matches a registered tag.
+
+    Internally, the dict key is suffixed with `__`, and the suffix is removed
+    when deserializing.
+    """
+
+    __slots__ = ()
+    key = ' di'
+
+    def check(self, value):
+        return (
+            isinstance(value, dict)
+            and len(value) == 1
+            and next(iter(value)) in self.serializer.tags
+        )
+
+    def to_json(self, value):
+        key = next(iter(value))
+        return {key + '__': self.serializer.tag(value[key])}
+
+    def to_python(self, value):
+        key = next(iter(value))
+        return {key[:-2]: value[key]}
+
+
+class PassDict(JSONTag):
+    __slots__ = ()
+
+    def check(self, value):
+        return isinstance(value, dict)
+
+    def to_json(self, value):
+        # JSON objects may only have string keys, so don't bother tagging the
+        # key here.
+        return dict((k, self.serializer.tag(v)) for k, v in iteritems(value))
+
+    tag = to_json
+
+
+class TagTuple(JSONTag):
+    __slots__ = ()
+    key = ' t'
+
+    def check(self, value):
+        return isinstance(value, tuple)
+
+    def to_json(self, value):
+        return [self.serializer.tag(item) for item in value]
+
+    def to_python(self, value):
+        return tuple(value)
+
+
+class PassList(JSONTag):
+    __slots__ = ()
+
+    def check(self, value):
+        return isinstance(value, list)
+
+    def to_json(self, value):
+        return [self.serializer.tag(item) for item in value]
+
+    tag = to_json
+
+
+class TagBytes(JSONTag):
+    __slots__ = ()
+    key = ' b'
+
+    def check(self, value):
+        return isinstance(value, bytes)
+
+    def to_json(self, value):
+        return b64encode(value).decode('ascii')
+
+    def to_python(self, value):
+        return b64decode(value)
+
+
+class TagMarkup(JSONTag):
+    """Serialize anything matching the :class:`~flask.Markup` API by
+    having a ``__html__`` method to the result of that method. Always
+    deserializes to an instance of :class:`~flask.Markup`."""
+
+    __slots__ = ()
+    key = ' m'
+
+    def check(self, value):
+        return callable(getattr(value, '__html__', None))
+
+    def to_json(self, value):
+        return text_type(value.__html__())
+
+    def to_python(self, value):
+        return Markup(value)
+
+
+class TagUUID(JSONTag):
+    __slots__ = ()
+    key = ' u'
+
+    def check(self, value):
+        return isinstance(value, UUID)
+
+    def to_json(self, value):
+        return value.hex
+
+    def to_python(self, value):
+        return UUID(value)
+
+
+class TagDateTime(JSONTag):
+    __slots__ = ()
+    key = ' d'
+
+    def check(self, value):
+        return isinstance(value, datetime)
+
+    def to_json(self, value):
+        return http_date(value)
+
+    def to_python(self, value):
+        return parse_date(value)
+
+
+class TaggedJSONSerializer(object):
+    """Serializer that uses a tag system to compactly represent objects that
+    are not JSON types. Passed as the intermediate serializer to
+    :class:`itsdangerous.Serializer`.
+
+    The following extra types are supported:
+
+    * :class:`dict`
+    * :class:`tuple`
+    * :class:`bytes`
+    * :class:`~flask.Markup`
+    * :class:`~uuid.UUID`
+    * :class:`~datetime.datetime`
+    """
+
+    __slots__ = ('tags', 'order')
+
+    #: Tag classes to bind when creating the serializer. Other tags can be
+    #: added later using :meth:`~register`.
+    default_tags = [
+        TagDict, PassDict, TagTuple, PassList, TagBytes, TagMarkup, TagUUID,
+        TagDateTime,
+    ]
+
+    def __init__(self):
+        self.tags = {}
+        self.order = []
+
+        for cls in self.default_tags:
+            self.register(cls)
+
+    def register(self, tag_class, force=False, index=None):
+        """Register a new tag with this serializer.
+
+        :param tag_class: tag class to register. Will be instantiated with this
+            serializer instance.
+        :param force: overwrite an existing tag. If false (default), a
+            :exc:`KeyError` is raised.
+        :param index: index to insert the new tag in the tag order. Useful when
+            the new tag is a special case of an existing tag. If ``None``
+            (default), the tag is appended to the end of the order.
+
+        :raise KeyError: if the tag key is already registered and ``force`` is
+            not true.
+        """
+        tag = tag_class(self)
+        key = tag.key
+
+        if key is not None:
+            if not force and key in self.tags:
+                raise KeyError("Tag '{0}' is already registered.".format(key))
+
+            self.tags[key] = tag
+
+        if index is None:
+            self.order.append(tag)
+        else:
+            self.order.insert(index, tag)
+
+    def tag(self, value):
+        """Convert a value to a tagged representation if necessary."""
+        for tag in self.order:
+            if tag.check(value):
+                return tag.tag(value)
+
+        return value
+
+    def untag(self, value):
+        """Convert a tagged representation back to the original type."""
+        if len(value) != 1:
+            return value
+
+        key = next(iter(value))
+
+        if key not in self.tags:
+            return value
+
+        return self.tags[key].to_python(value[key])
+
+    def dumps(self, value):
+        """Tag the value and dump it to a compact JSON string."""
+        return dumps(self.tag(value), separators=(',', ':'))
+
+    def loads(self, value):
+        """Load data from a JSON string and deserialized any tagged objects."""
+        return loads(value, object_hook=self.untag)
diff --git a/python/flask/logging.py b/python/flask/logging.py
new file mode 100644
index 0000000..389c2c2
--- /dev/null
+++ b/python/flask/logging.py
@@ -0,0 +1,78 @@
+# -*- coding: utf-8 -*-
+"""
+flask.logging
+~~~~~~~~~~~~~
+
+:copyright: © 2010 by the Pallets team.
+:license: BSD, see LICENSE for more details.
+"""
+
+from __future__ import absolute_import
+
+import logging
+import sys
+
+from werkzeug.local import LocalProxy
+
+from .globals import request
+
+
+@LocalProxy
+def wsgi_errors_stream():
+    """Find the most appropriate error stream for the application. If a request
+    is active, log to ``wsgi.errors``, otherwise use ``sys.stderr``.
+
+    If you configure your own :class:`logging.StreamHandler`, you may want to
+    use this for the stream. If you are using file or dict configuration and
+    can't import this directly, you can refer to it as
+    ``ext://flask.logging.wsgi_errors_stream``.
+    """
+    return request.environ['wsgi.errors'] if request else sys.stderr
+
+
+def has_level_handler(logger):
+    """Check if there is a handler in the logging chain that will handle the
+    given logger's :meth:`effective level <~logging.Logger.getEffectiveLevel>`.
+    """
+    level = logger.getEffectiveLevel()
+    current = logger
+
+    while current:
+        if any(handler.level <= level for handler in current.handlers):
+            return True
+
+        if not current.propagate:
+            break
+
+        current = current.parent
+
+    return False
+
+
+#: Log messages to :func:`~flask.logging.wsgi_errors_stream` with the format
+#: ``[%(asctime)s] %(levelname)s in %(module)s: %(message)s``.
+default_handler = logging.StreamHandler(wsgi_errors_stream)
+default_handler.setFormatter(logging.Formatter(
+    '[%(asctime)s] %(levelname)s in %(module)s: %(message)s'
+))
+
+
+def create_logger(app):
+    """Get the ``'flask.app'`` logger and configure it if needed.
+
+    When :attr:`~flask.Flask.debug` is enabled, set the logger level to
+    :data:`logging.DEBUG` if it is not set.
+
+    If there is no handler for the logger's effective level, add a
+    :class:`~logging.StreamHandler` for
+    :func:`~flask.logging.wsgi_errors_stream` with a basic format.
+    """
+    logger = logging.getLogger('flask.app')
+
+    if app.debug and logger.level == logging.NOTSET:
+        logger.setLevel(logging.DEBUG)
+
+    if not has_level_handler(logger):
+        logger.addHandler(default_handler)
+
+    return logger
diff --git a/python/flask/sessions.py b/python/flask/sessions.py
new file mode 100644
index 0000000..c8b7d4e
--- /dev/null
+++ b/python/flask/sessions.py
@@ -0,0 +1,385 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.sessions
+    ~~~~~~~~~~~~~~
+
+    Implements cookie based sessions based on itsdangerous.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import hashlib
+import warnings
+from datetime import datetime
+
+from itsdangerous import BadSignature, URLSafeTimedSerializer
+from werkzeug.datastructures import CallbackDict
+
+from flask._compat import collections_abc
+from flask.helpers import is_ip, total_seconds
+from flask.json.tag import TaggedJSONSerializer
+
+
+class SessionMixin(collections_abc.MutableMapping):
+    """Expands a basic dictionary with session attributes."""
+
+    @property
+    def permanent(self):
+        """This reflects the ``'_permanent'`` key in the dict."""
+        return self.get('_permanent', False)
+
+    @permanent.setter
+    def permanent(self, value):
+        self['_permanent'] = bool(value)
+
+    #: Some implementations can detect whether a session is newly
+    #: created, but that is not guaranteed. Use with caution. The mixin
+    # default is hard-coded ``False``.
+    new = False
+
+    #: Some implementations can detect changes to the session and set
+    #: this when that happens. The mixin default is hard coded to
+    #: ``True``.
+    modified = True
+
+    #: Some implementations can detect when session data is read or
+    #: written and set this when that happens. The mixin default is hard
+    #: coded to ``True``.
+    accessed = True
+
+
+class SecureCookieSession(CallbackDict, SessionMixin):
+    """Base class for sessions based on signed cookies.
+
+    This session backend will set the :attr:`modified` and
+    :attr:`accessed` attributes. It cannot reliably track whether a
+    session is new (vs. empty), so :attr:`new` remains hard coded to
+    ``False``.
+    """
+
+    #: When data is changed, this is set to ``True``. Only the session
+    #: dictionary itself is tracked; if the session contains mutable
+    #: data (for example a nested dict) then this must be set to
+    #: ``True`` manually when modifying that data. The session cookie
+    #: will only be written to the response if this is ``True``.
+    modified = False
+
+    #: When data is read or written, this is set to ``True``. Used by
+    # :class:`.SecureCookieSessionInterface` to add a ``Vary: Cookie``
+    #: header, which allows caching proxies to cache different pages for
+    #: different users.
+    accessed = False
+
+    def __init__(self, initial=None):
+        def on_update(self):
+            self.modified = True
+            self.accessed = True
+
+        super(SecureCookieSession, self).__init__(initial, on_update)
+
+    def __getitem__(self, key):
+        self.accessed = True
+        return super(SecureCookieSession, self).__getitem__(key)
+
+    def get(self, key, default=None):
+        self.accessed = True
+        return super(SecureCookieSession, self).get(key, default)
+
+    def setdefault(self, key, default=None):
+        self.accessed = True
+        return super(SecureCookieSession, self).setdefault(key, default)
+
+
+class NullSession(SecureCookieSession):
+    """Class used to generate nicer error messages if sessions are not
+    available.  Will still allow read-only access to the empty session
+    but fail on setting.
+    """
+
+    def _fail(self, *args, **kwargs):
+        raise RuntimeError('The session is unavailable because no secret '
+                           'key was set.  Set the secret_key on the '
+                           'application to something unique and secret.')
+    __setitem__ = __delitem__ = clear = pop = popitem = \
+        update = setdefault = _fail
+    del _fail
+
+
+class SessionInterface(object):
+    """The basic interface you have to implement in order to replace the
+    default session interface which uses werkzeug's securecookie
+    implementation.  The only methods you have to implement are
+    :meth:`open_session` and :meth:`save_session`, the others have
+    useful defaults which you don't need to change.
+
+    The session object returned by the :meth:`open_session` method has to
+    provide a dictionary like interface plus the properties and methods
+    from the :class:`SessionMixin`.  We recommend just subclassing a dict
+    and adding that mixin::
+
+        class Session(dict, SessionMixin):
+            pass
+
+    If :meth:`open_session` returns ``None`` Flask will call into
+    :meth:`make_null_session` to create a session that acts as replacement
+    if the session support cannot work because some requirement is not
+    fulfilled.  The default :class:`NullSession` class that is created
+    will complain that the secret key was not set.
+
+    To replace the session interface on an application all you have to do
+    is to assign :attr:`flask.Flask.session_interface`::
+
+        app = Flask(__name__)
+        app.session_interface = MySessionInterface()
+
+    .. versionadded:: 0.8
+    """
+
+    #: :meth:`make_null_session` will look here for the class that should
+    #: be created when a null session is requested.  Likewise the
+    #: :meth:`is_null_session` method will perform a typecheck against
+    #: this type.
+    null_session_class = NullSession
+
+    #: A flag that indicates if the session interface is pickle based.
+    #: This can be used by Flask extensions to make a decision in regards
+    #: to how to deal with the session object.
+    #:
+    #: .. versionadded:: 0.10
+    pickle_based = False
+
+    def make_null_session(self, app):
+        """Creates a null session which acts as a replacement object if the
+        real session support could not be loaded due to a configuration
+        error.  This mainly aids the user experience because the job of the
+        null session is to still support lookup without complaining but
+        modifications are answered with a helpful error message of what
+        failed.
+
+        This creates an instance of :attr:`null_session_class` by default.
+        """
+        return self.null_session_class()
+
+    def is_null_session(self, obj):
+        """Checks if a given object is a null session.  Null sessions are
+        not asked to be saved.
+
+        This checks if the object is an instance of :attr:`null_session_class`
+        by default.
+        """
+        return isinstance(obj, self.null_session_class)
+
+    def get_cookie_domain(self, app):
+        """Returns the domain that should be set for the session cookie.
+
+        Uses ``SESSION_COOKIE_DOMAIN`` if it is configured, otherwise
+        falls back to detecting the domain based on ``SERVER_NAME``.
+
+        Once detected (or if not set at all), ``SESSION_COOKIE_DOMAIN`` is
+        updated to avoid re-running the logic.
+        """
+
+        rv = app.config['SESSION_COOKIE_DOMAIN']
+
+        # set explicitly, or cached from SERVER_NAME detection
+        # if False, return None
+        if rv is not None:
+            return rv if rv else None
+
+        rv = app.config['SERVER_NAME']
+
+        # server name not set, cache False to return none next time
+        if not rv:
+            app.config['SESSION_COOKIE_DOMAIN'] = False
+            return None
+
+        # chop off the port which is usually not supported by browsers
+        # remove any leading '.' since we'll add that later
+        rv = rv.rsplit(':', 1)[0].lstrip('.')
+
+        if '.' not in rv:
+            # Chrome doesn't allow names without a '.'
+            # this should only come up with localhost
+            # hack around this by not setting the name, and show a warning
+            warnings.warn(
+                '"{rv}" is not a valid cookie domain, it must contain a ".".'
+                ' Add an entry to your hosts file, for example'
+                ' "{rv}.localdomain", and use that instead.'.format(rv=rv)
+            )
+            app.config['SESSION_COOKIE_DOMAIN'] = False
+            return None
+
+        ip = is_ip(rv)
+
+        if ip:
+            warnings.warn(
+                'The session cookie domain is an IP address. This may not work'
+                ' as intended in some browsers. Add an entry to your hosts'
+                ' file, for example "localhost.localdomain", and use that'
+                ' instead.'
+            )
+
+        # if this is not an ip and app is mounted at the root, allow subdomain
+        # matching by adding a '.' prefix
+        if self.get_cookie_path(app) == '/' and not ip:
+            rv = '.' + rv
+
+        app.config['SESSION_COOKIE_DOMAIN'] = rv
+        return rv
+
+    def get_cookie_path(self, app):
+        """Returns the path for which the cookie should be valid.  The
+        default implementation uses the value from the ``SESSION_COOKIE_PATH``
+        config var if it's set, and falls back to ``APPLICATION_ROOT`` or
+        uses ``/`` if it's ``None``.
+        """
+        return app.config['SESSION_COOKIE_PATH'] \
+               or app.config['APPLICATION_ROOT']
+
+    def get_cookie_httponly(self, app):
+        """Returns True if the session cookie should be httponly.  This
+        currently just returns the value of the ``SESSION_COOKIE_HTTPONLY``
+        config var.
+        """
+        return app.config['SESSION_COOKIE_HTTPONLY']
+
+    def get_cookie_secure(self, app):
+        """Returns True if the cookie should be secure.  This currently
+        just returns the value of the ``SESSION_COOKIE_SECURE`` setting.
+        """
+        return app.config['SESSION_COOKIE_SECURE']
+
+    def get_cookie_samesite(self, app):
+        """Return ``'Strict'`` or ``'Lax'`` if the cookie should use the
+        ``SameSite`` attribute. This currently just returns the value of
+        the :data:`SESSION_COOKIE_SAMESITE` setting.
+        """
+        return app.config['SESSION_COOKIE_SAMESITE']
+
+    def get_expiration_time(self, app, session):
+        """A helper method that returns an expiration date for the session
+        or ``None`` if the session is linked to the browser session.  The
+        default implementation returns now + the permanent session
+        lifetime configured on the application.
+        """
+        if session.permanent:
+            return datetime.utcnow() + app.permanent_session_lifetime
+
+    def should_set_cookie(self, app, session):
+        """Used by session backends to determine if a ``Set-Cookie`` header
+        should be set for this session cookie for this response. If the session
+        has been modified, the cookie is set. If the session is permanent and
+        the ``SESSION_REFRESH_EACH_REQUEST`` config is true, the cookie is
+        always set.
+
+        This check is usually skipped if the session was deleted.
+
+        .. versionadded:: 0.11
+        """
+
+        return session.modified or (
+            session.permanent and app.config['SESSION_REFRESH_EACH_REQUEST']
+        )
+
+    def open_session(self, app, request):
+        """This method has to be implemented and must either return ``None``
+        in case the loading failed because of a configuration error or an
+        instance of a session object which implements a dictionary like
+        interface + the methods and attributes on :class:`SessionMixin`.
+        """
+        raise NotImplementedError()
+
+    def save_session(self, app, session, response):
+        """This is called for actual sessions returned by :meth:`open_session`
+        at the end of the request.  This is still called during a request
+        context so if you absolutely need access to the request you can do
+        that.
+        """
+        raise NotImplementedError()
+
+
+session_json_serializer = TaggedJSONSerializer()
+
+
+class SecureCookieSessionInterface(SessionInterface):
+    """The default session interface that stores sessions in signed cookies
+    through the :mod:`itsdangerous` module.
+    """
+    #: the salt that should be applied on top of the secret key for the
+    #: signing of cookie based sessions.
+    salt = 'cookie-session'
+    #: the hash function to use for the signature.  The default is sha1
+    digest_method = staticmethod(hashlib.sha1)
+    #: the name of the itsdangerous supported key derivation.  The default
+    #: is hmac.
+    key_derivation = 'hmac'
+    #: A python serializer for the payload.  The default is a compact
+    #: JSON derived serializer with support for some extra Python types
+    #: such as datetime objects or tuples.
+    serializer = session_json_serializer
+    session_class = SecureCookieSession
+
+    def get_signing_serializer(self, app):
+        if not app.secret_key:
+            return None
+        signer_kwargs = dict(
+            key_derivation=self.key_derivation,
+            digest_method=self.digest_method
+        )
+        return URLSafeTimedSerializer(app.secret_key, salt=self.salt,
+                                      serializer=self.serializer,
+                                      signer_kwargs=signer_kwargs)
+
+    def open_session(self, app, request):
+        s = self.get_signing_serializer(app)
+        if s is None:
+            return None
+        val = request.cookies.get(app.session_cookie_name)
+        if not val:
+            return self.session_class()
+        max_age = total_seconds(app.permanent_session_lifetime)
+        try:
+            data = s.loads(val, max_age=max_age)
+            return self.session_class(data)
+        except BadSignature:
+            return self.session_class()
+
+    def save_session(self, app, session, response):
+        domain = self.get_cookie_domain(app)
+        path = self.get_cookie_path(app)
+
+        # If the session is modified to be empty, remove the cookie.
+        # If the session is empty, return without setting the cookie.
+        if not session:
+            if session.modified:
+                response.delete_cookie(
+                    app.session_cookie_name,
+                    domain=domain,
+                    path=path
+                )
+
+            return
+
+        # Add a "Vary: Cookie" header if the session was accessed at all.
+        if session.accessed:
+            response.vary.add('Cookie')
+
+        if not self.should_set_cookie(app, session):
+            return
+
+        httponly = self.get_cookie_httponly(app)
+        secure = self.get_cookie_secure(app)
+        samesite = self.get_cookie_samesite(app)
+        expires = self.get_expiration_time(app, session)
+        val = self.get_signing_serializer(app).dumps(dict(session))
+        response.set_cookie(
+            app.session_cookie_name,
+            val,
+            expires=expires,
+            httponly=httponly,
+            domain=domain,
+            path=path,
+            secure=secure,
+            samesite=samesite
+        )
diff --git a/python/flask/signals.py b/python/flask/signals.py
new file mode 100644
index 0000000..18f2630
--- /dev/null
+++ b/python/flask/signals.py
@@ -0,0 +1,57 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.signals
+    ~~~~~~~~~~~~~
+
+    Implements signals based on blinker if available, otherwise
+    falls silently back to a noop.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+signals_available = False
+try:
+    from blinker import Namespace
+    signals_available = True
+except ImportError:
+    class Namespace(object):
+        def signal(self, name, doc=None):
+            return _FakeSignal(name, doc)
+
+    class _FakeSignal(object):
+        """If blinker is unavailable, create a fake class with the same
+        interface that allows sending of signals but will fail with an
+        error on anything else.  Instead of doing anything on send, it
+        will just ignore the arguments and do nothing instead.
+        """
+
+        def __init__(self, name, doc=None):
+            self.name = name
+            self.__doc__ = doc
+        def _fail(self, *args, **kwargs):
+            raise RuntimeError('signalling support is unavailable '
+                               'because the blinker library is '
+                               'not installed.')
+        send = lambda *a, **kw: None
+        connect = disconnect = has_receivers_for = receivers_for = \
+            temporarily_connected_to = connected_to = _fail
+        del _fail
+
+# The namespace for code signals.  If you are not Flask code, do
+# not put signals in here.  Create your own namespace instead.
+_signals = Namespace()
+
+
+# Core signals.  For usage examples grep the source code or consult
+# the API documentation in docs/api.rst as well as docs/signals.rst
+template_rendered = _signals.signal('template-rendered')
+before_render_template = _signals.signal('before-render-template')
+request_started = _signals.signal('request-started')
+request_finished = _signals.signal('request-finished')
+request_tearing_down = _signals.signal('request-tearing-down')
+got_request_exception = _signals.signal('got-request-exception')
+appcontext_tearing_down = _signals.signal('appcontext-tearing-down')
+appcontext_pushed = _signals.signal('appcontext-pushed')
+appcontext_popped = _signals.signal('appcontext-popped')
+message_flashed = _signals.signal('message-flashed')
diff --git a/python/flask/templating.py b/python/flask/templating.py
new file mode 100644
index 0000000..0240200
--- /dev/null
+++ b/python/flask/templating.py
@@ -0,0 +1,150 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.templating
+    ~~~~~~~~~~~~~~~~
+
+    Implements the bridge to Jinja2.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from jinja2 import BaseLoader, Environment as BaseEnvironment, \
+     TemplateNotFound
+
+from .globals import _request_ctx_stack, _app_ctx_stack
+from .signals import template_rendered, before_render_template
+
+
+def _default_template_ctx_processor():
+    """Default template context processor.  Injects `request`,
+    `session` and `g`.
+    """
+    reqctx = _request_ctx_stack.top
+    appctx = _app_ctx_stack.top
+    rv = {}
+    if appctx is not None:
+        rv['g'] = appctx.g
+    if reqctx is not None:
+        rv['request'] = reqctx.request
+        rv['session'] = reqctx.session
+    return rv
+
+
+class Environment(BaseEnvironment):
+    """Works like a regular Jinja2 environment but has some additional
+    knowledge of how Flask's blueprint works so that it can prepend the
+    name of the blueprint to referenced templates if necessary.
+    """
+
+    def __init__(self, app, **options):
+        if 'loader' not in options:
+            options['loader'] = app.create_global_jinja_loader()
+        BaseEnvironment.__init__(self, **options)
+        self.app = app
+
+
+class DispatchingJinjaLoader(BaseLoader):
+    """A loader that looks for templates in the application and all
+    the blueprint folders.
+    """
+
+    def __init__(self, app):
+        self.app = app
+
+    def get_source(self, environment, template):
+        if self.app.config['EXPLAIN_TEMPLATE_LOADING']:
+            return self._get_source_explained(environment, template)
+        return self._get_source_fast(environment, template)
+
+    def _get_source_explained(self, environment, template):
+        attempts = []
+        trv = None
+
+        for srcobj, loader in self._iter_loaders(template):
+            try:
+                rv = loader.get_source(environment, template)
+                if trv is None:
+                    trv = rv
+            except TemplateNotFound:
+                rv = None
+            attempts.append((loader, srcobj, rv))
+
+        from .debughelpers import explain_template_loading_attempts
+        explain_template_loading_attempts(self.app, template, attempts)
+
+        if trv is not None:
+            return trv
+        raise TemplateNotFound(template)
+
+    def _get_source_fast(self, environment, template):
+        for srcobj, loader in self._iter_loaders(template):
+            try:
+                return loader.get_source(environment, template)
+            except TemplateNotFound:
+                continue
+        raise TemplateNotFound(template)
+
+    def _iter_loaders(self, template):
+        loader = self.app.jinja_loader
+        if loader is not None:
+            yield self.app, loader
+
+        for blueprint in self.app.iter_blueprints():
+            loader = blueprint.jinja_loader
+            if loader is not None:
+                yield blueprint, loader
+
+    def list_templates(self):
+        result = set()
+        loader = self.app.jinja_loader
+        if loader is not None:
+            result.update(loader.list_templates())
+
+        for blueprint in self.app.iter_blueprints():
+            loader = blueprint.jinja_loader
+            if loader is not None:
+                for template in loader.list_templates():
+                    result.add(template)
+
+        return list(result)
+
+
+def _render(template, context, app):
+    """Renders the template and fires the signal"""
+
+    before_render_template.send(app, template=template, context=context)
+    rv = template.render(context)
+    template_rendered.send(app, template=template, context=context)
+    return rv
+
+
+def render_template(template_name_or_list, **context):
+    """Renders a template from the template folder with the given
+    context.
+
+    :param template_name_or_list: the name of the template to be
+                                  rendered, or an iterable with template names
+                                  the first one existing will be rendered
+    :param context: the variables that should be available in the
+                    context of the template.
+    """
+    ctx = _app_ctx_stack.top
+    ctx.app.update_template_context(context)
+    return _render(ctx.app.jinja_env.get_or_select_template(template_name_or_list),
+                   context, ctx.app)
+
+
+def render_template_string(source, **context):
+    """Renders a template from the given template source string
+    with the given context. Template variables will be autoescaped.
+
+    :param source: the source code of the template to be
+                   rendered
+    :param context: the variables that should be available in the
+                    context of the template.
+    """
+    ctx = _app_ctx_stack.top
+    ctx.app.update_template_context(context)
+    return _render(ctx.app.jinja_env.from_string(source),
+                   context, ctx.app)
diff --git a/python/flask/testing.py b/python/flask/testing.py
new file mode 100644
index 0000000..114c5cc
--- /dev/null
+++ b/python/flask/testing.py
@@ -0,0 +1,246 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.testing
+    ~~~~~~~~~~~~~
+
+    Implements test support helpers.  This module is lazily imported
+    and usually not used in production environments.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+import werkzeug
+from contextlib import contextmanager
+
+from click.testing import CliRunner
+from flask.cli import ScriptInfo
+from werkzeug.test import Client, EnvironBuilder
+from flask import _request_ctx_stack
+from flask.json import dumps as json_dumps
+from werkzeug.urls import url_parse
+
+
+def make_test_environ_builder(
+    app, path='/', base_url=None, subdomain=None, url_scheme=None,
+    *args, **kwargs
+):
+    """Create a :class:`~werkzeug.test.EnvironBuilder`, taking some
+    defaults from the application.
+
+    :param app: The Flask application to configure the environment from.
+    :param path: URL path being requested.
+    :param base_url: Base URL where the app is being served, which
+        ``path`` is relative to. If not given, built from
+        :data:`PREFERRED_URL_SCHEME`, ``subdomain``,
+        :data:`SERVER_NAME`, and :data:`APPLICATION_ROOT`.
+    :param subdomain: Subdomain name to append to :data:`SERVER_NAME`.
+    :param url_scheme: Scheme to use instead of
+        :data:`PREFERRED_URL_SCHEME`.
+    :param json: If given, this is serialized as JSON and passed as
+        ``data``. Also defaults ``content_type`` to
+        ``application/json``.
+    :param args: other positional arguments passed to
+        :class:`~werkzeug.test.EnvironBuilder`.
+    :param kwargs: other keyword arguments passed to
+        :class:`~werkzeug.test.EnvironBuilder`.
+    """
+
+    assert (
+        not (base_url or subdomain or url_scheme)
+        or (base_url is not None) != bool(subdomain or url_scheme)
+    ), 'Cannot pass "subdomain" or "url_scheme" with "base_url".'
+
+    if base_url is None:
+        http_host = app.config.get('SERVER_NAME') or 'localhost'
+        app_root = app.config['APPLICATION_ROOT']
+
+        if subdomain:
+            http_host = '{0}.{1}'.format(subdomain, http_host)
+
+        if url_scheme is None:
+            url_scheme = app.config['PREFERRED_URL_SCHEME']
+
+        url = url_parse(path)
+        base_url = '{scheme}://{netloc}/{path}'.format(
+            scheme=url.scheme or url_scheme,
+            netloc=url.netloc or http_host,
+            path=app_root.lstrip('/')
+        )
+        path = url.path
+
+        if url.query:
+            sep = b'?' if isinstance(url.query, bytes) else '?'
+            path += sep + url.query
+
+    # TODO use EnvironBuilder.json_dumps once we require Werkzeug 0.15
+    if 'json' in kwargs:
+        assert 'data' not in kwargs, "Client cannot provide both 'json' and 'data'."
+        kwargs['data'] = json_dumps(kwargs.pop('json'), app=app)
+
+        if 'content_type' not in kwargs:
+            kwargs['content_type'] = 'application/json'
+
+    return EnvironBuilder(path, base_url, *args, **kwargs)
+
+
+class FlaskClient(Client):
+    """Works like a regular Werkzeug test client but has some knowledge about
+    how Flask works to defer the cleanup of the request context stack to the
+    end of a ``with`` body when used in a ``with`` statement.  For general
+    information about how to use this class refer to
+    :class:`werkzeug.test.Client`.
+
+    .. versionchanged:: 0.12
+       `app.test_client()` includes preset default environment, which can be
+       set after instantiation of the `app.test_client()` object in
+       `client.environ_base`.
+
+    Basic usage is outlined in the :ref:`testing` chapter.
+    """
+
+    preserve_context = False
+
+    def __init__(self, *args, **kwargs):
+        super(FlaskClient, self).__init__(*args, **kwargs)
+        self.environ_base = {
+            "REMOTE_ADDR": "127.0.0.1",
+            "HTTP_USER_AGENT": "werkzeug/" + werkzeug.__version__
+        }
+
+    @contextmanager
+    def session_transaction(self, *args, **kwargs):
+        """When used in combination with a ``with`` statement this opens a
+        session transaction.  This can be used to modify the session that
+        the test client uses.  Once the ``with`` block is left the session is
+        stored back.
+
+        ::
+
+            with client.session_transaction() as session:
+                session['value'] = 42
+
+        Internally this is implemented by going through a temporary test
+        request context and since session handling could depend on
+        request variables this function accepts the same arguments as
+        :meth:`~flask.Flask.test_request_context` which are directly
+        passed through.
+        """
+        if self.cookie_jar is None:
+            raise RuntimeError('Session transactions only make sense '
+                               'with cookies enabled.')
+        app = self.application
+        environ_overrides = kwargs.setdefault('environ_overrides', {})
+        self.cookie_jar.inject_wsgi(environ_overrides)
+        outer_reqctx = _request_ctx_stack.top
+        with app.test_request_context(*args, **kwargs) as c:
+            session_interface = app.session_interface
+            sess = session_interface.open_session(app, c.request)
+            if sess is None:
+                raise RuntimeError('Session backend did not open a session. '
+                                   'Check the configuration')
+
+            # Since we have to open a new request context for the session
+            # handling we want to make sure that we hide out own context
+            # from the caller.  By pushing the original request context
+            # (or None) on top of this and popping it we get exactly that
+            # behavior.  It's important to not use the push and pop
+            # methods of the actual request context object since that would
+            # mean that cleanup handlers are called
+            _request_ctx_stack.push(outer_reqctx)
+            try:
+                yield sess
+            finally:
+                _request_ctx_stack.pop()
+
+            resp = app.response_class()
+            if not session_interface.is_null_session(sess):
+                session_interface.save_session(app, sess, resp)
+            headers = resp.get_wsgi_headers(c.request.environ)
+            self.cookie_jar.extract_wsgi(c.request.environ, headers)
+
+    def open(self, *args, **kwargs):
+        as_tuple = kwargs.pop('as_tuple', False)
+        buffered = kwargs.pop('buffered', False)
+        follow_redirects = kwargs.pop('follow_redirects', False)
+
+        if (
+            not kwargs and len(args) == 1
+            and isinstance(args[0], (EnvironBuilder, dict))
+        ):
+            environ = self.environ_base.copy()
+
+            if isinstance(args[0], EnvironBuilder):
+                environ.update(args[0].get_environ())
+            else:
+                environ.update(args[0])
+
+            environ['flask._preserve_context'] = self.preserve_context
+        else:
+            kwargs.setdefault('environ_overrides', {}) \
+                ['flask._preserve_context'] = self.preserve_context
+            kwargs.setdefault('environ_base', self.environ_base)
+            builder = make_test_environ_builder(
+                self.application, *args, **kwargs
+            )
+
+            try:
+                environ = builder.get_environ()
+            finally:
+                builder.close()
+
+        return Client.open(
+            self, environ,
+            as_tuple=as_tuple,
+            buffered=buffered,
+            follow_redirects=follow_redirects
+        )
+
+    def __enter__(self):
+        if self.preserve_context:
+            raise RuntimeError('Cannot nest client invocations')
+        self.preserve_context = True
+        return self
+
+    def __exit__(self, exc_type, exc_value, tb):
+        self.preserve_context = False
+
+        # on exit we want to clean up earlier.  Normally the request context
+        # stays preserved until the next request in the same thread comes
+        # in.  See RequestGlobals.push() for the general behavior.
+        top = _request_ctx_stack.top
+        if top is not None and top.preserved:
+            top.pop()
+
+
+class FlaskCliRunner(CliRunner):
+    """A :class:`~click.testing.CliRunner` for testing a Flask app's
+    CLI commands. Typically created using
+    :meth:`~flask.Flask.test_cli_runner`. See :ref:`testing-cli`.
+    """
+    def __init__(self, app, **kwargs):
+        self.app = app
+        super(FlaskCliRunner, self).__init__(**kwargs)
+
+    def invoke(self, cli=None, args=None, **kwargs):
+        """Invokes a CLI command in an isolated environment. See
+        :meth:`CliRunner.invoke <click.testing.CliRunner.invoke>` for
+        full method documentation. See :ref:`testing-cli` for examples.
+
+        If the ``obj`` argument is not given, passes an instance of
+        :class:`~flask.cli.ScriptInfo` that knows how to load the Flask
+        app being tested.
+
+        :param cli: Command object to invoke. Default is the app's
+            :attr:`~flask.app.Flask.cli` group.
+        :param args: List of strings to invoke the command with.
+
+        :return: a :class:`~click.testing.Result` object.
+        """
+        if cli is None:
+            cli = self.app.cli
+
+        if 'obj' not in kwargs:
+            kwargs['obj'] = ScriptInfo(create_app=lambda: self.app)
+
+        return super(FlaskCliRunner, self).invoke(cli, args, **kwargs)
diff --git a/python/flask/views.py b/python/flask/views.py
new file mode 100644
index 0000000..1f2c997
--- /dev/null
+++ b/python/flask/views.py
@@ -0,0 +1,158 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.views
+    ~~~~~~~~~~~
+
+    This module provides class-based views inspired by the ones in Django.
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from .globals import request
+from ._compat import with_metaclass
+
+
+http_method_funcs = frozenset(['get', 'post', 'head', 'options',
+                               'delete', 'put', 'trace', 'patch'])
+
+
+class View(object):
+    """Alternative way to use view functions.  A subclass has to implement
+    :meth:`dispatch_request` which is called with the view arguments from
+    the URL routing system.  If :attr:`methods` is provided the methods
+    do not have to be passed to the :meth:`~flask.Flask.add_url_rule`
+    method explicitly::
+
+        class MyView(View):
+            methods = ['GET']
+
+            def dispatch_request(self, name):
+                return 'Hello %s!' % name
+
+        app.add_url_rule('/hello/<name>', view_func=MyView.as_view('myview'))
+
+    When you want to decorate a pluggable view you will have to either do that
+    when the view function is created (by wrapping the return value of
+    :meth:`as_view`) or you can use the :attr:`decorators` attribute::
+
+        class SecretView(View):
+            methods = ['GET']
+            decorators = [superuser_required]
+
+            def dispatch_request(self):
+                ...
+
+    The decorators stored in the decorators list are applied one after another
+    when the view function is created.  Note that you can *not* use the class
+    based decorators since those would decorate the view class and not the
+    generated view function!
+    """
+
+    #: A list of methods this view can handle.
+    methods = None
+
+    #: Setting this disables or force-enables the automatic options handling.
+    provide_automatic_options = None
+
+    #: The canonical way to decorate class-based views is to decorate the
+    #: return value of as_view().  However since this moves parts of the
+    #: logic from the class declaration to the place where it's hooked
+    #: into the routing system.
+    #:
+    #: You can place one or more decorators in this list and whenever the
+    #: view function is created the result is automatically decorated.
+    #:
+    #: .. versionadded:: 0.8
+    decorators = ()
+
+    def dispatch_request(self):
+        """Subclasses have to override this method to implement the
+        actual view function code.  This method is called with all
+        the arguments from the URL rule.
+        """
+        raise NotImplementedError()
+
+    @classmethod
+    def as_view(cls, name, *class_args, **class_kwargs):
+        """Converts the class into an actual view function that can be used
+        with the routing system.  Internally this generates a function on the
+        fly which will instantiate the :class:`View` on each request and call
+        the :meth:`dispatch_request` method on it.
+
+        The arguments passed to :meth:`as_view` are forwarded to the
+        constructor of the class.
+        """
+        def view(*args, **kwargs):
+            self = view.view_class(*class_args, **class_kwargs)
+            return self.dispatch_request(*args, **kwargs)
+
+        if cls.decorators:
+            view.__name__ = name
+            view.__module__ = cls.__module__
+            for decorator in cls.decorators:
+                view = decorator(view)
+
+        # We attach the view class to the view function for two reasons:
+        # first of all it allows us to easily figure out what class-based
+        # view this thing came from, secondly it's also used for instantiating
+        # the view class so you can actually replace it with something else
+        # for testing purposes and debugging.
+        view.view_class = cls
+        view.__name__ = name
+        view.__doc__ = cls.__doc__
+        view.__module__ = cls.__module__
+        view.methods = cls.methods
+        view.provide_automatic_options = cls.provide_automatic_options
+        return view
+
+
+class MethodViewType(type):
+    """Metaclass for :class:`MethodView` that determines what methods the view
+    defines.
+    """
+
+    def __init__(cls, name, bases, d):
+        super(MethodViewType, cls).__init__(name, bases, d)
+
+        if 'methods' not in d:
+            methods = set()
+
+            for key in http_method_funcs:
+                if hasattr(cls, key):
+                    methods.add(key.upper())
+
+            # If we have no method at all in there we don't want to add a
+            # method list. This is for instance the case for the base class
+            # or another subclass of a base method view that does not introduce
+            # new methods.
+            if methods:
+                cls.methods = methods
+
+
+class MethodView(with_metaclass(MethodViewType, View)):
+    """A class-based view that dispatches request methods to the corresponding
+    class methods. For example, if you implement a ``get`` method, it will be
+    used to handle ``GET`` requests. ::
+
+        class CounterAPI(MethodView):
+            def get(self):
+                return session.get('counter', 0)
+
+            def post(self):
+                session['counter'] = session.get('counter', 0) + 1
+                return 'OK'
+
+        app.add_url_rule('/counter', view_func=CounterAPI.as_view('counter'))
+    """
+
+    def dispatch_request(self, *args, **kwargs):
+        meth = getattr(self, request.method.lower(), None)
+
+        # If the request method is HEAD and we don't have a handler for it
+        # retry with GET.
+        if meth is None and request.method == 'HEAD':
+            meth = getattr(self, 'get', None)
+
+        assert meth is not None, 'Unimplemented method %r' % request.method
+        return meth(*args, **kwargs)
diff --git a/python/flask/wrappers.py b/python/flask/wrappers.py
new file mode 100644
index 0000000..12eff2c
--- /dev/null
+++ b/python/flask/wrappers.py
@@ -0,0 +1,216 @@
+# -*- coding: utf-8 -*-
+"""
+    flask.wrappers
+    ~~~~~~~~~~~~~~
+
+    Implements the WSGI wrappers (request and response).
+
+    :copyright: © 2010 by the Pallets team.
+    :license: BSD, see LICENSE for more details.
+"""
+
+from werkzeug.exceptions import BadRequest
+from werkzeug.wrappers import Request as RequestBase, Response as ResponseBase
+
+from flask import json
+from flask.globals import current_app
+
+
+class JSONMixin(object):
+    """Common mixin for both request and response objects to provide JSON
+    parsing capabilities.
+
+    .. versionadded:: 1.0
+    """
+
+    _cached_json = (Ellipsis, Ellipsis)
+
+    @property
+    def is_json(self):
+        """Check if the mimetype indicates JSON data, either
+        :mimetype:`application/json` or :mimetype:`application/*+json`.
+
+        .. versionadded:: 0.11
+        """
+        mt = self.mimetype
+        return (
+            mt == 'application/json'
+            or (mt.startswith('application/')) and mt.endswith('+json')
+        )
+
+    @property
+    def json(self):
+        """This will contain the parsed JSON data if the mimetype indicates
+        JSON (:mimetype:`application/json`, see :meth:`is_json`), otherwise it
+        will be ``None``.
+        """
+        return self.get_json()
+
+    def _get_data_for_json(self, cache):
+        return self.get_data(cache=cache)
+
+    def get_json(self, force=False, silent=False, cache=True):
+        """Parse and return the data as JSON. If the mimetype does not
+        indicate JSON (:mimetype:`application/json`, see
+        :meth:`is_json`), this returns ``None`` unless ``force`` is
+        true. If parsing fails, :meth:`on_json_loading_failed` is called
+        and its return value is used as the return value.
+
+        :param force: Ignore the mimetype and always try to parse JSON.
+        :param silent: Silence parsing errors and return ``None``
+            instead.
+        :param cache: Store the parsed JSON to return for subsequent
+            calls.
+        """
+        if cache and self._cached_json[silent] is not Ellipsis:
+            return self._cached_json[silent]
+
+        if not (force or self.is_json):
+            return None
+
+        data = self._get_data_for_json(cache=cache)
+
+        try:
+            rv = json.loads(data)
+        except ValueError as e:
+            if silent:
+                rv = None
+                if cache:
+                    normal_rv, _ = self._cached_json
+                    self._cached_json = (normal_rv, rv)
+            else:
+                rv = self.on_json_loading_failed(e)
+                if cache:
+                    _, silent_rv = self._cached_json
+                    self._cached_json = (rv, silent_rv)
+        else:
+            if cache:
+                self._cached_json = (rv, rv)
+
+        return rv
+
+    def on_json_loading_failed(self, e):
+        """Called if :meth:`get_json` parsing fails and isn't silenced. If
+        this method returns a value, it is used as the return value for
+        :meth:`get_json`. The default implementation raises a
+        :class:`BadRequest` exception.
+
+        .. versionchanged:: 0.10
+           Raise a :exc:`BadRequest` error instead of returning an error
+           message as JSON. If you want that behavior you can add it by
+           subclassing.
+
+        .. versionadded:: 0.8
+        """
+        if current_app is not None and current_app.debug:
+            raise BadRequest('Failed to decode JSON object: {0}'.format(e))
+
+        raise BadRequest()
+
+
+class Request(RequestBase, JSONMixin):
+    """The request object used by default in Flask.  Remembers the
+    matched endpoint and view arguments.
+
+    It is what ends up as :class:`~flask.request`.  If you want to replace
+    the request object used you can subclass this and set
+    :attr:`~flask.Flask.request_class` to your subclass.
+
+    The request object is a :class:`~werkzeug.wrappers.Request` subclass and
+    provides all of the attributes Werkzeug defines plus a few Flask
+    specific ones.
+    """
+
+    #: The internal URL rule that matched the request.  This can be
+    #: useful to inspect which methods are allowed for the URL from
+    #: a before/after handler (``request.url_rule.methods``) etc.
+    #: Though if the request's method was invalid for the URL rule,
+    #: the valid list is available in ``routing_exception.valid_methods``
+    #: instead (an attribute of the Werkzeug exception :exc:`~werkzeug.exceptions.MethodNotAllowed`)
+    #: because the request was never internally bound.
+    #:
+    #: .. versionadded:: 0.6
+    url_rule = None
+
+    #: A dict of view arguments that matched the request.  If an exception
+    #: happened when matching, this will be ``None``.
+    view_args = None
+
+    #: If matching the URL failed, this is the exception that will be
+    #: raised / was raised as part of the request handling.  This is
+    #: usually a :exc:`~werkzeug.exceptions.NotFound` exception or
+    #: something similar.
+    routing_exception = None
+
+    @property
+    def max_content_length(self):
+        """Read-only view of the ``MAX_CONTENT_LENGTH`` config key."""
+        if current_app:
+            return current_app.config['MAX_CONTENT_LENGTH']
+
+    @property
+    def endpoint(self):
+        """The endpoint that matched the request.  This in combination with
+        :attr:`view_args` can be used to reconstruct the same or a
+        modified URL.  If an exception happened when matching, this will
+        be ``None``.
+        """
+        if self.url_rule is not None:
+            return self.url_rule.endpoint
+
+    @property
+    def blueprint(self):
+        """The name of the current blueprint"""
+        if self.url_rule and '.' in self.url_rule.endpoint:
+            return self.url_rule.endpoint.rsplit('.', 1)[0]
+
+    def _load_form_data(self):
+        RequestBase._load_form_data(self)
+
+        # In debug mode we're replacing the files multidict with an ad-hoc
+        # subclass that raises a different error for key errors.
+        if (
+            current_app
+            and current_app.debug
+            and self.mimetype != 'multipart/form-data'
+            and not self.files
+        ):
+            from .debughelpers import attach_enctype_error_multidict
+            attach_enctype_error_multidict(self)
+
+
+class Response(ResponseBase, JSONMixin):
+    """The response object that is used by default in Flask.  Works like the
+    response object from Werkzeug but is set to have an HTML mimetype by
+    default.  Quite often you don't have to create this object yourself because
+    :meth:`~flask.Flask.make_response` will take care of that for you.
+
+    If you want to replace the response object used you can subclass this and
+    set :attr:`~flask.Flask.response_class` to your subclass.
+
+    .. versionchanged:: 1.0
+        JSON support is added to the response, like the request. This is useful
+        when testing to get the test client response data as JSON.
+
+    .. versionchanged:: 1.0
+
+        Added :attr:`max_cookie_size`.
+    """
+
+    default_mimetype = 'text/html'
+
+    def _get_data_for_json(self, cache):
+        return self.get_data()
+
+    @property
+    def max_cookie_size(self):
+        """Read-only view of the :data:`MAX_COOKIE_SIZE` config key.
+
+        See :attr:`~werkzeug.wrappers.BaseResponse.max_cookie_size` in
+        Werkzeug's docs.
+        """
+        if current_app:
+            return current_app.config['MAX_COOKIE_SIZE']
+
+        # return Werkzeug's default when not in an app context
+        return super(Response, self).max_cookie_size