diff options
Diffstat (limited to 'python/jinja2/runtime.py')
| -rw-r--r-- | python/jinja2/runtime.py | 813 |
1 files changed, 0 insertions, 813 deletions
diff --git a/python/jinja2/runtime.py b/python/jinja2/runtime.py deleted file mode 100644 index f9d7a68..0000000 --- a/python/jinja2/runtime.py +++ /dev/null @@ -1,813 +0,0 @@ -# -*- coding: utf-8 -*- -""" - jinja2.runtime - ~~~~~~~~~~~~~~ - - Runtime helpers. - - :copyright: (c) 2017 by the Jinja Team. - :license: BSD. -""" -import sys - -from itertools import chain -from types import MethodType - -from jinja2.nodes import EvalContext, _context_function_types -from jinja2.utils import Markup, soft_unicode, escape, missing, concat, \ - internalcode, object_type_repr, evalcontextfunction, Namespace -from jinja2.exceptions import UndefinedError, TemplateRuntimeError, \ - TemplateNotFound -from jinja2._compat import imap, text_type, iteritems, \ - implements_iterator, implements_to_string, string_types, PY2, \ - with_metaclass - - -# these variables are exported to the template runtime -__all__ = ['LoopContext', 'TemplateReference', 'Macro', 'Markup', - 'TemplateRuntimeError', 'missing', 'concat', 'escape', - 'markup_join', 'unicode_join', 'to_string', 'identity', - 'TemplateNotFound', 'Namespace'] - -#: the name of the function that is used to convert something into -#: a string. We can just use the text type here. -to_string = text_type - -#: the identity function. Useful for certain things in the environment -identity = lambda x: x - -_first_iteration = object() -_last_iteration = object() - - -def markup_join(seq): - """Concatenation that escapes if necessary and converts to unicode.""" - buf = [] - iterator = imap(soft_unicode, seq) - for arg in iterator: - buf.append(arg) - if hasattr(arg, '__html__'): - return Markup(u'').join(chain(buf, iterator)) - return concat(buf) - - -def unicode_join(seq): - """Simple args to unicode conversion and concatenation.""" - return concat(imap(text_type, seq)) - - -def new_context(environment, template_name, blocks, vars=None, - shared=None, globals=None, locals=None): - """Internal helper to for context creation.""" - if vars is None: - vars = {} - if shared: - parent = vars - else: - parent = dict(globals or (), **vars) - if locals: - # if the parent is shared a copy should be created because - # we don't want to modify the dict passed - if shared: - parent = dict(parent) - for key, value in iteritems(locals): - if value is not missing: - parent[key] = value - return environment.context_class(environment, parent, template_name, - blocks) - - -class TemplateReference(object): - """The `self` in templates.""" - - def __init__(self, context): - self.__context = context - - def __getitem__(self, name): - blocks = self.__context.blocks[name] - return BlockReference(name, self.__context, blocks, 0) - - def __repr__(self): - return '<%s %r>' % ( - self.__class__.__name__, - self.__context.name - ) - - -def _get_func(x): - return getattr(x, '__func__', x) - - -class ContextMeta(type): - - def __new__(cls, name, bases, d): - rv = type.__new__(cls, name, bases, d) - if bases == (): - return rv - - resolve = _get_func(rv.resolve) - default_resolve = _get_func(Context.resolve) - resolve_or_missing = _get_func(rv.resolve_or_missing) - default_resolve_or_missing = _get_func(Context.resolve_or_missing) - - # If we have a changed resolve but no changed default or missing - # resolve we invert the call logic. - if resolve is not default_resolve and \ - resolve_or_missing is default_resolve_or_missing: - rv._legacy_resolve_mode = True - elif resolve is default_resolve and \ - resolve_or_missing is default_resolve_or_missing: - rv._fast_resolve_mode = True - - return rv - - -def resolve_or_missing(context, key, missing=missing): - if key in context.vars: - return context.vars[key] - if key in context.parent: - return context.parent[key] - return missing - - -class Context(with_metaclass(ContextMeta)): - """The template context holds the variables of a template. It stores the - values passed to the template and also the names the template exports. - Creating instances is neither supported nor useful as it's created - automatically at various stages of the template evaluation and should not - be created by hand. - - The context is immutable. Modifications on :attr:`parent` **must not** - happen and modifications on :attr:`vars` are allowed from generated - template code only. Template filters and global functions marked as - :func:`contextfunction`\\s get the active context passed as first argument - and are allowed to access the context read-only. - - The template context supports read only dict operations (`get`, - `keys`, `values`, `items`, `iterkeys`, `itervalues`, `iteritems`, - `__getitem__`, `__contains__`). Additionally there is a :meth:`resolve` - method that doesn't fail with a `KeyError` but returns an - :class:`Undefined` object for missing variables. - """ - # XXX: we want to eventually make this be a deprecation warning and - # remove it. - _legacy_resolve_mode = False - _fast_resolve_mode = False - - def __init__(self, environment, parent, name, blocks): - self.parent = parent - self.vars = {} - self.environment = environment - self.eval_ctx = EvalContext(self.environment, name) - self.exported_vars = set() - self.name = name - - # create the initial mapping of blocks. Whenever template inheritance - # takes place the runtime will update this mapping with the new blocks - # from the template. - self.blocks = dict((k, [v]) for k, v in iteritems(blocks)) - - # In case we detect the fast resolve mode we can set up an alias - # here that bypasses the legacy code logic. - if self._fast_resolve_mode: - self.resolve_or_missing = MethodType(resolve_or_missing, self) - - def super(self, name, current): - """Render a parent block.""" - try: - blocks = self.blocks[name] - index = blocks.index(current) + 1 - blocks[index] - except LookupError: - return self.environment.undefined('there is no parent block ' - 'called %r.' % name, - name='super') - return BlockReference(name, self, blocks, index) - - def get(self, key, default=None): - """Returns an item from the template context, if it doesn't exist - `default` is returned. - """ - try: - return self[key] - except KeyError: - return default - - def resolve(self, key): - """Looks up a variable like `__getitem__` or `get` but returns an - :class:`Undefined` object with the name of the name looked up. - """ - if self._legacy_resolve_mode: - rv = resolve_or_missing(self, key) - else: - rv = self.resolve_or_missing(key) - if rv is missing: - return self.environment.undefined(name=key) - return rv - - def resolve_or_missing(self, key): - """Resolves a variable like :meth:`resolve` but returns the - special `missing` value if it cannot be found. - """ - if self._legacy_resolve_mode: - rv = self.resolve(key) - if isinstance(rv, Undefined): - rv = missing - return rv - return resolve_or_missing(self, key) - - def get_exported(self): - """Get a new dict with the exported variables.""" - return dict((k, self.vars[k]) for k in self.exported_vars) - - def get_all(self): - """Return the complete context as dict including the exported - variables. For optimizations reasons this might not return an - actual copy so be careful with using it. - """ - if not self.vars: - return self.parent - if not self.parent: - return self.vars - return dict(self.parent, **self.vars) - - @internalcode - def call(__self, __obj, *args, **kwargs): - """Call the callable with the arguments and keyword arguments - provided but inject the active context or environment as first - argument if the callable is a :func:`contextfunction` or - :func:`environmentfunction`. - """ - if __debug__: - __traceback_hide__ = True # noqa - - # Allow callable classes to take a context - if hasattr(__obj, '__call__'): - fn = __obj.__call__ - for fn_type in ('contextfunction', - 'evalcontextfunction', - 'environmentfunction'): - if hasattr(fn, fn_type): - __obj = fn - break - - if isinstance(__obj, _context_function_types): - if getattr(__obj, 'contextfunction', 0): - args = (__self,) + args - elif getattr(__obj, 'evalcontextfunction', 0): - args = (__self.eval_ctx,) + args - elif getattr(__obj, 'environmentfunction', 0): - args = (__self.environment,) + args - try: - return __obj(*args, **kwargs) - except StopIteration: - return __self.environment.undefined('value was undefined because ' - 'a callable raised a ' - 'StopIteration exception') - - def derived(self, locals=None): - """Internal helper function to create a derived context. This is - used in situations where the system needs a new context in the same - template that is independent. - """ - context = new_context(self.environment, self.name, {}, - self.get_all(), True, None, locals) - context.eval_ctx = self.eval_ctx - context.blocks.update((k, list(v)) for k, v in iteritems(self.blocks)) - return context - - def _all(meth): - proxy = lambda self: getattr(self.get_all(), meth)() - proxy.__doc__ = getattr(dict, meth).__doc__ - proxy.__name__ = meth - return proxy - - keys = _all('keys') - values = _all('values') - items = _all('items') - - # not available on python 3 - if PY2: - iterkeys = _all('iterkeys') - itervalues = _all('itervalues') - iteritems = _all('iteritems') - del _all - - def __contains__(self, name): - return name in self.vars or name in self.parent - - def __getitem__(self, key): - """Lookup a variable or raise `KeyError` if the variable is - undefined. - """ - item = self.resolve_or_missing(key) - if item is missing: - raise KeyError(key) - return item - - def __repr__(self): - return '<%s %s of %r>' % ( - self.__class__.__name__, - repr(self.get_all()), - self.name - ) - - -# register the context as mapping if possible -try: - from collections import Mapping - Mapping.register(Context) -except ImportError: - pass - - -class BlockReference(object): - """One block on a template reference.""" - - def __init__(self, name, context, stack, depth): - self.name = name - self._context = context - self._stack = stack - self._depth = depth - - @property - def super(self): - """Super the block.""" - if self._depth + 1 >= len(self._stack): - return self._context.environment. \ - undefined('there is no parent block called %r.' % - self.name, name='super') - return BlockReference(self.name, self._context, self._stack, - self._depth + 1) - - @internalcode - def __call__(self): - rv = concat(self._stack[self._depth](self._context)) - if self._context.eval_ctx.autoescape: - rv = Markup(rv) - return rv - - -class LoopContextBase(object): - """A loop context for dynamic iteration.""" - - _before = _first_iteration - _current = _first_iteration - _after = _last_iteration - _length = None - - def __init__(self, undefined, recurse=None, depth0=0): - self._undefined = undefined - self._recurse = recurse - self.index0 = -1 - self.depth0 = depth0 - self._last_checked_value = missing - - def cycle(self, *args): - """Cycles among the arguments with the current loop index.""" - if not args: - raise TypeError('no items for cycling given') - return args[self.index0 % len(args)] - - def changed(self, *value): - """Checks whether the value has changed since the last call.""" - if self._last_checked_value != value: - self._last_checked_value = value - return True - return False - - first = property(lambda x: x.index0 == 0) - last = property(lambda x: x._after is _last_iteration) - index = property(lambda x: x.index0 + 1) - revindex = property(lambda x: x.length - x.index0) - revindex0 = property(lambda x: x.length - x.index) - depth = property(lambda x: x.depth0 + 1) - - @property - def previtem(self): - if self._before is _first_iteration: - return self._undefined('there is no previous item') - return self._before - - @property - def nextitem(self): - if self._after is _last_iteration: - return self._undefined('there is no next item') - return self._after - - def __len__(self): - return self.length - - @internalcode - def loop(self, iterable): - if self._recurse is None: - raise TypeError('Tried to call non recursive loop. Maybe you ' - "forgot the 'recursive' modifier.") - return self._recurse(iterable, self._recurse, self.depth0 + 1) - - # a nifty trick to enhance the error message if someone tried to call - # the the loop without or with too many arguments. - __call__ = loop - del loop - - def __repr__(self): - return '<%s %r/%r>' % ( - self.__class__.__name__, - self.index, - self.length - ) - - -class LoopContext(LoopContextBase): - - def __init__(self, iterable, undefined, recurse=None, depth0=0): - LoopContextBase.__init__(self, undefined, recurse, depth0) - self._iterator = iter(iterable) - - # try to get the length of the iterable early. This must be done - # here because there are some broken iterators around where there - # __len__ is the number of iterations left (i'm looking at your - # listreverseiterator!). - try: - self._length = len(iterable) - except (TypeError, AttributeError): - self._length = None - self._after = self._safe_next() - - @property - def length(self): - if self._length is None: - # if was not possible to get the length of the iterator when - # the loop context was created (ie: iterating over a generator) - # we have to convert the iterable into a sequence and use the - # length of that + the number of iterations so far. - iterable = tuple(self._iterator) - self._iterator = iter(iterable) - iterations_done = self.index0 + 2 - self._length = len(iterable) + iterations_done - return self._length - - def __iter__(self): - return LoopContextIterator(self) - - def _safe_next(self): - try: - return next(self._iterator) - except StopIteration: - return _last_iteration - - -@implements_iterator -class LoopContextIterator(object): - """The iterator for a loop context.""" - __slots__ = ('context',) - - def __init__(self, context): - self.context = context - - def __iter__(self): - return self - - def __next__(self): - ctx = self.context - ctx.index0 += 1 - if ctx._after is _last_iteration: - raise StopIteration() - ctx._before = ctx._current - ctx._current = ctx._after - ctx._after = ctx._safe_next() - return ctx._current, ctx - - -class Macro(object): - """Wraps a macro function.""" - - def __init__(self, environment, func, name, arguments, - catch_kwargs, catch_varargs, caller, - default_autoescape=None): - self._environment = environment - self._func = func - self._argument_count = len(arguments) - self.name = name - self.arguments = arguments - self.catch_kwargs = catch_kwargs - self.catch_varargs = catch_varargs - self.caller = caller - self.explicit_caller = 'caller' in arguments - if default_autoescape is None: - default_autoescape = environment.autoescape - self._default_autoescape = default_autoescape - - @internalcode - @evalcontextfunction - def __call__(self, *args, **kwargs): - # This requires a bit of explanation, In the past we used to - # decide largely based on compile-time information if a macro is - # safe or unsafe. While there was a volatile mode it was largely - # unused for deciding on escaping. This turns out to be - # problemtic for macros because if a macro is safe or not not so - # much depends on the escape mode when it was defined but when it - # was used. - # - # Because however we export macros from the module system and - # there are historic callers that do not pass an eval context (and - # will continue to not pass one), we need to perform an instance - # check here. - # - # This is considered safe because an eval context is not a valid - # argument to callables otherwise anwyays. Worst case here is - # that if no eval context is passed we fall back to the compile - # time autoescape flag. - if args and isinstance(args[0], EvalContext): - autoescape = args[0].autoescape - args = args[1:] - else: - autoescape = self._default_autoescape - - # try to consume the positional arguments - arguments = list(args[:self._argument_count]) - off = len(arguments) - - # For information why this is necessary refer to the handling - # of caller in the `macro_body` handler in the compiler. - found_caller = False - - # if the number of arguments consumed is not the number of - # arguments expected we start filling in keyword arguments - # and defaults. - if off != self._argument_count: - for idx, name in enumerate(self.arguments[len(arguments):]): - try: - value = kwargs.pop(name) - except KeyError: - value = missing - if name == 'caller': - found_caller = True - arguments.append(value) - else: - found_caller = self.explicit_caller - - # it's important that the order of these arguments does not change - # if not also changed in the compiler's `function_scoping` method. - # the order is caller, keyword arguments, positional arguments! - if self.caller and not found_caller: - caller = kwargs.pop('caller', None) - if caller is None: - caller = self._environment.undefined('No caller defined', - name='caller') - arguments.append(caller) - - if self.catch_kwargs: - arguments.append(kwargs) - elif kwargs: - if 'caller' in kwargs: - raise TypeError('macro %r was invoked with two values for ' - 'the special caller argument. This is ' - 'most likely a bug.' % self.name) - raise TypeError('macro %r takes no keyword argument %r' % - (self.name, next(iter(kwargs)))) - if self.catch_varargs: - arguments.append(args[self._argument_count:]) - elif len(args) > self._argument_count: - raise TypeError('macro %r takes not more than %d argument(s)' % - (self.name, len(self.arguments))) - - return self._invoke(arguments, autoescape) - - def _invoke(self, arguments, autoescape): - """This method is being swapped out by the async implementation.""" - rv = self._func(*arguments) - if autoescape: - rv = Markup(rv) - return rv - - def __repr__(self): - return '<%s %s>' % ( - self.__class__.__name__, - self.name is None and 'anonymous' or repr(self.name) - ) - - -@implements_to_string -class Undefined(object): - """The default undefined type. This undefined type can be printed and - iterated over, but every other access will raise an :exc:`jinja2.exceptions.UndefinedError`: - - >>> foo = Undefined(name='foo') - >>> str(foo) - '' - >>> not foo - True - >>> foo + 42 - Traceback (most recent call last): - ... - jinja2.exceptions.UndefinedError: 'foo' is undefined - """ - __slots__ = ('_undefined_hint', '_undefined_obj', '_undefined_name', - '_undefined_exception') - - def __init__(self, hint=None, obj=missing, name=None, exc=UndefinedError): - self._undefined_hint = hint - self._undefined_obj = obj - self._undefined_name = name - self._undefined_exception = exc - - @internalcode - def _fail_with_undefined_error(self, *args, **kwargs): - """Regular callback function for undefined objects that raises an - `jinja2.exceptions.UndefinedError` on call. - """ - if self._undefined_hint is None: - if self._undefined_obj is missing: - hint = '%r is undefined' % self._undefined_name - elif not isinstance(self._undefined_name, string_types): - hint = '%s has no element %r' % ( - object_type_repr(self._undefined_obj), - self._undefined_name - ) - else: - hint = '%r has no attribute %r' % ( - object_type_repr(self._undefined_obj), - self._undefined_name - ) - else: - hint = self._undefined_hint - raise self._undefined_exception(hint) - - @internalcode - def __getattr__(self, name): - if name[:2] == '__': - raise AttributeError(name) - return self._fail_with_undefined_error() - - __add__ = __radd__ = __mul__ = __rmul__ = __div__ = __rdiv__ = \ - __truediv__ = __rtruediv__ = __floordiv__ = __rfloordiv__ = \ - __mod__ = __rmod__ = __pos__ = __neg__ = __call__ = \ - __getitem__ = __lt__ = __le__ = __gt__ = __ge__ = __int__ = \ - __float__ = __complex__ = __pow__ = __rpow__ = __sub__ = \ - __rsub__ = _fail_with_undefined_error - - def __eq__(self, other): - return type(self) is type(other) - - def __ne__(self, other): - return not self.__eq__(other) - - def __hash__(self): - return id(type(self)) - - def __str__(self): - return u'' - - def __len__(self): - return 0 - - def __iter__(self): - if 0: - yield None - - def __nonzero__(self): - return False - __bool__ = __nonzero__ - - def __repr__(self): - return 'Undefined' - - -def make_logging_undefined(logger=None, base=None): - """Given a logger object this returns a new undefined class that will - log certain failures. It will log iterations and printing. If no - logger is given a default logger is created. - - Example:: - - logger = logging.getLogger(__name__) - LoggingUndefined = make_logging_undefined( - logger=logger, - base=Undefined - ) - - .. versionadded:: 2.8 - - :param logger: the logger to use. If not provided, a default logger - is created. - :param base: the base class to add logging functionality to. This - defaults to :class:`Undefined`. - """ - if logger is None: - import logging - logger = logging.getLogger(__name__) - logger.addHandler(logging.StreamHandler(sys.stderr)) - if base is None: - base = Undefined - - def _log_message(undef): - if undef._undefined_hint is None: - if undef._undefined_obj is missing: - hint = '%s is undefined' % undef._undefined_name - elif not isinstance(undef._undefined_name, string_types): - hint = '%s has no element %s' % ( - object_type_repr(undef._undefined_obj), - undef._undefined_name) - else: - hint = '%s has no attribute %s' % ( - object_type_repr(undef._undefined_obj), - undef._undefined_name) - else: - hint = undef._undefined_hint - logger.warning('Template variable warning: %s', hint) - - class LoggingUndefined(base): - - def _fail_with_undefined_error(self, *args, **kwargs): - try: - return base._fail_with_undefined_error(self, *args, **kwargs) - except self._undefined_exception as e: - logger.error('Template variable error: %s', str(e)) - raise e - - def __str__(self): - rv = base.__str__(self) - _log_message(self) - return rv - - def __iter__(self): - rv = base.__iter__(self) - _log_message(self) - return rv - - if PY2: - def __nonzero__(self): - rv = base.__nonzero__(self) - _log_message(self) - return rv - - def __unicode__(self): - rv = base.__unicode__(self) - _log_message(self) - return rv - else: - def __bool__(self): - rv = base.__bool__(self) - _log_message(self) - return rv - - return LoggingUndefined - - -@implements_to_string -class DebugUndefined(Undefined): - """An undefined that returns the debug info when printed. - - >>> foo = DebugUndefined(name='foo') - >>> str(foo) - '{{ foo }}' - >>> not foo - True - >>> foo + 42 - Traceback (most recent call last): - ... - jinja2.exceptions.UndefinedError: 'foo' is undefined - """ - __slots__ = () - - def __str__(self): - if self._undefined_hint is None: - if self._undefined_obj is missing: - return u'{{ %s }}' % self._undefined_name - return '{{ no such element: %s[%r] }}' % ( - object_type_repr(self._undefined_obj), - self._undefined_name - ) - return u'{{ undefined value printed: %s }}' % self._undefined_hint - - -@implements_to_string -class StrictUndefined(Undefined): - """An undefined that barks on print and iteration as well as boolean - tests and all kinds of comparisons. In other words: you can do nothing - with it except checking if it's defined using the `defined` test. - - >>> foo = StrictUndefined(name='foo') - >>> str(foo) - Traceback (most recent call last): - ... - jinja2.exceptions.UndefinedError: 'foo' is undefined - >>> not foo - Traceback (most recent call last): - ... - jinja2.exceptions.UndefinedError: 'foo' is undefined - >>> foo + 42 - Traceback (most recent call last): - ... - jinja2.exceptions.UndefinedError: 'foo' is undefined - """ - __slots__ = () - __iter__ = __str__ = __len__ = __nonzero__ = __eq__ = \ - __ne__ = __bool__ = __hash__ = \ - Undefined._fail_with_undefined_error - - -# remove remaining slots attributes, after the metaclass did the magic they -# are unneeded and irritating as they contain wrong data for the subclasses. -del Undefined.__slots__, DebugUndefined.__slots__, StrictUndefined.__slots__ |