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Diffstat (limited to 'python/jinja2/meta.py')
-rw-r--r-- | python/jinja2/meta.py | 106 |
1 files changed, 0 insertions, 106 deletions
diff --git a/python/jinja2/meta.py b/python/jinja2/meta.py deleted file mode 100644 index 7421914..0000000 --- a/python/jinja2/meta.py +++ /dev/null @@ -1,106 +0,0 @@ -# -*- coding: utf-8 -*- -""" - jinja2.meta - ~~~~~~~~~~~ - - This module implements various functions that exposes information about - templates that might be interesting for various kinds of applications. - - :copyright: (c) 2017 by the Jinja Team, see AUTHORS for more details. - :license: BSD, see LICENSE for more details. -""" -from jinja2 import nodes -from jinja2.compiler import CodeGenerator -from jinja2._compat import string_types, iteritems - - -class TrackingCodeGenerator(CodeGenerator): - """We abuse the code generator for introspection.""" - - def __init__(self, environment): - CodeGenerator.__init__(self, environment, '<introspection>', - '<introspection>') - self.undeclared_identifiers = set() - - def write(self, x): - """Don't write.""" - - def enter_frame(self, frame): - """Remember all undeclared identifiers.""" - CodeGenerator.enter_frame(self, frame) - for _, (action, param) in iteritems(frame.symbols.loads): - if action == 'resolve': - self.undeclared_identifiers.add(param) - - -def find_undeclared_variables(ast): - """Returns a set of all variables in the AST that will be looked up from - the context at runtime. Because at compile time it's not known which - variables will be used depending on the path the execution takes at - runtime, all variables are returned. - - >>> from jinja2 import Environment, meta - >>> env = Environment() - >>> ast = env.parse('{% set foo = 42 %}{{ bar + foo }}') - >>> meta.find_undeclared_variables(ast) == set(['bar']) - True - - .. admonition:: Implementation - - Internally the code generator is used for finding undeclared variables. - This is good to know because the code generator might raise a - :exc:`TemplateAssertionError` during compilation and as a matter of - fact this function can currently raise that exception as well. - """ - codegen = TrackingCodeGenerator(ast.environment) - codegen.visit(ast) - return codegen.undeclared_identifiers - - -def find_referenced_templates(ast): - """Finds all the referenced templates from the AST. This will return an - iterator over all the hardcoded template extensions, inclusions and - imports. If dynamic inheritance or inclusion is used, `None` will be - yielded. - - >>> from jinja2 import Environment, meta - >>> env = Environment() - >>> ast = env.parse('{% extends "layout.html" %}{% include helper %}') - >>> list(meta.find_referenced_templates(ast)) - ['layout.html', None] - - This function is useful for dependency tracking. For example if you want - to rebuild parts of the website after a layout template has changed. - """ - for node in ast.find_all((nodes.Extends, nodes.FromImport, nodes.Import, - nodes.Include)): - if not isinstance(node.template, nodes.Const): - # a tuple with some non consts in there - if isinstance(node.template, (nodes.Tuple, nodes.List)): - for template_name in node.template.items: - # something const, only yield the strings and ignore - # non-string consts that really just make no sense - if isinstance(template_name, nodes.Const): - if isinstance(template_name.value, string_types): - yield template_name.value - # something dynamic in there - else: - yield None - # something dynamic we don't know about here - else: - yield None - continue - # constant is a basestring, direct template name - if isinstance(node.template.value, string_types): - yield node.template.value - # a tuple or list (latter *should* not happen) made of consts, - # yield the consts that are strings. We could warn here for - # non string values - elif isinstance(node, nodes.Include) and \ - isinstance(node.template.value, (tuple, list)): - for template_name in node.template.value: - if isinstance(template_name, string_types): - yield template_name - # something else we don't care about, we could warn here - else: - yield None |