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)
| 58 | |
| 59 | |
| 60 | def find_referenced_templates(ast): |
| 61 | """Finds all the referenced templates from the AST. This will return an |
| 62 | iterator over all the hardcoded template extensions, inclusions and |
| 63 | imports. If dynamic inheritance or inclusion is used, `None` will be |
| 64 | yielded. |
| 65 | |
| 66 | >>> from jinja2 import Environment, meta |
| 67 | >>> env = Environment() |
| 68 | >>> ast = env.parse('{% extends "layout.html" %}{% include helper %}') |
| 69 | >>> list(meta.find_referenced_templates(ast)) |
| 70 | ['layout.html', None] |
| 71 | |
| 72 | This function is useful for dependency tracking. For example if you want |
| 73 | to rebuild parts of the website after a layout template has changed. |
| 74 | """ |
| 75 | for node in ast.find_all((nodes.Extends, nodes.FromImport, nodes.Import, |
| 76 | nodes.Include)): |
| 77 | if not isinstance(node.template, nodes.Const): |
| 78 | # a tuple with some non consts in there |
| 79 | if isinstance(node.template, (nodes.Tuple, nodes.List)): |
| 80 | for template_name in node.template.items: |
| 81 | # something const, only yield the strings and ignore |
| 82 | # non-string consts that really just make no sense |
| 83 | if isinstance(template_name, nodes.Const): |
| 84 | if isinstance(template_name.value, string_types): |
| 85 | yield template_name.value |
| 86 | # something dynamic in there |
| 87 | else: |
| 88 | yield None |
| 89 | # something dynamic we don't know about here |
| 90 | else: |
| 91 | yield None |
| 92 | continue |
| 93 | # constant is a basestring, direct template name |
| 94 | if isinstance(node.template.value, string_types): |
| 95 | yield node.template.value |
| 96 | # a tuple or list (latter *should* not happen) made of consts, |
| 97 | # yield the consts that are strings. We could warn here for |
| 98 | # non string values |
| 99 | elif isinstance(node, nodes.Include) and \ |
| 100 | isinstance(node.template.value, (tuple, list)): |
| 101 | for template_name in node.template.value: |
| 102 | if isinstance(template_name, string_types): |
| 103 | yield template_name |
| 104 | # something else we don't care about, we could warn here |
| 105 | else: |
| 106 | yield None |