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: nodes.Template)
| 59 | |
| 60 | |
| 61 | def find_referenced_templates(ast: nodes.Template) -> t.Iterator[t.Optional[str]]: |
| 62 | """Finds all the referenced templates from the AST. This will return an |
| 63 | iterator over all the hardcoded template extensions, inclusions and |
| 64 | imports. If dynamic inheritance or inclusion is used, `None` will be |
| 65 | yielded. |
| 66 | |
| 67 | >>> from jinja2 import Environment, meta |
| 68 | >>> env = Environment() |
| 69 | >>> ast = env.parse('{% extends "layout.html" %}{% include helper %}') |
| 70 | >>> list(meta.find_referenced_templates(ast)) |
| 71 | ['layout.html', None] |
| 72 | |
| 73 | This function is useful for dependency tracking. For example if you want |
| 74 | to rebuild parts of the website after a layout template has changed. |
| 75 | """ |
| 76 | template_name: t.Any |
| 77 | |
| 78 | for node in ast.find_all(_ref_types): |
| 79 | template: nodes.Expr = node.template # type: ignore |
| 80 | |
| 81 | if not isinstance(template, nodes.Const): |
| 82 | # a tuple with some non consts in there |
| 83 | if isinstance(template, (nodes.Tuple, nodes.List)): |
| 84 | for template_name in template.items: |
| 85 | # something const, only yield the strings and ignore |
| 86 | # non-string consts that really just make no sense |
| 87 | if isinstance(template_name, nodes.Const): |
| 88 | if isinstance(template_name.value, str): |
| 89 | yield template_name.value |
| 90 | # something dynamic in there |
| 91 | else: |
| 92 | yield None |
| 93 | # something dynamic we don't know about here |
| 94 | else: |
| 95 | yield None |
| 96 | continue |
| 97 | # constant is a basestring, direct template name |
| 98 | if isinstance(template.value, str): |
| 99 | yield template.value |
| 100 | # a tuple or list (latter *should* not happen) made of consts, |
| 101 | # yield the consts that are strings. We could warn here for |
| 102 | # non string values |
| 103 | elif isinstance(node, nodes.Include) and isinstance( |
| 104 | template.value, (tuple, list) |
| 105 | ): |
| 106 | for template_name in template.value: |
| 107 | if isinstance(template_name, str): |
| 108 | yield template_name |
| 109 | # something else we don't care about, we could warn here |
| 110 | else: |
| 111 | yield None |