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+"""Extension API for adding custom tags and behavior."""
+import pprint
+import re
+import typing as t
+
+from markupsafe import Markup
+
+from . import defaults
+from . import nodes
+from .environment import Environment
+from .exceptions import TemplateAssertionError
+from .exceptions import TemplateSyntaxError
+from .runtime import concat # type: ignore
+from .runtime import Context
+from .runtime import Undefined
+from .utils import import_string
+from .utils import pass_context
+
+if t.TYPE_CHECKING:
+ import typing_extensions as te
+ from .lexer import Token
+ from .lexer import TokenStream
+ from .parser import Parser
+
+ class _TranslationsBasic(te.Protocol):
+ def gettext(self, message: str) -> str:
+ ...
+
+ def ngettext(self, singular: str, plural: str, n: int) -> str:
+ pass
+
+ class _TranslationsContext(_TranslationsBasic):
+ def pgettext(self, context: str, message: str) -> str:
+ ...
+
+ def npgettext(self, context: str, singular: str, plural: str, n: int) -> str:
+ ...
+
+ _SupportedTranslations = t.Union[_TranslationsBasic, _TranslationsContext]
+
+
+# I18N functions available in Jinja templates. If the I18N library
+# provides ugettext, it will be assigned to gettext.
+GETTEXT_FUNCTIONS: t.Tuple[str, ...] = (
+ "_",
+ "gettext",
+ "ngettext",
+ "pgettext",
+ "npgettext",
+)
+_ws_re = re.compile(r"\s*\n\s*")
+
+
+class Extension:
+ """Extensions can be used to add extra functionality to the Jinja template
+ system at the parser level. Custom extensions are bound to an environment
+ but may not store environment specific data on `self`. The reason for
+ this is that an extension can be bound to another environment (for
+ overlays) by creating a copy and reassigning the `environment` attribute.
+
+ As extensions are created by the environment they cannot accept any
+ arguments for configuration. One may want to work around that by using
+ a factory function, but that is not possible as extensions are identified
+ by their import name. The correct way to configure the extension is
+ storing the configuration values on the environment. Because this way the
+ environment ends up acting as central configuration storage the
+ attributes may clash which is why extensions have to ensure that the names
+ they choose for configuration are not too generic. ``prefix`` for example
+ is a terrible name, ``fragment_cache_prefix`` on the other hand is a good
+ name as includes the name of the extension (fragment cache).
+ """
+
+ identifier: t.ClassVar[str]
+
+ def __init_subclass__(cls) -> None:
+ cls.identifier = f"{cls.__module__}.{cls.__name__}"
+
+ #: if this extension parses this is the list of tags it's listening to.
+ tags: t.Set[str] = set()
+
+ #: the priority of that extension. This is especially useful for
+ #: extensions that preprocess values. A lower value means higher
+ #: priority.
+ #:
+ #: .. versionadded:: 2.4
+ priority = 100
+
+ def __init__(self, environment: Environment) -> None:
+ self.environment = environment
+
+ def bind(self, environment: Environment) -> "Extension":
+ """Create a copy of this extension bound to another environment."""
+ rv = object.__new__(self.__class__)
+ rv.__dict__.update(self.__dict__)
+ rv.environment = environment
+ return rv
+
+ def preprocess(
+ self, source: str, name: t.Optional[str], filename: t.Optional[str] = None
+ ) -> str:
+ """This method is called before the actual lexing and can be used to
+ preprocess the source. The `filename` is optional. The return value
+ must be the preprocessed source.
+ """
+ return source
+
+ def filter_stream(
+ self, stream: "TokenStream"
+ ) -> t.Union["TokenStream", t.Iterable["Token"]]:
+ """It's passed a :class:`~jinja2.lexer.TokenStream` that can be used
+ to filter tokens returned. This method has to return an iterable of
+ :class:`~jinja2.lexer.Token`\\s, but it doesn't have to return a
+ :class:`~jinja2.lexer.TokenStream`.
+ """
+ return stream
+
+ def parse(self, parser: "Parser") -> t.Union[nodes.Node, t.List[nodes.Node]]:
+ """If any of the :attr:`tags` matched this method is called with the
+ parser as first argument. The token the parser stream is pointing at
+ is the name token that matched. This method has to return one or a
+ list of multiple nodes.
+ """
+ raise NotImplementedError()
+
+ def attr(
+ self, name: str, lineno: t.Optional[int] = None
+ ) -> nodes.ExtensionAttribute:
+ """Return an attribute node for the current extension. This is useful
+ to pass constants on extensions to generated template code.
+
+ ::
+
+ self.attr('_my_attribute', lineno=lineno)
+ """
+ return nodes.ExtensionAttribute(self.identifier, name, lineno=lineno)
+
+ def call_method(
+ self,
+ name: str,
+ args: t.Optional[t.List[nodes.Expr]] = None,
+ kwargs: t.Optional[t.List[nodes.Keyword]] = None,
+ dyn_args: t.Optional[nodes.Expr] = None,
+ dyn_kwargs: t.Optional[nodes.Expr] = None,
+ lineno: t.Optional[int] = None,
+ ) -> nodes.Call:
+ """Call a method of the extension. This is a shortcut for
+ :meth:`attr` + :class:`jinja2.nodes.Call`.
+ """
+ if args is None:
+ args = []
+ if kwargs is None:
+ kwargs = []
+ return nodes.Call(
+ self.attr(name, lineno=lineno),
+ args,
+ kwargs,
+ dyn_args,
+ dyn_kwargs,
+ lineno=lineno,
+ )
+
+
+@pass_context
+def _gettext_alias(
+ __context: Context, *args: t.Any, **kwargs: t.Any
+) -> t.Union[t.Any, Undefined]:
+ return __context.call(__context.resolve("gettext"), *args, **kwargs)
+
+
+def _make_new_gettext(func: t.Callable[[str], str]) -> t.Callable[..., str]:
+ @pass_context
+ def gettext(__context: Context, __string: str, **variables: t.Any) -> str:
+ rv = __context.call(func, __string)
+ if __context.eval_ctx.autoescape:
+ rv = Markup(rv)
+ # Always treat as a format string, even if there are no
+ # variables. This makes translation strings more consistent
+ # and predictable. This requires escaping
+ return rv % variables # type: ignore
+
+ return gettext
+
+
+def _make_new_ngettext(func: t.Callable[[str, str, int], str]) -> t.Callable[..., str]:
+ @pass_context
+ def ngettext(
+ __context: Context,
+ __singular: str,
+ __plural: str,
+ __num: int,
+ **variables: t.Any,
+ ) -> str:
+ variables.setdefault("num", __num)
+ rv = __context.call(func, __singular, __plural, __num)
+ if __context.eval_ctx.autoescape:
+ rv = Markup(rv)
+ # Always treat as a format string, see gettext comment above.
+ return rv % variables # type: ignore
+
+ return ngettext
+
+
+def _make_new_pgettext(func: t.Callable[[str, str], str]) -> t.Callable[..., str]:
+ @pass_context
+ def pgettext(
+ __context: Context, __string_ctx: str, __string: str, **variables: t.Any
+ ) -> str:
+ variables.setdefault("context", __string_ctx)
+ rv = __context.call(func, __string_ctx, __string)
+
+ if __context.eval_ctx.autoescape:
+ rv = Markup(rv)
+
+ # Always treat as a format string, see gettext comment above.
+ return rv % variables # type: ignore
+
+ return pgettext
+
+
+def _make_new_npgettext(
+ func: t.Callable[[str, str, str, int], str]
+) -> t.Callable[..., str]:
+ @pass_context
+ def npgettext(
+ __context: Context,
+ __string_ctx: str,
+ __singular: str,
+ __plural: str,
+ __num: int,
+ **variables: t.Any,
+ ) -> str:
+ variables.setdefault("context", __string_ctx)
+ variables.setdefault("num", __num)
+ rv = __context.call(func, __string_ctx, __singular, __plural, __num)
+
+ if __context.eval_ctx.autoescape:
+ rv = Markup(rv)
+
+ # Always treat as a format string, see gettext comment above.
+ return rv % variables # type: ignore
+
+ return npgettext
+
+
+class InternationalizationExtension(Extension):
+ """This extension adds gettext support to Jinja."""
+
+ tags = {"trans"}
+
+ # TODO: the i18n extension is currently reevaluating values in a few
+ # situations. Take this example:
+ # {% trans count=something() %}{{ count }} foo{% pluralize
+ # %}{{ count }} fooss{% endtrans %}
+ # something is called twice here. One time for the gettext value and
+ # the other time for the n-parameter of the ngettext function.
+
+ def __init__(self, environment: Environment) -> None:
+ super().__init__(environment)
+ environment.globals["_"] = _gettext_alias
+ environment.extend(
+ install_gettext_translations=self._install,
+ install_null_translations=self._install_null,
+ install_gettext_callables=self._install_callables,
+ uninstall_gettext_translations=self._uninstall,
+ extract_translations=self._extract,
+ newstyle_gettext=False,
+ )
+
+ def _install(
+ self, translations: "_SupportedTranslations", newstyle: t.Optional[bool] = None
+ ) -> None:
+ # ugettext and ungettext are preferred in case the I18N library
+ # is providing compatibility with older Python versions.
+ gettext = getattr(translations, "ugettext", None)
+ if gettext is None:
+ gettext = translations.gettext
+ ngettext = getattr(translations, "ungettext", None)
+ if ngettext is None:
+ ngettext = translations.ngettext
+
+ pgettext = getattr(translations, "pgettext", None)
+ npgettext = getattr(translations, "npgettext", None)
+ self._install_callables(
+ gettext, ngettext, newstyle=newstyle, pgettext=pgettext, npgettext=npgettext
+ )
+
+ def _install_null(self, newstyle: t.Optional[bool] = None) -> None:
+ import gettext
+
+ translations = gettext.NullTranslations()
+
+ if hasattr(translations, "pgettext"):
+ # Python < 3.8
+ pgettext = translations.pgettext # type: ignore
+ else:
+
+ def pgettext(c: str, s: str) -> str:
+ return s
+
+ if hasattr(translations, "npgettext"):
+ npgettext = translations.npgettext # type: ignore
+ else:
+
+ def npgettext(c: str, s: str, p: str, n: int) -> str:
+ return s if n == 1 else p
+
+ self._install_callables(
+ gettext=translations.gettext,
+ ngettext=translations.ngettext,
+ newstyle=newstyle,
+ pgettext=pgettext,
+ npgettext=npgettext,
+ )
+
+ def _install_callables(
+ self,
+ gettext: t.Callable[[str], str],
+ ngettext: t.Callable[[str, str, int], str],
+ newstyle: t.Optional[bool] = None,
+ pgettext: t.Optional[t.Callable[[str, str], str]] = None,
+ npgettext: t.Optional[t.Callable[[str, str, str, int], str]] = None,
+ ) -> None:
+ if newstyle is not None:
+ self.environment.newstyle_gettext = newstyle # type: ignore
+ if self.environment.newstyle_gettext: # type: ignore
+ gettext = _make_new_gettext(gettext)
+ ngettext = _make_new_ngettext(ngettext)
+
+ if pgettext is not None:
+ pgettext = _make_new_pgettext(pgettext)
+
+ if npgettext is not None:
+ npgettext = _make_new_npgettext(npgettext)
+
+ self.environment.globals.update(
+ gettext=gettext, ngettext=ngettext, pgettext=pgettext, npgettext=npgettext
+ )
+
+ def _uninstall(self, translations: "_SupportedTranslations") -> None:
+ for key in ("gettext", "ngettext", "pgettext", "npgettext"):
+ self.environment.globals.pop(key, None)
+
+ def _extract(
+ self,
+ source: t.Union[str, nodes.Template],
+ gettext_functions: t.Sequence[str] = GETTEXT_FUNCTIONS,
+ ) -> t.Iterator[
+ t.Tuple[int, str, t.Union[t.Optional[str], t.Tuple[t.Optional[str], ...]]]
+ ]:
+ if isinstance(source, str):
+ source = self.environment.parse(source)
+ return extract_from_ast(source, gettext_functions)
+
+ def parse(self, parser: "Parser") -> t.Union[nodes.Node, t.List[nodes.Node]]:
+ """Parse a translatable tag."""
+ lineno = next(parser.stream).lineno
+
+ context = None
+ context_token = parser.stream.next_if("string")
+
+ if context_token is not None:
+ context = context_token.value
+
+ # find all the variables referenced. Additionally a variable can be
+ # defined in the body of the trans block too, but this is checked at
+ # a later state.
+ plural_expr: t.Optional[nodes.Expr] = None
+ plural_expr_assignment: t.Optional[nodes.Assign] = None
+ num_called_num = False
+ variables: t.Dict[str, nodes.Expr] = {}
+ trimmed = None
+ while parser.stream.current.type != "block_end":
+ if variables:
+ parser.stream.expect("comma")
+
+ # skip colon for python compatibility
+ if parser.stream.skip_if("colon"):
+ break
+
+ token = parser.stream.expect("name")
+ if token.value in variables:
+ parser.fail(
+ f"translatable variable {token.value!r} defined twice.",
+ token.lineno,
+ exc=TemplateAssertionError,
+ )
+
+ # expressions
+ if parser.stream.current.type == "assign":
+ next(parser.stream)
+ variables[token.value] = var = parser.parse_expression()
+ elif trimmed is None and token.value in ("trimmed", "notrimmed"):
+ trimmed = token.value == "trimmed"
+ continue
+ else:
+ variables[token.value] = var = nodes.Name(token.value, "load")
+
+ if plural_expr is None:
+ if isinstance(var, nodes.Call):
+ plural_expr = nodes.Name("_trans", "load")
+ variables[token.value] = plural_expr
+ plural_expr_assignment = nodes.Assign(
+ nodes.Name("_trans", "store"), var
+ )
+ else:
+ plural_expr = var
+ num_called_num = token.value == "num"
+
+ parser.stream.expect("block_end")
+
+ plural = None
+ have_plural = False
+ referenced = set()
+
+ # now parse until endtrans or pluralize
+ singular_names, singular = self._parse_block(parser, True)
+ if singular_names:
+ referenced.update(singular_names)
+ if plural_expr is None:
+ plural_expr = nodes.Name(singular_names[0], "load")
+ num_called_num = singular_names[0] == "num"
+
+ # if we have a pluralize block, we parse that too
+ if parser.stream.current.test("name:pluralize"):
+ have_plural = True
+ next(parser.stream)
+ if parser.stream.current.type != "block_end":
+ token = parser.stream.expect("name")
+ if token.value not in variables:
+ parser.fail(
+ f"unknown variable {token.value!r} for pluralization",
+ token.lineno,
+ exc=TemplateAssertionError,
+ )
+ plural_expr = variables[token.value]
+ num_called_num = token.value == "num"
+ parser.stream.expect("block_end")
+ plural_names, plural = self._parse_block(parser, False)
+ next(parser.stream)
+ referenced.update(plural_names)
+ else:
+ next(parser.stream)
+
+ # register free names as simple name expressions
+ for name in referenced:
+ if name not in variables:
+ variables[name] = nodes.Name(name, "load")
+
+ if not have_plural:
+ plural_expr = None
+ elif plural_expr is None:
+ parser.fail("pluralize without variables", lineno)
+
+ if trimmed is None:
+ trimmed = self.environment.policies["ext.i18n.trimmed"]
+ if trimmed:
+ singular = self._trim_whitespace(singular)
+ if plural:
+ plural = self._trim_whitespace(plural)
+
+ node = self._make_node(
+ singular,
+ plural,
+ context,
+ variables,
+ plural_expr,
+ bool(referenced),
+ num_called_num and have_plural,
+ )
+ node.set_lineno(lineno)
+ if plural_expr_assignment is not None:
+ return [plural_expr_assignment, node]
+ else:
+ return node
+
+ def _trim_whitespace(self, string: str, _ws_re: t.Pattern[str] = _ws_re) -> str:
+ return _ws_re.sub(" ", string.strip())
+
+ def _parse_block(
+ self, parser: "Parser", allow_pluralize: bool
+ ) -> t.Tuple[t.List[str], str]:
+ """Parse until the next block tag with a given name."""
+ referenced = []
+ buf = []
+
+ while True:
+ if parser.stream.current.type == "data":
+ buf.append(parser.stream.current.value.replace("%", "%%"))
+ next(parser.stream)
+ elif parser.stream.current.type == "variable_begin":
+ next(parser.stream)
+ name = parser.stream.expect("name").value
+ referenced.append(name)
+ buf.append(f"%({name})s")
+ parser.stream.expect("variable_end")
+ elif parser.stream.current.type == "block_begin":
+ next(parser.stream)
+ if parser.stream.current.test("name:endtrans"):
+ break
+ elif parser.stream.current.test("name:pluralize"):
+ if allow_pluralize:
+ break
+ parser.fail(
+ "a translatable section can have only one pluralize section"
+ )
+ parser.fail(
+ "control structures in translatable sections are not allowed"
+ )
+ elif parser.stream.eos:
+ parser.fail("unclosed translation block")
+ else:
+ raise RuntimeError("internal parser error")
+
+ return referenced, concat(buf)
+
+ def _make_node(
+ self,
+ singular: str,
+ plural: t.Optional[str],
+ context: t.Optional[str],
+ variables: t.Dict[str, nodes.Expr],
+ plural_expr: t.Optional[nodes.Expr],
+ vars_referenced: bool,
+ num_called_num: bool,
+ ) -> nodes.Output:
+ """Generates a useful node from the data provided."""
+ newstyle = self.environment.newstyle_gettext # type: ignore
+ node: nodes.Expr
+
+ # no variables referenced? no need to escape for old style
+ # gettext invocations only if there are vars.
+ if not vars_referenced and not newstyle:
+ singular = singular.replace("%%", "%")
+ if plural:
+ plural = plural.replace("%%", "%")
+
+ func_name = "gettext"
+ func_args: t.List[nodes.Expr] = [nodes.Const(singular)]
+
+ if context is not None:
+ func_args.insert(0, nodes.Const(context))
+ func_name = f"p{func_name}"
+
+ if plural_expr is not None:
+ func_name = f"n{func_name}"
+ func_args.extend((nodes.Const(plural), plural_expr))
+
+ node = nodes.Call(nodes.Name(func_name, "load"), func_args, [], None, None)
+
+ # in case newstyle gettext is used, the method is powerful
+ # enough to handle the variable expansion and autoescape
+ # handling itself
+ if newstyle:
+ for key, value in variables.items():
+ # the function adds that later anyways in case num was
+ # called num, so just skip it.
+ if num_called_num and key == "num":
+ continue
+ node.kwargs.append(nodes.Keyword(key, value))
+
+ # otherwise do that here
+ else:
+ # mark the return value as safe if we are in an
+ # environment with autoescaping turned on
+ node = nodes.MarkSafeIfAutoescape(node)
+ if variables:
+ node = nodes.Mod(
+ node,
+ nodes.Dict(
+ [
+ nodes.Pair(nodes.Const(key), value)
+ for key, value in variables.items()
+ ]
+ ),
+ )
+ return nodes.Output([node])
+
+
+class ExprStmtExtension(Extension):
+ """Adds a `do` tag to Jinja that works like the print statement just
+ that it doesn't print the return value.
+ """
+
+ tags = {"do"}
+
+ def parse(self, parser: "Parser") -> nodes.ExprStmt:
+ node = nodes.ExprStmt(lineno=next(parser.stream).lineno)
+ node.node = parser.parse_tuple()
+ return node
+
+
+class LoopControlExtension(Extension):
+ """Adds break and continue to the template engine."""
+
+ tags = {"break", "continue"}
+
+ def parse(self, parser: "Parser") -> t.Union[nodes.Break, nodes.Continue]:
+ token = next(parser.stream)
+ if token.value == "break":
+ return nodes.Break(lineno=token.lineno)
+ return nodes.Continue(lineno=token.lineno)
+
+
+class DebugExtension(Extension):
+ """A ``{% debug %}`` tag that dumps the available variables,
+ filters, and tests.
+
+ .. code-block:: html+jinja
+
+ <pre>{% debug %}</pre>
+
+ .. code-block:: text
+
+ {'context': {'cycler': <class 'jinja2.utils.Cycler'>,
+ ...,
+ 'namespace': <class 'jinja2.utils.Namespace'>},
+ 'filters': ['abs', 'attr', 'batch', 'capitalize', 'center', 'count', 'd',
+ ..., 'urlencode', 'urlize', 'wordcount', 'wordwrap', 'xmlattr'],
+ 'tests': ['!=', '<', '<=', '==', '>', '>=', 'callable', 'defined',
+ ..., 'odd', 'sameas', 'sequence', 'string', 'undefined', 'upper']}
+
+ .. versionadded:: 2.11.0
+ """
+
+ tags = {"debug"}
+
+ def parse(self, parser: "Parser") -> nodes.Output:
+ lineno = parser.stream.expect("name:debug").lineno
+ context = nodes.ContextReference()
+ result = self.call_method("_render", [context], lineno=lineno)
+ return nodes.Output([result], lineno=lineno)
+
+ def _render(self, context: Context) -> str:
+ result = {
+ "context": context.get_all(),
+ "filters": sorted(self.environment.filters.keys()),
+ "tests": sorted(self.environment.tests.keys()),
+ }
+
+ # Set the depth since the intent is to show the top few names.
+ return pprint.pformat(result, depth=3, compact=True)
+
+
+def extract_from_ast(
+ ast: nodes.Template,
+ gettext_functions: t.Sequence[str] = GETTEXT_FUNCTIONS,
+ babel_style: bool = True,
+) -> t.Iterator[
+ t.Tuple[int, str, t.Union[t.Optional[str], t.Tuple[t.Optional[str], ...]]]
+]:
+ """Extract localizable strings from the given template node. Per
+ default this function returns matches in babel style that means non string
+ parameters as well as keyword arguments are returned as `None`. This
+ allows Babel to figure out what you really meant if you are using
+ gettext functions that allow keyword arguments for placeholder expansion.
+ If you don't want that behavior set the `babel_style` parameter to `False`
+ which causes only strings to be returned and parameters are always stored
+ in tuples. As a consequence invalid gettext calls (calls without a single
+ string parameter or string parameters after non-string parameters) are
+ skipped.
+
+ This example explains the behavior:
+
+ >>> from jinja2 import Environment
+ >>> env = Environment()
+ >>> node = env.parse('{{ (_("foo"), _(), ngettext("foo", "bar", 42)) }}')
+ >>> list(extract_from_ast(node))
+ [(1, '_', 'foo'), (1, '_', ()), (1, 'ngettext', ('foo', 'bar', None))]
+ >>> list(extract_from_ast(node, babel_style=False))
+ [(1, '_', ('foo',)), (1, 'ngettext', ('foo', 'bar'))]
+
+ For every string found this function yields a ``(lineno, function,
+ message)`` tuple, where:
+
+ * ``lineno`` is the number of the line on which the string was found,
+ * ``function`` is the name of the ``gettext`` function used (if the
+ string was extracted from embedded Python code), and
+ * ``message`` is the string, or a tuple of strings for functions
+ with multiple string arguments.
+
+ This extraction function operates on the AST and is because of that unable
+ to extract any comments. For comment support you have to use the babel
+ extraction interface or extract comments yourself.
+ """
+ out: t.Union[t.Optional[str], t.Tuple[t.Optional[str], ...]]
+
+ for node in ast.find_all(nodes.Call):
+ if (
+ not isinstance(node.node, nodes.Name)
+ or node.node.name not in gettext_functions
+ ):
+ continue
+
+ strings: t.List[t.Optional[str]] = []
+
+ for arg in node.args:
+ if isinstance(arg, nodes.Const) and isinstance(arg.value, str):
+ strings.append(arg.value)
+ else:
+ strings.append(None)
+
+ for _ in node.kwargs:
+ strings.append(None)
+ if node.dyn_args is not None:
+ strings.append(None)
+ if node.dyn_kwargs is not None:
+ strings.append(None)
+
+ if not babel_style:
+ out = tuple(x for x in strings if x is not None)
+
+ if not out:
+ continue
+ else:
+ if len(strings) == 1:
+ out = strings[0]
+ else:
+ out = tuple(strings)
+
+ yield node.lineno, node.node.name, out
+
+
+class _CommentFinder:
+ """Helper class to find comments in a token stream. Can only
+ find comments for gettext calls forwards. Once the comment
+ from line 4 is found, a comment for line 1 will not return a
+ usable value.
+ """
+
+ def __init__(
+ self, tokens: t.Sequence[t.Tuple[int, str, str]], comment_tags: t.Sequence[str]
+ ) -> None:
+ self.tokens = tokens
+ self.comment_tags = comment_tags
+ self.offset = 0
+ self.last_lineno = 0
+
+ def find_backwards(self, offset: int) -> t.List[str]:
+ try:
+ for _, token_type, token_value in reversed(
+ self.tokens[self.offset : offset]
+ ):
+ if token_type in ("comment", "linecomment"):
+ try:
+ prefix, comment = token_value.split(None, 1)
+ except ValueError:
+ continue
+ if prefix in self.comment_tags:
+ return [comment.rstrip()]
+ return []
+ finally:
+ self.offset = offset
+
+ def find_comments(self, lineno: int) -> t.List[str]:
+ if not self.comment_tags or self.last_lineno > lineno:
+ return []
+ for idx, (token_lineno, _, _) in enumerate(self.tokens[self.offset :]):
+ if token_lineno > lineno:
+ return self.find_backwards(self.offset + idx)
+ return self.find_backwards(len(self.tokens))
+
+
+def babel_extract(
+ fileobj: t.BinaryIO,
+ keywords: t.Sequence[str],
+ comment_tags: t.Sequence[str],
+ options: t.Dict[str, t.Any],
+) -> t.Iterator[
+ t.Tuple[
+ int, str, t.Union[t.Optional[str], t.Tuple[t.Optional[str], ...]], t.List[str]
+ ]
+]:
+ """Babel extraction method for Jinja templates.
+
+ .. versionchanged:: 2.3
+ Basic support for translation comments was added. If `comment_tags`
+ is now set to a list of keywords for extraction, the extractor will
+ try to find the best preceding comment that begins with one of the
+ keywords. For best results, make sure to not have more than one
+ gettext call in one line of code and the matching comment in the
+ same line or the line before.
+
+ .. versionchanged:: 2.5.1
+ The `newstyle_gettext` flag can be set to `True` to enable newstyle
+ gettext calls.
+
+ .. versionchanged:: 2.7
+ A `silent` option can now be provided. If set to `False` template
+ syntax errors are propagated instead of being ignored.
+
+ :param fileobj: the file-like object the messages should be extracted from
+ :param keywords: a list of keywords (i.e. function names) that should be
+ recognized as translation functions
+ :param comment_tags: a list of translator tags to search for and include
+ in the results.
+ :param options: a dictionary of additional options (optional)
+ :return: an iterator over ``(lineno, funcname, message, comments)`` tuples.
+ (comments will be empty currently)
+ """
+ extensions: t.Dict[t.Type[Extension], None] = {}
+
+ for extension_name in options.get("extensions", "").split(","):
+ extension_name = extension_name.strip()
+
+ if not extension_name:
+ continue
+
+ extensions[import_string(extension_name)] = None
+
+ if InternationalizationExtension not in extensions:
+ extensions[InternationalizationExtension] = None
+
+ def getbool(options: t.Mapping[str, str], key: str, default: bool = False) -> bool:
+ return options.get(key, str(default)).lower() in {"1", "on", "yes", "true"}
+
+ silent = getbool(options, "silent", True)
+ environment = Environment(
+ options.get("block_start_string", defaults.BLOCK_START_STRING),
+ options.get("block_end_string", defaults.BLOCK_END_STRING),
+ options.get("variable_start_string", defaults.VARIABLE_START_STRING),
+ options.get("variable_end_string", defaults.VARIABLE_END_STRING),
+ options.get("comment_start_string", defaults.COMMENT_START_STRING),
+ options.get("comment_end_string", defaults.COMMENT_END_STRING),
+ options.get("line_statement_prefix") or defaults.LINE_STATEMENT_PREFIX,
+ options.get("line_comment_prefix") or defaults.LINE_COMMENT_PREFIX,
+ getbool(options, "trim_blocks", defaults.TRIM_BLOCKS),
+ getbool(options, "lstrip_blocks", defaults.LSTRIP_BLOCKS),
+ defaults.NEWLINE_SEQUENCE,
+ getbool(options, "keep_trailing_newline", defaults.KEEP_TRAILING_NEWLINE),
+ tuple(extensions),
+ cache_size=0,
+ auto_reload=False,
+ )
+
+ if getbool(options, "trimmed"):
+ environment.policies["ext.i18n.trimmed"] = True
+ if getbool(options, "newstyle_gettext"):
+ environment.newstyle_gettext = True # type: ignore
+
+ source = fileobj.read().decode(options.get("encoding", "utf-8"))
+ try:
+ node = environment.parse(source)
+ tokens = list(environment.lex(environment.preprocess(source)))
+ except TemplateSyntaxError:
+ if not silent:
+ raise
+ # skip templates with syntax errors
+ return
+
+ finder = _CommentFinder(tokens, comment_tags)
+ for lineno, func, message in extract_from_ast(node, keywords):
+ yield lineno, func, message, finder.find_comments(lineno)
+
+
+#: nicer import names
+i18n = InternationalizationExtension
+do = ExprStmtExtension
+loopcontrols = LoopControlExtension
+debug = DebugExtension