build test

venv/lib/python3.7/site-packages/jinja2/ext.py

@@ -0,0 +1,704 @@
+# -*- coding: utf-8 -*-
+"""Extension API for adding custom tags and behavior."""
+import pprint
+import re
+from sys import version_info
+
+from markupsafe import Markup
+
+from . import nodes
+from ._compat import iteritems
+from ._compat import string_types
+from ._compat import with_metaclass
+from .defaults import BLOCK_END_STRING
+from .defaults import BLOCK_START_STRING
+from .defaults import COMMENT_END_STRING
+from .defaults import COMMENT_START_STRING
+from .defaults import KEEP_TRAILING_NEWLINE
+from .defaults import LINE_COMMENT_PREFIX
+from .defaults import LINE_STATEMENT_PREFIX
+from .defaults import LSTRIP_BLOCKS
+from .defaults import NEWLINE_SEQUENCE
+from .defaults import TRIM_BLOCKS
+from .defaults import VARIABLE_END_STRING
+from .defaults import VARIABLE_START_STRING
+from .environment import Environment
+from .exceptions import TemplateAssertionError
+from .exceptions import TemplateSyntaxError
+from .nodes import ContextReference
+from .runtime import concat
+from .utils import contextfunction
+from .utils import import_string
+
+# the only real useful gettext functions for a Jinja template.  Note
+# that ugettext must be assigned to gettext as Jinja doesn't support
+# non unicode strings.
+GETTEXT_FUNCTIONS = ("_", "gettext", "ngettext")
+
+_ws_re = re.compile(r"\s*\n\s*")
+
+
+class ExtensionRegistry(type):
+    """Gives the extension an unique identifier."""
+
+    def __new__(mcs, name, bases, d):
+        rv = type.__new__(mcs, name, bases, d)
+        rv.identifier = rv.__module__ + "." + rv.__name__
+        return rv
+
+
+class Extension(with_metaclass(ExtensionRegistry, object)):
+    """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).
+    """
+
+    #: if this extension parses this is the list of tags it's listening to.
+    tags = 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):
+        self.environment = environment
+
+    def bind(self, environment):
+        """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, name, filename=None):
+        """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):
+        """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):
+        """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, lineno=None):
+        """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, args=None, kwargs=None, dyn_args=None, dyn_kwargs=None, lineno=None
+    ):
+        """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,
+        )
+
+
+@contextfunction
+def _gettext_alias(__context, *args, **kwargs):
+    return __context.call(__context.resolve("gettext"), *args, **kwargs)
+
+
+def _make_new_gettext(func):
+    @contextfunction
+    def gettext(__context, __string, **variables):
+        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
+
+    return gettext
+
+
+def _make_new_ngettext(func):
+    @contextfunction
+    def ngettext(__context, __singular, __plural, __num, **variables):
+        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
+
+    return ngettext
+
+
+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):
+        Extension.__init__(self, 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, newstyle=None):
+        gettext = getattr(translations, "ugettext", None)
+        if gettext is None:
+            gettext = translations.gettext
+        ngettext = getattr(translations, "ungettext", None)
+        if ngettext is None:
+            ngettext = translations.ngettext
+        self._install_callables(gettext, ngettext, newstyle)
+
+    def _install_null(self, newstyle=None):
+        self._install_callables(
+            lambda x: x, lambda s, p, n: (n != 1 and (p,) or (s,))[0], newstyle
+        )
+
+    def _install_callables(self, gettext, ngettext, newstyle=None):
+        if newstyle is not None:
+            self.environment.newstyle_gettext = newstyle
+        if self.environment.newstyle_gettext:
+            gettext = _make_new_gettext(gettext)
+            ngettext = _make_new_ngettext(ngettext)
+        self.environment.globals.update(gettext=gettext, ngettext=ngettext)
+
+    def _uninstall(self, translations):
+        for key in "gettext", "ngettext":
+            self.environment.globals.pop(key, None)
+
+    def _extract(self, source, gettext_functions=GETTEXT_FUNCTIONS):
+        if isinstance(source, string_types):
+            source = self.environment.parse(source)
+        return extract_from_ast(source, gettext_functions)
+
+    def parse(self, parser):
+        """Parse a translatable tag."""
+        lineno = next(parser.stream).lineno
+        num_called_num = False
+
+        # 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 = None
+        plural_expr_assignment = None
+        variables = {}
+        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
+
+            name = parser.stream.expect("name")
+            if name.value in variables:
+                parser.fail(
+                    "translatable variable %r defined twice." % name.value,
+                    name.lineno,
+                    exc=TemplateAssertionError,
+                )
+
+            # expressions
+            if parser.stream.current.type == "assign":
+                next(parser.stream)
+                variables[name.value] = var = parser.parse_expression()
+            elif trimmed is None and name.value in ("trimmed", "notrimmed"):
+                trimmed = name.value == "trimmed"
+                continue
+            else:
+                variables[name.value] = var = nodes.Name(name.value, "load")
+
+            if plural_expr is None:
+                if isinstance(var, nodes.Call):
+                    plural_expr = nodes.Name("_trans", "load")
+                    variables[name.value] = plural_expr
+                    plural_expr_assignment = nodes.Assign(
+                        nodes.Name("_trans", "store"), var
+                    )
+                else:
+                    plural_expr = var
+                num_called_num = name.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":
+                name = parser.stream.expect("name")
+                if name.value not in variables:
+                    parser.fail(
+                        "unknown variable %r for pluralization" % name.value,
+                        name.lineno,
+                        exc=TemplateAssertionError,
+                    )
+                plural_expr = variables[name.value]
+                num_called_num = name.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 var in referenced:
+            if var not in variables:
+                variables[var] = nodes.Name(var, "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,
+            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, _ws_re=_ws_re):
+        return _ws_re.sub(" ", string.strip())
+
+    def _parse_block(self, parser, allow_pluralize):
+        """Parse until the next block tag with a given name."""
+        referenced = []
+        buf = []
+        while 1:
+            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("%%(%s)s" % name)
+                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, plural, variables, plural_expr, vars_referenced, num_called_num
+    ):
+        """Generates a useful node from the data provided."""
+        # no variables referenced?  no need to escape for old style
+        # gettext invocations only if there are vars.
+        if not vars_referenced and not self.environment.newstyle_gettext:
+            singular = singular.replace("%%", "%")
+            if plural:
+                plural = plural.replace("%%", "%")
+
+        # singular only:
+        if plural_expr is None:
+            gettext = nodes.Name("gettext", "load")
+            node = nodes.Call(gettext, [nodes.Const(singular)], [], None, None)
+
+        # singular and plural
+        else:
+            ngettext = nodes.Name("ngettext", "load")
+            node = nodes.Call(
+                ngettext,
+                [nodes.Const(singular), nodes.Const(plural), plural_expr],
+                [],
+                None,
+                None,
+            )
+
+        # in case newstyle gettext is used, the method is powerful
+        # enough to handle the variable expansion and autoescape
+        # handling itself
+        if self.environment.newstyle_gettext:
+            for key, value in iteritems(variables):
+                # 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 = set(["do"])
+
+    def parse(self, parser):
+        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 = set(["break", "continue"])
+
+    def parse(self, parser):
+        token = next(parser.stream)
+        if token.value == "break":
+            return nodes.Break(lineno=token.lineno)
+        return nodes.Continue(lineno=token.lineno)
+
+
+class WithExtension(Extension):
+    pass
+
+
+class AutoEscapeExtension(Extension):
+    pass
+
+
+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):
+        lineno = parser.stream.expect("name:debug").lineno
+        context = ContextReference()
+        result = self.call_method("_render", [context], lineno=lineno)
+        return nodes.Output([result], lineno=lineno)
+
+    def _render(self, context):
+        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.
+        if version_info[:2] >= (3, 4):
+            return pprint.pformat(result, depth=3, compact=True)
+        else:
+            return pprint.pformat(result, depth=3)
+
+
+def extract_from_ast(node, gettext_functions=GETTEXT_FUNCTIONS, babel_style=True):
+    """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 itself (a ``unicode`` object, or a tuple
+       of ``unicode`` objects 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.
+    """
+    for node in node.find_all(nodes.Call):
+        if (
+            not isinstance(node.node, nodes.Name)
+            or node.node.name not in gettext_functions
+        ):
+            continue
+
+        strings = []
+        for arg in node.args:
+            if isinstance(arg, nodes.Const) and isinstance(arg.value, string_types):
+                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:
+            strings = tuple(x for x in strings if x is not None)
+            if not strings:
+                continue
+        else:
+            if len(strings) == 1:
+                strings = strings[0]
+            else:
+                strings = tuple(strings)
+        yield node.lineno, node.node.name, strings
+
+
+class _CommentFinder(object):
+    """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, comment_tags):
+        self.tokens = tokens
+        self.comment_tags = comment_tags
+        self.offset = 0
+        self.last_lineno = 0
+
+    def find_backwards(self, offset):
+        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):
+        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, keywords, comment_tags, options):
+    """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 = set()
+    for extension in options.get("extensions", "").split(","):
+        extension = extension.strip()
+        if not extension:
+            continue
+        extensions.add(import_string(extension))
+    if InternationalizationExtension not in extensions:
+        extensions.add(InternationalizationExtension)
+
+    def getbool(options, key, default=False):
+        return options.get(key, str(default)).lower() in ("1", "on", "yes", "true")
+
+    silent = getbool(options, "silent", True)
+    environment = Environment(
+        options.get("block_start_string", BLOCK_START_STRING),
+        options.get("block_end_string", BLOCK_END_STRING),
+        options.get("variable_start_string", VARIABLE_START_STRING),
+        options.get("variable_end_string", VARIABLE_END_STRING),
+        options.get("comment_start_string", COMMENT_START_STRING),
+        options.get("comment_end_string", COMMENT_END_STRING),
+        options.get("line_statement_prefix") or LINE_STATEMENT_PREFIX,
+        options.get("line_comment_prefix") or LINE_COMMENT_PREFIX,
+        getbool(options, "trim_blocks", TRIM_BLOCKS),
+        getbool(options, "lstrip_blocks", LSTRIP_BLOCKS),
+        NEWLINE_SEQUENCE,
+        getbool(options, "keep_trailing_newline", KEEP_TRAILING_NEWLINE),
+        frozenset(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
+
+    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
+with_ = WithExtension
+autoescape = AutoEscapeExtension
+debug = DebugExtension