| """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 .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 |
| |
| # I18N functions available in Jinja templates. If the I18N library |
| # provides ugettext, it will be assigned to gettext. |
| 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 = f"{rv.__module__}.{rv.__name__}" |
| return rv |
| |
| |
| class Extension(metaclass=ExtensionRegistry): |
| """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): |
| # 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 |
| self._install_callables(gettext, ngettext, newstyle) |
| |
| def _install_null(self, newstyle=None): |
| self._install_callables( |
| lambda x: x, lambda s, p, n: s if n == 1 else p, 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, str): |
| 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( |
| f"translatable variable {name.value!r} defined twice.", |
| 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( |
| f"unknown variable {name.value!r} for pluralization", |
| 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(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, 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 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): |
| 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): |
| 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, 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. |
| """ |
| 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, 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: |
| 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: |
| """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 |