| # -*- coding: utf-8 -*- |
| """ |
| jinja2.ext |
| ~~~~~~~~~~ |
| |
| Jinja extensions allow to add custom tags similar to the way django custom |
| tags work. By default two example extensions exist: an i18n and a cache |
| extension. |
| |
| :copyright: Copyright 2008 by Armin Ronacher. |
| :license: BSD. |
| """ |
| from collections import deque |
| from jinja2 import nodes |
| from jinja2.environment import get_spontaneous_environment |
| from jinja2.runtime import Undefined, concat |
| from jinja2.exceptions import TemplateAssertionError, TemplateSyntaxError |
| from jinja2.utils import contextfunction, import_string, Markup |
| |
| |
| # 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') |
| |
| |
| class ExtensionRegistry(type): |
| """Gives the extension a unique identifier.""" |
| |
| def __new__(cls, name, bases, d): |
| rv = type.__new__(cls, name, bases, d) |
| rv.identifier = rv.__module__ + '.' + rv.__name__ |
| return rv |
| |
| |
| class Extension(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). |
| """ |
| __metaclass__ = ExtensionRegistry |
| |
| #: if this extension parses this is the list of tags it's listening to. |
| tags = set() |
| |
| 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 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) |
| |
| |
| class InternationalizationExtension(Extension): |
| """This extension adds gettext support to Jinja2.""" |
| tags = set(['trans']) |
| |
| def __init__(self, environment): |
| Extension.__init__(self, environment) |
| environment.globals['_'] = contextfunction(lambda c, x: c['gettext'](x)) |
| environment.extend( |
| install_gettext_translations=self._install, |
| install_null_translations=self._install_null, |
| uninstall_gettext_translations=self._uninstall, |
| extract_translations=self._extract |
| ) |
| |
| def _install(self, translations): |
| self.environment.globals.update( |
| gettext=translations.ugettext, |
| ngettext=translations.ungettext |
| ) |
| |
| def _install_null(self): |
| self.environment.globals.update( |
| gettext=lambda x: x, |
| ngettext=lambda s, p, n: (n != 1 and (p,) or (s,))[0] |
| ) |
| |
| 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, basestring): |
| source = self.environment.parse(source) |
| return extract_from_ast(source, gettext_functions) |
| |
| def parse(self, parser): |
| """Parse a translatable tag.""" |
| lineno = parser.stream.next().lineno |
| |
| # 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 |
| variables = {} |
| while parser.stream.current.type is not '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: |
| raise TemplateAssertionError('translatable variable %r defined ' |
| 'twice.' % name.value, name.lineno, |
| parser.filename) |
| |
| # expressions |
| if parser.stream.current.type is 'assign': |
| parser.stream.next() |
| variables[name.value] = var = parser.parse_expression() |
| else: |
| variables[name.value] = var = nodes.Name(name.value, 'load') |
| if plural_expr is None: |
| plural_expr = var |
| |
| parser.stream.expect('block_end') |
| |
| plural = plural_names = 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') |
| |
| # if we have a pluralize block, we parse that too |
| if parser.stream.current.test('name:pluralize'): |
| have_plural = True |
| parser.stream.next() |
| if parser.stream.current.type is not 'block_end': |
| plural_expr = parser.parse_expression() |
| parser.stream.expect('block_end') |
| plural_names, plural = self._parse_block(parser, False) |
| parser.stream.next() |
| referenced.update(plural_names) |
| else: |
| parser.stream.next() |
| |
| # register free names as simple name expressions |
| for var in referenced: |
| if var not in variables: |
| variables[var] = nodes.Name(var, 'load') |
| |
| # no variables referenced? no need to escape |
| if not referenced: |
| singular = singular.replace('%%', '%') |
| if plural: |
| plural = plural.replace('%%', '%') |
| |
| if not have_plural: |
| plural_expr = None |
| elif plural_expr is None: |
| raise TemplateAssertionError('pluralize without variables', |
| lineno, parser.filename) |
| |
| if variables: |
| variables = nodes.Dict([nodes.Pair(nodes.Const(x, lineno=lineno), y) |
| for x, y in variables.items()]) |
| else: |
| variables = None |
| |
| node = self._make_node(singular, plural, variables, plural_expr) |
| node.set_lineno(lineno) |
| return node |
| |
| 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 is 'data': |
| buf.append(parser.stream.current.value.replace('%', '%%')) |
| parser.stream.next() |
| elif parser.stream.current.type is 'variable_begin': |
| parser.stream.next() |
| name = parser.stream.expect('name').value |
| referenced.append(name) |
| buf.append('%%(%s)s' % name) |
| parser.stream.expect('variable_end') |
| elif parser.stream.current.type is 'block_begin': |
| parser.stream.next() |
| if parser.stream.current.test('name:endtrans'): |
| break |
| elif parser.stream.current.test('name:pluralize'): |
| if allow_pluralize: |
| break |
| raise TemplateSyntaxError('a translatable section can ' |
| 'have only one pluralize ' |
| 'section', |
| parser.stream.current.lineno, |
| parser.filename) |
| raise TemplateSyntaxError('control structures in translatable' |
| ' sections are not allowed.', |
| parser.stream.current.lineno, |
| parser.filename) |
| else: |
| assert False, 'internal parser error' |
| |
| return referenced, concat(buf) |
| |
| def _make_node(self, singular, plural, variables, plural_expr): |
| """Generates a useful node from the data provided.""" |
| # 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) |
| |
| # mark the return value as safe if we are in an |
| # environment with autoescaping turned on |
| if self.environment.autoescape: |
| node = nodes.MarkSafe(node) |
| |
| if variables: |
| node = nodes.Mod(node, variables) |
| return nodes.Output([node]) |
| |
| |
| def extract_from_ast(node, gettext_functions=GETTEXT_FUNCTIONS): |
| """Extract localizable strings from the given template node. |
| |
| 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). |
| """ |
| 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, basestring): |
| strings.append(arg.value) |
| else: |
| strings.append(None) |
| |
| if len(strings) == 1: |
| strings = strings[0] |
| else: |
| strings = tuple(strings) |
| yield node.lineno, node.node.name, strings |
| |
| |
| def babel_extract(fileobj, keywords, comment_tags, options): |
| """Babel extraction method for Jinja templates. |
| |
| :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. (Unused) |
| :param options: a dictionary of additional options (optional) |
| :return: an iterator over ``(lineno, funcname, message, comments)`` tuples. |
| (comments will be empty currently) |
| """ |
| encoding = options.get('encoding', 'utf-8') |
| |
| have_trans_extension = False |
| extensions = [] |
| for extension in options.get('extensions', '').split(','): |
| extension = extension.strip() |
| if not extension: |
| continue |
| extension = import_string(extension) |
| if extension is InternationalizationExtension: |
| have_trans_extension = True |
| extensions.append(extension) |
| if not have_trans_extension: |
| extensions.append(InternationalizationExtension) |
| |
| environment = get_spontaneous_environment( |
| options.get('block_start_string', '{%'), |
| options.get('block_end_string', '%}'), |
| options.get('variable_start_string', '{{'), |
| options.get('variable_end_string', '}}'), |
| options.get('comment_start_string', '{#'), |
| options.get('comment_end_string', '#}'), |
| options.get('line_statement_prefix') or None, |
| options.get('trim_blocks', '').lower() in ('1', 'on', 'yes', 'true'), |
| tuple(extensions), |
| # fill with defaults so that environments are shared |
| # with other spontaneus environments. The rest of the |
| # arguments are optimizer, undefined, finalize, autoescape, |
| # loader, cache size and auto reloading setting |
| True, Undefined, None, False, None, 0, False |
| ) |
| |
| node = environment.parse(fileobj.read().decode(encoding)) |
| for lineno, func, message in extract_from_ast(node, keywords): |
| yield lineno, func, message, [] |
| |
| |
| #: nicer import names |
| i18n = InternationalizationExtension |