import re
from django.template import Node,Variable,VariableNode,_render_value_in_context
from django.template import TemplateSyntaxError,TokenParser,Library
from django.template import TOKEN_TEXT,TOKEN_VAR
from django.utils import translation
from django.utils.encoding import force_unicode
register = Library()
class GetAvailableLanguagesNode(Node):
def __init__(self, variable):
self.variable = variable
def render(self, context):
from django.conf import settings
context[self.variable] = [(k, translation.ugettext(v)) for k, v in settings.LANGUAGES]
return ''
class GetCurrentLanguageNode(Node):
def __init__(self, variable):
self.variable = variable
def render(self, context):
context[self.variable] = translation.get_language()
return ''
class GetCurrentLanguageBidiNode(Node):
def __init__(self, variable):
self.variable = variable
def render(self, context):
context[self.variable] = translation.get_language_bidi()
return ''
class TranslateNode(Node):
def __init__(self, filter_expression, noop):
self.noop = noop
self.filter_expression = filter_expression
if isinstance(self.filter_expression.var, basestring):
self.filter_expression.var = Variable(u"'%s'" % self.filter_expression.var)
def render(self, context):
self.filter_expression.var.translate = not self.noop
output = self.filter_expression.resolve(context)
return _render_value_in_context(output, context)
class BlockTranslateNode(Node):
def __init__(self, extra_context, singular, plural=None, countervar=None,
counter=None):
self.extra_context = extra_context
self.singular = singular
self.plural = plural
self.countervar = countervar
self.counter = counter
def render_token_list(self, tokens):
result = []
vars = []
for token in tokens:
if token.token_type == TOKEN_TEXT:
result.append(token.contents)
elif token.token_type == TOKEN_VAR:
result.append(u'%%(%s)s' % token.contents)
vars.append(token.contents)
return ''.join(result), vars
def render(self, context):
tmp_context = {}
for var, val in self.extra_context.items():
tmp_context[var] = val.render(context)
# Update() works like a push(), so corresponding context.pop() is at
# the end of function
context.update(tmp_context)
singular, vars = self.render_token_list(self.singular)
if self.plural and self.countervar and self.counter:
count = self.counter.resolve(context)
context[self.countervar] = count
plural, vars = self.render_token_list(self.plural)
result = translation.ungettext(singular, plural, count)
else:
result = translation.ugettext(singular)
# Escape all isolated '%' before substituting in the context.
result = re.sub(u'%(?!\()', u'%%', result)
data = dict([(v, _render_value_in_context(context[v], context)) for v in vars])
context.pop()
return result % data
def do_get_available_languages(parser, token):
"""
This will store a list of available languages
in the context.
Usage::
{% get_available_languages as languages %}
{% for language in languages %}
...
{% endfor %}
This will just pull the LANGUAGES setting from
your setting file (or the default settings) and
put it into the named variable.
"""
args = token.contents.split()
if len(args) != 3 or args[1] != 'as':
raise TemplateSyntaxError("'get_available_languages' requires 'as variable' (got %r)" % args)
return GetAvailableLanguagesNode(args[2])
def do_get_current_language(parser, token):
"""
This will store the current language in the context.
Usage::
{% get_current_language as language %}
This will fetch the currently active language and
put it's value into the ``language`` context
variable.
"""
args = token.contents.split()
if len(args) != 3 or args[1] != 'as':
raise TemplateSyntaxError("'get_current_language' requires 'as variable' (got %r)" % args)
return GetCurrentLanguageNode(args[2])
def do_get_current_language_bidi(parser, token):
"""
This will store the current language layout in the context.
Usage::
{% get_current_language_bidi as bidi %}
This will fetch the currently active language's layout and
put it's value into the ``bidi`` context variable.
True indicates right-to-left layout, otherwise left-to-right
"""
args = token.contents.split()
if len(args) != 3 or args[1] != 'as':
raise TemplateSyntaxError("'get_current_language_bidi' requires 'as variable' (got %r)" % args)
return GetCurrentLanguageBidiNode(args[2])
def do_translate(parser, token):
"""
This will mark a string for translation and will
translate the string for the current language.
Usage::
{% trans "this is a test" %}
This will mark the string for translation so it will
be pulled out by mark-messages.py into the .po files
and will run the string through the translation engine.
There is a second form::
{% trans "this is a test" noop %}
This will only mark for translation, but will return
the string unchanged. Use it when you need to store
values into forms that should be translated later on.
You can use variables instead of constant strings
to translate stuff you marked somewhere else::
{% trans variable %}
This will just try to translate the contents of
the variable ``variable``. Make sure that the string
in there is something that is in the .po file.
"""
class TranslateParser(TokenParser):
def top(self):
value = self.value()
# Backwards Compatiblity fix:
# FilterExpression does not support single-quoted strings,
# so we make a cheap localized fix in order to maintain
# backwards compatibility with existing uses of ``trans``
# where single quote use is supported.
if value[0] == "'":
pos = None
m = re.match("^'([^']+)'(\|.*$)",value)
if m:
value = '"%s"%s' % (m.group(1).replace('"','\\"'),m.group(2))
elif value[-1] == "'":
value = '"%s"' % value[1:-1].replace('"','\\"')
if self.more():
if self.tag() == 'noop':
noop = True
else:
raise TemplateSyntaxError("only option for 'trans' is 'noop'")
else:
noop = False
return (value, noop)
value, noop = TranslateParser(token.contents).top()
return TranslateNode(parser.compile_filter(value), noop)
def do_block_translate(parser, token):
"""
This will translate a block of text with parameters.
Usage::
{% blocktrans with foo|filter as bar and baz|filter as boo %}
This is {{ bar }} and {{ boo }}.
{% endblocktrans %}
Additionally, this supports pluralization::
{% blocktrans count var|length as count %}
There is {{ count }} object.
{% plural %}
There are {{ count }} objects.
{% endblocktrans %}
This is much like ngettext, only in template syntax.
"""
class BlockTranslateParser(TokenParser):
def top(self):
countervar = None
counter = None
extra_context = {}
while self.more():
tag = self.tag()
if tag == 'with' or tag == 'and':
value = self.value()
if self.tag() != 'as':
raise TemplateSyntaxError("variable bindings in 'blocktrans' must be 'with value as variable'")
extra_context[self.tag()] = VariableNode(
parser.compile_filter(value))
elif tag == 'count':
counter = parser.compile_filter(self.value())
if self.tag() != 'as':
raise TemplateSyntaxError("counter specification in 'blocktrans' must be 'count value as variable'")
countervar = self.tag()
else:
raise TemplateSyntaxError("unknown subtag %s for 'blocktrans' found" % tag)
return (countervar, counter, extra_context)
countervar, counter, extra_context = BlockTranslateParser(token.contents).top()
singular = []
plural = []
while parser.tokens:
token = parser.next_token()
if token.token_type in (TOKEN_VAR, TOKEN_TEXT):
singular.append(token)
else:
break
if countervar and counter:
if token.contents.strip() != 'plural':
raise TemplateSyntaxError("'blocktrans' doesn't allow other block tags inside it")
while parser.tokens:
token = parser.next_token()
if token.token_type in (TOKEN_VAR, TOKEN_TEXT):
plural.append(token)
else:
break
if token.contents.strip() != 'endblocktrans':
raise TemplateSyntaxError("'blocktrans' doesn't allow other block tags (seen %r) inside it" % token.contents)
return BlockTranslateNode(extra_context, singular, plural, countervar,
counter)
register.tag('get_available_languages', do_get_available_languages)
register.tag('get_current_language', do_get_current_language)
register.tag('get_current_language_bidi', do_get_current_language_bidi)
register.tag('trans', do_translate)
register.tag('blocktrans', do_block_translate)
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