"This is the locale selecting middleware that will look at accept headers"
from django.conf import settings
from django.core.urlresolvers import (is_valid_path, get_resolver,
LocaleRegexURLResolver)
from django.http import HttpResponseRedirect
from django.utils.cache import patch_vary_headers
from django.utils import translation
from django.utils.datastructures import SortedDict
[docs]class LocaleMiddleware(object):
"""
This is a very simple middleware that parses a request
and decides what translation object to install in the current
thread context. This allows pages to be dynamically
translated to the language the user desires (if the language
is available, of course).
"""
def __init__(self):
self._supported_languages = SortedDict(settings.LANGUAGES)
self._is_language_prefix_patterns_used = False
for url_pattern in get_resolver(None).url_patterns:
if isinstance(url_pattern, LocaleRegexURLResolver):
self._is_language_prefix_patterns_used = True
break
def process_request(self, request):
check_path = self.is_language_prefix_patterns_used()
language = translation.get_language_from_request(
request, check_path=check_path)
translation.activate(language)
request.LANGUAGE_CODE = translation.get_language()
def process_response(self, request, response):
language = translation.get_language()
language_from_path = translation.get_language_from_path(
request.path_info, supported=self._supported_languages
)
if (response.status_code == 404 and not language_from_path
and self.is_language_prefix_patterns_used()):
urlconf = getattr(request, 'urlconf', None)
language_path = '/%s%s' % (language, request.path_info)
path_valid = is_valid_path(language_path, urlconf)
if (not path_valid and settings.APPEND_SLASH
and not language_path.endswith('/')):
path_valid = is_valid_path("%s/" % language_path, urlconf)
if path_valid:
language_url = "%s://%s/%s%s" % (
'https' if request.is_secure() else 'http',
request.get_host(), language, request.get_full_path())
return HttpResponseRedirect(language_url)
if not (self.is_language_prefix_patterns_used()
and language_from_path):
patch_vary_headers(response, ('Accept-Language',))
if 'Content-Language' not in response:
response['Content-Language'] = language
return response
def is_language_prefix_patterns_used(self):
"""
Returns `True` if the `LocaleRegexURLResolver` is used
at root level of the urlpatterns, else it returns `False`.
"""
return self._is_language_prefix_patterns_used
Jul 20, 2015