Source code for django.middleware.locale

from django.conf import settings
from django.conf.urls.i18n import is_language_prefix_patterns_used
from django.http import HttpResponseRedirect
from django.urls import get_script_prefix, is_valid_path
from django.utils import translation
from django.utils.cache import patch_vary_headers
from django.utils.deprecation import MiddlewareMixin


[docs]class LocaleMiddleware(MiddlewareMixin): """ Parse a request and decide 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). """ response_redirect_class = HttpResponseRedirect def get_fallback_language(self, request): """ Return the fallback language for the current request based on the settings. If LANGUAGE_CODE is a variant not included in the supported languages, get_fallback_language() will try to fallback to a supported generic variant. Can be overridden to have a fallback language depending on the request, e.g. based on top level domain. """ try: return translation.get_supported_language_variant(settings.LANGUAGE_CODE) except LookupError: return settings.LANGUAGE_CODE def process_request(self, request): urlconf = getattr(request, "urlconf", settings.ROOT_URLCONF) i18n_patterns_used, _ = is_language_prefix_patterns_used(urlconf) language = translation.get_language_from_request( request, check_path=i18n_patterns_used ) if not language: language = self.get_fallback_language(request) 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) language_from_request = translation.get_language_from_request(request) urlconf = getattr(request, "urlconf", settings.ROOT_URLCONF) ( i18n_patterns_used, prefixed_default_language, ) = is_language_prefix_patterns_used(urlconf) if ( response.status_code == 404 and not language_from_path and i18n_patterns_used and (prefixed_default_language or language_from_request) ): # Maybe the language code is missing in the URL? Try adding the # language prefix and redirecting to that URL. language_path = "/%s%s" % (language, request.path_info) path_valid = is_valid_path(language_path, urlconf) path_needs_slash = not path_valid and ( settings.APPEND_SLASH and not language_path.endswith("/") and is_valid_path("%s/" % language_path, urlconf) ) if path_valid or path_needs_slash: script_prefix = get_script_prefix() # Insert language after the script prefix and before the # rest of the URL language_url = request.get_full_path( force_append_slash=path_needs_slash ).replace(script_prefix, "%s%s/" % (script_prefix, language), 1) # Redirect to the language-specific URL as detected by # get_language_from_request(). HTTP caches may cache this # redirect, so add the Vary header. redirect = self.response_redirect_class(language_url) patch_vary_headers(redirect, ("Accept-Language", "Cookie")) return redirect if not (i18n_patterns_used and language_from_path): patch_vary_headers(response, ("Accept-Language",)) response.headers.setdefault("Content-Language", language) return response