Added middleware for handling language changes

cms/envs/common.py

@@ -462,6 +462,7 @@ INSTALLED_APPS = (
 
     # User preferences
     'user_api',
+    'django_openid_auth',
 )
 
 

common/djangoapps/user_api/middleware.py

@@ -0,0 +1,27 @@
+"""
+Middleware for UserPreferences
+"""
+
+from django.utils.translation.trans_real import parse_accept_lang_header
+
+from user_api.models import UserPreference, LANGUAGE_KEY
+
+
+class UserPreferenceMiddleware(object):
+    """
+    Middleware for user preferences.
+
+    Ensures that, once set, a user's preferences are reflected in the page
+    whenever they are logged in.
+    """
+
+    def process_request(self, request):
+        """
+        If a user's UserPreference contains a language preference,
+        stick that preference in the session.
+        """
+
+        query = UserPreference.objects.filter(user=request.user, key=LANGUAGE_KEY)
+        if query.exists():
+            # there should only be one result for query
+            request.session['django_language'] = query[0].value