users: Help set language cookie when user profile is edited

This patch only ensures that response object is send along with set_language()
call. In later changes, response object can be used by set_language() to set the
language cookie.

Tests:

- Relevant functional tests pass.

- Edit current user's language. The language is immediately set.

- Edit another user's language. The language of the current session is not changed.

Signed-off-by: Sunil Mohan Adapa <sunil@medhas.org>
Reviewed-by: James Valleroy <jvalleroy@mailbox.org>

plinth/modules/users/forms.py

@@ -19,7 +19,6 @@ from plinth import actions
 from plinth.errors import ActionError
 from plinth.modules import first_boot
 from plinth.modules.security import set_restricted_access
-from plinth.translation import set_language
 from plinth.utils import is_user_admin
 
 from . import get_last_admin_user
@@ -244,10 +243,6 @@ class UserUpdateForm(ValidNewUsernameCheckMixin, PasswordConfirmForm,
         auth_username = self.request.user.username
         confirm_password = self.cleaned_data['confirm_password']
 
-        # If user is updating their own profile then only translate the pages
-        if self.username == auth_username:
-            set_language(self.request, None, user.userprofile.language)
-
         if commit:
             user.save()
             self.save_m2m()

plinth/modules/users/views.py

@@ -13,7 +13,7 @@ from django.utils.translation import gettext_lazy
 from django.views.generic.edit import (CreateView, DeleteView, FormView,
                                        UpdateView)
 
-from plinth import actions
+from plinth import actions, translation
 from plinth.errors import ActionError
 from plinth.modules import first_boot
 from plinth.utils import is_user_admin
@@ -108,6 +108,18 @@ class UserUpdate(ContextMixin, SuccessMessageMixin, UpdateView):
         """Return the URL to redirect to in case of successful updation."""
         return reverse('users:edit', kwargs={'slug': self.object.username})
 
+    def form_valid(self, form):
+        """Set the user language if necessary."""
+        response = super().form_valid(form)
+
+        # If user is updating their own profile then set the language for
+        # current session too.
+        if self.object.username == self.request.user.username:
+            translation.set_language(self.request, response,
+                                     self.request.user.userprofile.language)
+
+        return response
+
 
 class UserDelete(ContextMixin, DeleteView):
     """Handle deleting users, showing a confirmation dialog first.