| from django.conf import settings |
| from django.contrib.messages.storage import default_storage |
| |
| |
| class MessageMiddleware(object): |
| """ |
| Middleware that handles temporary messages. |
| """ |
| |
| def process_request(self, request): |
| request._messages = default_storage(request) |
| |
| def process_response(self, request, response): |
| """ |
| Updates the storage backend (i.e., saves the messages). |
| |
| If not all messages could not be stored and ``DEBUG`` is ``True``, a |
| ``ValueError`` is raised. |
| """ |
| # A higher middleware layer may return a request which does not contain |
| # messages storage, so make no assumption that it will be there. |
| if hasattr(request, '_messages'): |
| unstored_messages = request._messages.update(response) |
| if unstored_messages and settings.DEBUG: |
| raise ValueError('Not all temporary messages could be stored.') |
| return response |
