55 lines
2.1 KiB
Python
55 lines
2.1 KiB
Python
from django.contrib.messages.storage.base import BaseStorage
|
|
from django.contrib.messages.storage.cookie import CookieStorage
|
|
from django.contrib.messages.storage.session import SessionStorage
|
|
|
|
class FallbackStorage(BaseStorage):
|
|
"""
|
|
Tries to store all messages in the first backend, storing any unstored
|
|
messages in each subsequent backend backend.
|
|
"""
|
|
storage_classes = (CookieStorage, SessionStorage)
|
|
|
|
def __init__(self, *args, **kwargs):
|
|
super(FallbackStorage, self).__init__(*args, **kwargs)
|
|
self.storages = [storage_class(*args, **kwargs)
|
|
for storage_class in self.storage_classes]
|
|
self._used_storages = set()
|
|
|
|
def _get(self, *args, **kwargs):
|
|
"""
|
|
Gets a single list of messages from all storage backends.
|
|
"""
|
|
all_messages = []
|
|
for storage in self.storages:
|
|
messages, all_retrieved = storage._get()
|
|
# If the backend hasn't been used, no more retrieval is necessary.
|
|
if messages is None:
|
|
break
|
|
if messages:
|
|
self._used_storages.add(storage)
|
|
all_messages.extend(messages)
|
|
# If this storage class contained all the messages, no further
|
|
# retrieval is necessary
|
|
if all_retrieved:
|
|
break
|
|
return all_messages, all_retrieved
|
|
|
|
def _store(self, messages, response, *args, **kwargs):
|
|
"""
|
|
Stores the messages, returning any unstored messages after trying all
|
|
backends.
|
|
|
|
For each storage backend, any messages not stored are passed on to the
|
|
next backend.
|
|
"""
|
|
for storage in self.storages:
|
|
if messages:
|
|
messages = storage._store(messages, response,
|
|
remove_oldest=False)
|
|
# Even if there are no more messages, continue iterating to ensure
|
|
# storages which contained messages are flushed.
|
|
elif storage in self._used_storages:
|
|
storage._store([], response)
|
|
self._used_storages.remove(storage)
|
|
return messages
|