Django: Remove message before they are displayed - django

Question

I know this question sounds weird, but please, let me explain myself.
I'm using a decorator to make a message persist until the user actually dismisses it (like the behavior of stack overflow's messages). The problem is, as a result of this, the message gets added before the user signs out, and so the message gets displayed right after the user logs out. I'm wondering what the best way to remove the message in the logout view is. I've thought of two ways to do this, and am wondering if anyone can think of a better one.
I'm currently favoring this:
storage = messages.get_messages(request)
storage.used = True
Over this:
storage = messages.get_messages(request)
del storage._loaded_messages[0]
To me the second way seems more explicit, even though it is uglier: my intention is to remove the currently loaded messages and this makes that clear. The first way employs a means by which the messages will be cleared as a side effect ... but at least it doesn't rely upon a dunder variable ... what do you guys think?

Answer 1

I had to use 2 of the solutions proposed above toghether as no one alone was enought:
storage = messages.get_messages(request)
for _ in storage:
pass
if len(storage._loaded_messages) == 1:
del storage._loaded_messages[0]
As far as the accepted solution I can loop over the messages several time
and I see that the messages don't seem to be "consumed"

Answer 2

I like this simpler approach for clearing out the underlying iterator, since I actually wanted to add a new message in the place of a standard Django message.
list(messages.get_messages(request))

Answer 3

For the sake of resolution I'm going to mark the method I went with as "The Answer". Thanks to those who commented.
I went with this:
storage = messages.get_messages(request)
storage.used = True
Because it seemed cleaner, was easier to test, and conformed with the general practices of the rest of the project.

Answer 4

If your logout view always redirects to a "logout page", then you can just change your logout template to hide your messages.
e.g., in template:
{% block extra-header %}
<style type="text/css">
#message-id { display: none; }
</style>
{% endblock %}
It feels a little 'hacky' but I think it's certainly less hacky than your #2.

Answer 5

For me in Django 1.5 and session message storage accepted method dit not the trick.
I needed to use:
storage = messages.get_messages(request)
for _ in storage:
pass
To get rid of messages from storage.

Answer 6

One way of doing the same thing in Django Admin (tested with Django==1.11.6) is to override response_post_*.
def response_post_save_change(self, request, obj):
storage = messages.get_messages(request)
storage._loaded_messages = []
return super().response_post_save_change(request, obj)
And if you want to keep only your custom messages (e.g. added in save_model or any other overridden method) remove the last queued message (which is the one Django ads by default).
def response_post_save_change(self, request, obj):
storage = messages.get_messages(request)
if len(storage._queued_messages) > 1:
del storage._queued_messages[-1]
return super().response_post_save_change(request, obj)