request.user cached value does not track request.session change

[Vlada Macek]

During the Single-Sign On technique implementation I came to the need of replacing request.session with a new session or just setting request.session = None.

The descriptor in AuthenticationMiddleware nevertheless does not remember the session for which it sets the request._cached_user.

IMHO, the descriptor should cache the session key when it saves the _cached_user and allow _cached_user to be used only when the session key did not unchange.

Currently everyone who changes the session during the request processing HAS to dig into the AuthenticationMiddleware internals and modify the _cached_user to get valid request.user. That's hard to maintain.

I can offer the patch, but would like to get some response first.

[Melvyn Sopacua]

Submitter will provide patch if feature is considered useful.

[Aymeric Augustin]

I'm sorry, but if replacing request.session isn't supported. It isn't possible to anticipate the side effects in general. It's up to you to deal with the specific consequences in your project.

[Vlada Macek]

Thank you for the answer. I try to understand your position.

In my humble opinion every piece of code maintaining any cached value should be clever enough to track the cached value validity (or at least support such testing). It looks like it's currently the only thing standing in the way of supporting request.session replacing (which IMO is not too shameful technique by itself).

[Aymeric Augustin]

You can write to django-developers and see if other people would be interested by this change.