Overriding Django admin views and nested transactions

[Dave Hall]

This problem is related to #2227, but has a potentially easier solution.

Because the Django admin site directly decorates it's methods with @commit_on_success, and @commit_on_success is unaware on nested outer transactions, it's currently impossible to override an admin view and maintain data integrity. This is a problem for django-reversion, which augments many of the django admin methods by wrapping them in a revision. Ideally, I would be able to save the primary model and it's associated revision data in a single transaction. Currently, however, the superclass view commits the transaction and thus forces the associated revision data to be saved in it's own transaction.

Obviously, a satisfactory fix for #2227 would solve this. However, this ticket seems to be a bit dead, due to conflicting ways of solving it.

Fixing the problem of overriding admin views is easier, however. My proposed solution is to move the existing @commit_on_success and @csrf_protect decorators off the methods, and apply them in the admin site under AdminSite.admin_view instead. This would mean they are applied after all subclassing has taken place.

I've implemented a tentative patch here:

​https://github.com/etianen/django/commit/6682fc31c810f763f08dcf14505c5762ab1d18a1

[Matthias Kestenholz]

I think that's a good idea.

However, if this was accepted it still needs tests, documentation and probably a note in the BackwardsIncompatibleChanges page.

[Dave Hall]

I'm very happy to write the tests, documentation and the like. Once (if) this gets accepted, I'll get right on it.

[Aymeric Augustin]

Change UI/UX from NULL to False.

[Aymeric Augustin]

Change Easy pickings from NULL to False.

[Aymeric Augustin <aymeric.augustin@…>]

In 14cddf51c5f001bb426ce7f7a83fdc52c8d8aee9:

Merged branch 'database-level-autocommit'.

Fixed #2227: atomic supports nesting.
Fixed #6623: commit_manually is deprecated and atomic doesn't suffer from this defect.
Fixed #8320: the problem wasn't identified, but the legacy transaction management is deprecated.
Fixed #10744: the problem wasn't identified, but the legacy transaction management is deprecated.
Fixed #10813: since autocommit is enabled, it isn't necessary to rollback after errors any more.
Fixed #13742: savepoints are now implemented for SQLite.
Fixed #13870: transaction management in long running processes isn't a problem any more, and it's documented.
Fixed #14970: while it digresses on transaction management, this ticket essentially asks for autocommit on PostgreSQL.
Fixed #15694: atomic supports nesting.
Fixed #17887: autocommit makes it impossible for a connection to stay "idle of transaction".