id	summary	reporter	owner	description	type	status	component	version	severity	resolution	keywords	cc	stage	has_patch	needs_docs	needs_tests	needs_better_patch	easy	ui_ux
24215	Refactor of lazy model operations	Alex Hill	nobody	"I dealt with `add_lazy_relation()` a few months ago working on Mezzanine and I thought it could use some detangling.

Now that the list of pending operations is stored in the `Apps` class, it makes sense to put the related methods on that class as well. Running a function when a model is loaded seems an appropriate job for the app registry object.

I've introduced a more generic API, whereby a user-supplied function can be called once any number of models are ready, with those freshly-loaded models as its arguments (plus optional kwargs), a helper function for related models, and the old `add_lazy_relation()` reimplemented in terms of the new API with a deprecation warning.

New pull request, now targeting master rather than 1.8, at https://github.com/django/django/pull/4130"	Cleanup/optimization	closed	Database layer (models, ORM)	dev	Normal	fixed		cmawebsite@…	Accepted	1	0	0	0	0	0