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
15096	Add post_form_save signal	James Dabbs	James Dabbs	"Several people (see [http://stackoverflow.com/questions/4432385/django-how-to-save-m2m-data-via-post-save-signal/ stackoverflow], #13950, [http://groups.google.com/group/django-developers/browse_thread/thread/15ac46bb5807bd7a/180d491dc781be49 django-developers]) have had trouble with / questions about model post_save signals and m2m fields. Personally, I've got a model where the objects almost never change, but every time one is added, I need to run a (relatively expensive) callback function which depends on the entire collection of related objects. Unfortunately, the model's post_save signal fires before the m2m fields are populated, and it's wasteful to run the callback function after every m2m_changed, since only the last change matters.

I propose adding a post_form_save signal to any ModelForm that fires after the form's save_m2m method has been called. That will allow the sort of m2m batch processing that I (and [http://stackoverflow.com/questions/4432385/django-how-to-save-m2m-data-via-post-save-signal this gentleman]) are looking for."		closed	Uncategorized	dev		wontfix	signals		Unreviewed	1	1	1	1	0	0