BaseModelFormSet and BaseInlineFormSet should call ModelForm.save() when saving objects

[drozzy@…]

The most current code is at ​http://github.com/jkocherhans/django/tree/formset-updates

This introduces some backwards incompatibilities for people who overrode either type of formset's __init__ method, but this is how I would have written the model formset code if we'd actually had modelforms first. This doesn't really solve any specific problems that I know of.

[Malcolm Tredinnick]

Child forms don't always have enough information to save themselves in the situation when you're adding related elements to some other model: the related elements need to know which related model id to use, for example. If you look at the logic in model formsets (and you're only talking about model formsets here, since normal formsets don't have a save() method), you'll see that there's quite a bit of interaction between information that exists only on the formset object and the forms itself.

If you can come up with some patch that works in all cases and is obviously neater than the current code, then reopen the ticket, but this is currently a bit too ill-defined to be a ticket we can resolve.

[jkocherhans]

Fixed a typo

[jkocherhans]

(In [10190]) Fixed #9284. Fixed #8813. BaseModelFormSet now calls ModelForm.save().
This is backwards-incompatible if you were doing things to 'initial' in BaseModelFormSet.init, or if you relied on the internal _total_form_count or _initial_form_count attributes of BaseFormSet. Those attributes are now public methods.

[jashugan]

This looks excellent. Thanks!