more formset adventures
Michael Stevens
I'm using a ModelFormset created with lineformset_factory.
When I click delete on one of the records and save the formset, it
successfully removes the associated db record, but if I redisplay the
formset after the save, it's still showing the now removed form.
I've modified my code to recreate the formset from the db immediately
after the save:
if foo_formset.is_valid():
foo_formset.save()
foo_formset = FooInlineFormset(instance=bar, prefix='foo')
and it does what I expect, but shouldn't it be in the right state
after the save?
Looking at the code I think the problem is that BaseModelFormSet
doesn't do anything with deleted forms after it deletes the underlying
model object - I'm expecting them to be removed from the formset as
well.
I'm running a svn checkout of 1.1.
Is this a bug, or are my expectations dodgy? :)
Michael
Karen Tracey
The usual pattern for form handling (http://docs.djangoproject.com/en/dev/topics/forms/#using-a-form-in-a-view) uses an HttpRedirect at the end of the is_valid() leg of handling POST data. So generally when you have successfully performed some action requested in a form, you are not expected to be re-displaying the form that triggered that action. Thus I think your expectations are off. Doing work to make the form "correctly" re-display after a .save() would be a waste of cycles in the normal case.
This pattern is not Django-specific. It is a general web application pattern that avoids duplicate POSTs resulting form a user reloading a page and confusing alert boxes when a user tried to reload a page resulting from a POST.
Karen