Django formsets: make first required?

Question

These formsets are exhibiting exactly the opposite behavior that I want.

My view is set up like this:

def post(request): # TODO: handle vehi         


        

Answer 1

Well... this makes the first form required.

class RequiredFormSet(BaseFormSet):
    def clean(self):
        if any(self.errors):
            return
        if not self.forms[0].has_changed():
            raise forms.ValidationError('Please add at least one vehicle.') 

Only "problem" is that if there are 0 forms, then the clean method doesn't seem to get called at all, so I don't know how to check if there are 0. Really...this should never happen though (except that my JS has a bug in it, allowing you to remove all the forms).