`BaseFormSet.is_valid` should call it's underlying forms' `is_valid`

[Simon Charette]

The actual implementation of BaseFormSet.is_valid checks if any of it's underlying forms have errors which short circuits any extra check-ups that could be defined in the form is_valid method.

i,e.

class MyForm(Form):

  def is_valid(self):
    is_valid = super(MyForm, self).is_valid()
    print 'I was called'
    return is_valid and self.other_non_field_related_validation()

MyFormSet = formset_factory(MyForm)

# In this case calling MyFormSet(data).is_valid() will never print 'I was called'.

I'm submitting this as a bug since I don't think that's the expected behaviour.

[Simon Charette]

Created a ​pull request which passes all tests on sqlite.

[Simon Charette]

Here's the workaround I use while this is not fixed:

from django.forms.formsets import BaseFormSet


class BaseValidateFormSet(BaseFormSet):
    
    def is_valid(self):
        is_valid = super(BaseValidateFormSet, self).is_valid()
        for form in self:
            is_valid &= form.is_valid() or (self.can_delete and
                                            self._should_delete_form(form))
        return is_valid

[foonicorn]

Tests for charettes' patch

[Claude Paroz <claude@…>]

In 66dfcc10b37120638894cb412a15274b17cfb360:

Fixed #18574 -- Make BaseFormSet.is_valid call its underlying forms' is_valid

Thanks Simon Charette for the report and the initial patch.

[Claude Paroz <claude@…>]

In 67bddc0b7b6468abe875f30e4b70560787b5eb5b:

[1.5.x] Fixed #18574 -- Make BaseFormSet.is_valid call its underlying forms' is_valid

Thanks Simon Charette for the report and the initial patch.
Backport of 66dfcc10b from master.