Django Forms BooleanField单元测试用例有什么问题？

Question

I'm totally stuck here. Why does this test case fail?

class BogusForm(forms.Form):
    bogus_bool = forms.BooleanField() 

class TestBogusForm(TestCase):

    def test_bogus_false(self):
        query_dict = QueryDict('', mutable=True)
        query_dict.update({'bogus_bool': False})
        bogus_form = BogusForm(query_dict)
        self.assertTrue(bogus_form.is_valid())

It fails form field validation, but only if bogus_bool is False when I update the QueryDict . If I say:

query_dict.update({'bogus_bool': True})

Then it passes validation. What's going on here? Is this a bug in Django Forms?

If I look at the QueryDict before I pass it to the BogusForm constructor, it looks like this:

<QueryDict: {u'bogus_bool': [False]}>

Which looks totally legit and correct to me.

Answer 1

From django's documentation

Since all Field subclasses have required=True by default, the validation condition here is important. If you want to include a boolean in your form that can be either True or False (eg a checked or unchecked checkbox), you must remember to pass in required=False when creating the BooleanField.

Answer 2

I agree that this is incorrect behavior.

This should do for a specific field:

class BogusForm(forms.Form):
    bogus_bool = forms.BooleanField(required=False)

    def clean_bogus_bool(self):
        field_name = 'bogus_bool'
        if field_name not in self.data:
            raise forms.ValidationError("This field is required.")
        return self.cleaned_data[field_name]

This should do it for all bool fields on the form:

class BooleanFieldsRequiredMixin(forms.Form):
    def clean(self):
        for field_name, field in self.fields.iteritems():
            # Only BooleanField not subclasses of it.
            if type(field) is not forms.BooleanField:
                continue

            if field_name not in self.data:
                self._errors[field_name] = self.error_class(["This field is required."])

        return super(BooleanFieldsRequiredMixin, self).clean()


class BogusForm(BooleanFieldsRequiredMixin, forms.Form):
    bogus_bool = forms.BooleanField(required=False)

There is a way to make this nicer by not requiring that required=False bit on the boolean field, but it's not worth the effort at the moment.

Answer 3

It's because your bogus_bool is a required field by default.

class BogusForm(forms.Form):
    bogus_bool = forms.BooleanField(required=False)

should do the trick.