How to remove a field from the parent Form in a subclass?
You can alter the fields in a subclass by overriding the init method:
class LoginFormWithoutNickname(LoginForm): def __init__(self, *args, **kwargs): super(LoginFormWithoutNickname, self).__init__(*args, **kwargs) self.fields.pop('nickname')
Django 1.7 addressed this in commit b16dd1fe019 for ticket #8620. In Django 1.7, it becomes possible to do nickname = None
in the subclass as the OP suggests. From the documentation changes in the commit:
It's possible to opt-out from a
Field
inherited from a parent class by shadowing it. While any non-Field
value works for this purpose, it's recommended to useNone
to make it explicit that a field is being nullified.
I found that, please comment if interested.
(in Django 1.7.4)extending forms, with following code:
class MyForm(forms.ModelForm): def __init__(self, *args, **kwargs): super(MyForm, self).__init__(*args, **kwargs) for key, field in self.fields.iteritems(): self.fields[key].required = False class Meta: model = MyModel exclude = [] field_1 = forms.CharField(label="field_1_label") field_2 = forms.CharField(label="field_2_label", widget=forms.Textarea(attrs={'class': 'width100 h4em'}),) field_3 = forms.CharField(label="field_3_label", widget=forms.TextInput(attrs={'class': 'width100'}),) field_4 = forms.ModelChoiceField(label='field_4_label', queryset=AnotherModel.objects.all().order_by("order") )class MyForm_Extended_1(MyForm): field_1 = Noneclass MyForm_Extended_2(MyForm): class Meta: model = MyModel exclude =[ 'field_1', ]
MyForm_Extended_1 set field_1 as None, (the column in db is updated as Null)
MyForm_Extended_2 ignore the field (ignore the column in db during the save)
So, for my purpose, I use the second method.