diff options
| -rw-r--r-- | django/forms/forms.py | 4 | ||||
| -rw-r--r-- | docs/ref/forms/api.txt | 18 | ||||
| -rw-r--r-- | docs/releases/1.7.txt | 4 | ||||
| -rw-r--r-- | docs/topics/forms/modelforms.txt | 6 | ||||
| -rw-r--r-- | tests/model_forms/tests.py | 20 |
5 files changed, 39 insertions, 13 deletions
diff --git a/django/forms/forms.py b/django/forms/forms.py index f868165977..b5cf17f4eb 100644 --- a/django/forms/forms.py +++ b/django/forms/forms.py @@ -92,8 +92,8 @@ class DeclarativeFieldsMetaclass(MediaDefiningClass): declared_fields.update(base.declared_fields) # Field shadowing. - for attr in base.__dict__.keys(): - if attr in declared_fields: + for attr, value in base.__dict__.items(): + if value is None and attr in declared_fields: declared_fields.pop(attr) new_class.base_fields = declared_fields diff --git a/docs/ref/forms/api.txt b/docs/ref/forms/api.txt index 950bd3a088..10e85b4019 100644 --- a/docs/ref/forms/api.txt +++ b/docs/ref/forms/api.txt @@ -982,10 +982,20 @@ classes:: .. versionadded:: 1.7 -* 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 use ``None`` to make it explicit that a field is being - nullified. +* It's possible to declaratively remove a ``Field`` inherited from a parent + class by setting the name to be ``None`` on the subclass. For example:: + + >>> from django import forms + + >>> class ParentForm(forms.Form): + ... name = forms.CharField() + ... age = forms.IntegerField() + + >>> class ChildForm(ParentForm): + ... name = None + + >>> ChildForm().fields.keys() + ... ['age'] .. _form-prefix: diff --git a/docs/releases/1.7.txt b/docs/releases/1.7.txt index a8e600a04b..0b43b97d73 100644 --- a/docs/releases/1.7.txt +++ b/docs/releases/1.7.txt @@ -544,8 +544,8 @@ Forms inheriting from both ``Form`` and ``ModelForm`` simultaneously have been removed as long as ``ModelForm`` appears first in the MRO. -* It's now possible to opt-out from a ``Form`` field declared in a parent class - by shadowing it with a non-``Field`` value. +* It's now possible to remove a field from a ``Form`` when subclassing by + setting the name to ``None``. * The new :meth:`~django.forms.Form.add_error()` method allows adding errors to specific form fields. diff --git a/docs/topics/forms/modelforms.txt b/docs/topics/forms/modelforms.txt index e96345f155..4ac4dcea90 100644 --- a/docs/topics/forms/modelforms.txt +++ b/docs/topics/forms/modelforms.txt @@ -666,10 +666,8 @@ There are a couple of things to note, however. .. versionadded:: 1.7 -* 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 use ``None`` to make it explicit that a field is being - nullified. +* It's possible to declaratively remove a ``Field`` inherited from a parent class by + setting the name to be ``None`` on the subclass. You can only use this technique to opt out from a field defined declaratively by a parent class; it won't prevent the ``ModelForm`` metaclass from generating diff --git a/tests/model_forms/tests.py b/tests/model_forms/tests.py index c3b4c339c0..de96246c6f 100644 --- a/tests/model_forms/tests.py +++ b/tests/model_forms/tests.py @@ -2227,7 +2227,7 @@ class ModelFormInheritanceTests(TestCase): self.assertEqual(list(ModelForm().fields.keys()), ['name', 'age']) - def test_field_shadowing(self): + def test_field_removal(self): class ModelForm(forms.ModelForm): class Meta: model = Writer @@ -2250,6 +2250,24 @@ class ModelFormInheritanceTests(TestCase): self.assertEqual(list(type(str('NewForm'), (ModelForm, Form, Mixin), {})().fields.keys()), ['name', 'age']) self.assertEqual(list(type(str('NewForm'), (ModelForm, Form), {'age': None})().fields.keys()), ['name']) + def test_field_removal_name_clashes(self): + """Regression test for https://code.djangoproject.com/ticket/22510.""" + + class MyForm(forms.ModelForm): + media = forms.CharField() + + class Meta: + model = Writer + fields = '__all__' + + class SubForm(MyForm): + media = None + + self.assertIn('media', MyForm().fields) + self.assertNotIn('media', SubForm().fields) + self.assertTrue(hasattr(MyForm, 'media')) + self.assertTrue(hasattr(SubForm, 'media')) + class StumpJokeForm(forms.ModelForm): class Meta: |