Ticket #8620: 8620_3.diff

docs/topics/forms/modelforms.txt

@@ -516 +516 @@
 This adds the extra method from the ``EnhancedArticleForm`` and modifies
 the original ``ArticleForm.Meta`` to remove one field.
 
+If you need to remove a field from the child form that was explicitly defined in 
+a parent form, you can include it in the ``Meta.exclude`` list.
+
+An example::
+
+    class ArticleForm(ModelForm):
+        notes = TextField()
+        
+        class Meta:
+            model = Article
+
+    class EnhancedArticleForm(ArticleForm):
+        class Meta(ArticleForm.Meta):
+            exclude = ('notes',)
+
+The ``EnhancedArticleForm`` will not include the field ``notes``, though it was 
+explicitly declared on ``ArticleForm``.
+
 There are a couple of things to note, however.
 
 * Normal Python name resolution rules apply. If you have multiple base

django/forms/models.py

@@ -215 +215 @@
                 raise FieldError(message)
             # Override default model fields with any custom declared ones
             # (plus, include all the other declared fields).
+            # Leave out custom declared fields mentioned in exclude
+            if opts.exclude:
+                [declared_fields.pop(f) for f in declared_fields.keys() if f in opts.exclude]
             fields.update(declared_fields)
         else:
             fields = declared_fields

tests/regressiontests/forms/tests/models.py

@@ -5 +5 @@
 
 from django.core.files.uploadedfile import SimpleUploadedFile
 from django.db import models
-from django.forms import Form, ModelForm, FileField, ModelChoiceField
+from django.forms import Form, ModelForm, FileField, ModelChoiceField, CharField
 from django.forms.models import ModelFormMetaclass
 from django.test import TestCase
 
@@ -160 +160 @@
 
         f = ExcludingForm({'name': u'Hello', 'value': 99, 'def_date': datetime.date(1999, 3, 2)})
         self.assertTrue(f.is_valid())
-        self.assertEqual(f.cleaned_data['name'], u'Hello')
+        self.assertNotIn('name', f.cleaned_data)
         obj = f.save()
         self.assertEqual(obj.name, u'class default value')
         self.assertEqual(obj.value, 99)
@@ -196 +196 @@
             model=A
 
         self.assertTrue(issubclass(ModelFormMetaclass('Form', (ModelForm,), {'Meta': Meta}), ModelForm))
+
+
+class TestTicket8620(TestCase):
+    '''Allow exclusion of not only model fields but also form fields (as
+    might be defined in a superclass) using the exclude Meta attribute.'''
+
+    class ParentForm(ModelForm):
+        extra_non_model_field = CharField()
+
+    class ChildForm(ParentForm):
+        class Meta:
+            model = Defaults  # any model is suitable for this test
+            exclude = ('extra_non_model_field',)
+
+    def test_extra_non_model_field_is_excluded(self):
+        form = TestTicket8620.ChildForm()
+        self.assertNotIn('extra_non_model_field', form.fields)
+