Fixed #14099 - BaseModelFormSet should use _should_delete_form

Thanks to kenth for the report and patch.

git-svn-id: http://code.djangoproject.com/svn/django/trunk@15612 bcc190cf-cafb-0310-a4f2-bffc1f526a37

tests/regressiontests/model_formsets_regress/tests.py

@@ -1,6 +1,7 @@
 from django import forms
+from django.forms.formsets import BaseFormSet, DELETION_FIELD_NAME
 from django.forms.util import ErrorDict, ErrorList
-from django.forms.models import modelform_factory, inlineformset_factory, modelformset_factory
+from django.forms.models import modelform_factory, inlineformset_factory, modelformset_factory, BaseModelFormSet
 from django.test import TestCase
 
 from models import User, UserSite, Restaurant, Manager, Network, Host
@@ -283,3 +284,124 @@ class FormfieldCallbackTests(TestCase):
         modelformset_factory(UserSite, form=UserSiteForm,
                              formfield_callback=callback)
         self.assertCallbackCalled(callback)
+
+
+class BaseCustomDeleteFormSet(BaseFormSet):
+    """
+    A formset mix-in that lets a form decide if it's to be deleted.
+    Works for BaseFormSets. Also works for ModelFormSets with #14099 fixed.
+
+    form.should_delete() is called. The formset delete field is also suppressed.
+    """
+    def add_fields(self, form, index):
+        super(BaseCustomDeleteFormSet, self).add_fields(form, index)
+        self.can_delete = True
+        if DELETION_FIELD_NAME in form.fields:
+            del form.fields[DELETION_FIELD_NAME]
+
+    def _should_delete_form(self, form):
+        return hasattr(form, 'should_delete') and form.should_delete()
+
+
+class FormfieldShouldDeleteFormTests(TestCase):
+    """
+    Regression for #14099: BaseModelFormSet should use ModelFormSet method _should_delete_form
+    """
+
+    class BaseCustomDeleteModelFormSet(BaseModelFormSet, BaseCustomDeleteFormSet):
+        """ Model FormSet with CustomDelete MixIn """
+
+    class CustomDeleteUserForm(forms.ModelForm):
+        """ A model form with a 'should_delete' method """
+        class Meta:
+            model = User
+
+        def should_delete(self):
+            """ delete form if odd PK """
+            return self.instance.id % 2 != 0
+
+    NormalFormset = modelformset_factory(User, form=CustomDeleteUserForm, can_delete=True)
+    DeleteFormset = modelformset_factory(User, form=CustomDeleteUserForm, formset=BaseCustomDeleteModelFormSet)
+
+    data = {
+            'form-TOTAL_FORMS': '4',
+            'form-INITIAL_FORMS': '0',
+            'form-MAX_NUM_FORMS': '4',
+            'form-0-username': 'John',
+            'form-0-serial': '1',
+            'form-1-username': 'Paul',
+            'form-1-serial': '2',
+            'form-2-username': 'George',
+            'form-2-serial': '3',
+            'form-3-username': 'Ringo',
+            'form-3-serial': '5',
+            }
+
+    bound_ids = {
+            'form-INITIAL_FORMS': '4',
+            'form-0-id': '1',
+            'form-1-id': '2',
+            'form-2-id': '3',
+            'form-3-id': '4',
+            }
+
+    delete_all_ids = {
+            'form-0-DELETE': '1',
+            'form-1-DELETE': '1',
+            'form-2-DELETE': '1',
+            'form-3-DELETE': '1',
+            }
+
+    def test_init_database(self):
+        """ Add test data to database via formset """
+        formset = self.NormalFormset(self.data)
+        self.assertTrue(formset.is_valid())
+        self.assertEqual(len(formset.save()), 4)
+
+    def test_no_delete(self):
+        """ Verify base formset doesn't modify database """
+        # reload database
+        self.test_init_database()
+
+        # pass standard data dict & see none updated
+        data = dict(self.data)
+        data.update(self.bound_ids)
+        formset = self.NormalFormset(data, queryset=User.objects.all())
+        self.assertTrue(formset.is_valid())
+        self.assertEqual(len(formset.save()), 0)
+        self.assertEqual(len(User.objects.all()), 4)
+
+    def test_all_delete(self):
+        """ Verify base formset honors DELETE field """
+        # reload database
+        self.test_init_database()
+
+        # create data dict with all fields marked for deletion
+        data = dict(self.data)
+        data.update(self.bound_ids)
+        data.update(self.delete_all_ids)
+        formset = self.NormalFormset(data, queryset=User.objects.all())
+        self.assertTrue(formset.is_valid())
+        self.assertEqual(len(formset.save()), 0)
+        self.assertEqual(len(User.objects.all()), 0)
+
+    def test_custom_delete(self):
+        """ Verify DeleteFormset ignores DELETE field and uses form method """
+        # reload database
+        self.test_init_database()
+
+        # Create formset with custom Delete function
+        # create data dict with all fields marked for deletion
+        data = dict(self.data)
+        data.update(self.bound_ids)
+        data.update(self.delete_all_ids)
+        formset = self.DeleteFormset(data, queryset=User.objects.all())
+
+        # verify two were deleted
+        self.assertTrue(formset.is_valid())
+        self.assertEqual(len(formset.save()), 0)
+        self.assertEqual(len(User.objects.all()), 2)
+
+        # verify no "odd" PKs left
+        odd_ids = [user.id for user in User.objects.all() if user.id % 2]
+        self.assertEqual(len(odd_ids), 0)