Fixed #10284 -- ModelFormSet.save(commit=False) no longer deletes objects

Thanks laureline.guerin@ and Wedg.

django/forms/models.py

@@ -717,7 +717,8 @@ class BaseModelFormSet(BaseFormSet):
             obj = self._existing_object(pk_value)
             if form in forms_to_delete:
                 self.deleted_objects.append(obj)
-                obj.delete()
+                if commit:
+                    obj.delete()
                 continue
             if form.has_changed():
                 self.changed_objects.append((obj, form.changed_data))

docs/releases/1.7.txt

@@ -94,6 +94,11 @@ Miscellaneous
   have a custom :class:`~django.core.files.uploadhandler.FileUploadHandler`
   that implements ``new_file()``, be sure it accepts this new parameter.
 
+* :class:`ModelFormSet<django.forms.models.BaseModelFormSet>`'s no longer
+  delete instances when ``save(commit=False)`` is called. See
+  :attr:`~django.forms.formsets.BaseFormSet.can_delete` for instructions on how
+  to manually delete objects from deleted forms.
+
 Features deprecated in 1.7
 ==========================
 

docs/topics/forms/formsets.txt

@@ -3,7 +3,10 @@
 Formsets
 ========
 
-.. class:: django.forms.formsets.BaseFormSet
+.. module:: django.forms.formsets
+    :synopsis: An abstraction for working with multiple forms on the same page.
+
+.. class:: BaseFormSet
 
 A formset is a layer of abstraction to work with multiple forms on the same
 page. It can be best compared to a data grid. Let's say you have the following
@@ -164,9 +167,7 @@ As we can see, ``formset.errors`` is a list whose entries correspond to the
 forms in the formset. Validation was performed for each of the two forms, and
 the expected error message appears for the second item.
 
-.. currentmodule:: django.forms.formsets.BaseFormSet
+.. method:: BaseFormSet.total_error_count(self)
-
-.. method:: total_error_count(self)
 
 .. versionadded:: 1.6
 
@@ -353,6 +354,8 @@ formsets and deletion of forms from a formset.
 ``can_order``
 ~~~~~~~~~~~~~
 
+.. attribute:: BaseFormSet.can_order
+
 Default: ``False``
 
 Lets you create a formset with the ability to order::
@@ -411,6 +414,8 @@ happen when the user changes these values::
 ``can_delete``
 ~~~~~~~~~~~~~~
 
+.. attribute:: BaseFormSet.can_delete
+
 Default: ``False``
 
 Lets you create a formset with the ability to select forms for deletion::
@@ -463,10 +468,23 @@ delete fields you can access them with ``deleted_forms``::
 
 If you are using a :class:`ModelFormSet<django.forms.models.BaseModelFormSet>`,
 model instances for deleted forms will be deleted when you call
-``formset.save()``. On the other hand, if you are using a plain ``FormSet``,
+``formset.save()``.
-it's up to you to handle ``formset.deleted_forms``, perhaps in your formset's
+
-``save()`` method, as there's no general notion of what it means to delete a
+.. versionchanged:: 1.7
-form.
+
+    If you call ``formset.save(commit=False)``, objects will not be deleted
+    automatically.  You'll need to call ``delete()`` on each of the
+    :attr:`formset.deleted_objects
+    <django.forms.models.BaseModelFormSet.deleted_objects>` to actually delete
+    them::
+
+        >>> instances = formset.save(commit=False)
+        >>> for obj in formset.deleted_objects:
+        ...     obj.delete()
+
+On the other hand, if you are using a plain ``FormSet``, it's up to you to
+handle ``formset.deleted_forms``, perhaps in your formset's ``save()`` method,
+as there's no general notion of what it means to delete a form.
 
 Adding additional fields to a formset
 -------------------------------------

docs/topics/forms/modelforms.txt

@@ -825,6 +825,13 @@ to the database. If your formset contains a ``ManyToManyField``, you'll also
 need to call ``formset.save_m2m()`` to ensure the many-to-many relationships
 are saved properly.
 
+After calling ``save()``, your model formset will have three new attributes
+containing the formset's changes:
+
+.. attribute:: models.BaseModelFormSet.changed_objects
+.. attribute:: models.BaseModelFormSet.deleted_objects
+.. attribute:: models.BaseModelFormSet.new_objects
+
 .. _model-formsets-max-num:
 
 Limiting the number of editable objects

tests/model_formsets/tests.py

@@ -32,6 +32,9 @@ class DeletionTests(TestCase):
             'form-0-DELETE': 'on',
         }
         formset = PoetFormSet(data, queryset=Poet.objects.all())
+        formset.save(commit=False)
+        self.assertEqual(Poet.objects.count(), 1)
+
         formset.save()
         self.assertTrue(formset.is_valid())
         self.assertEqual(Poet.objects.count(), 0)