Ticket #3232: apply_changes.patch

django/newforms/forms.py

@@ -171 +171 @@
         """
         return self.clean_data
 
+    def apply_changes(self, instance=None, save=True):
+        if not instance:
+            instance = getattr(self, 'default_instance', None)
+            if not instance:
+                raise ValueError('An instance is required')
+        opts = instance._meta
+        if self.errors:
+            raise ValueError("The %s could not be changed because the data didn't validate." % opts.object_name)
+        # Generate a list of db fields for this instance.
+        db_fields = {}
+        for db_field in opts.fields + opts.many_to_many:
+            db_fields[db_field.attname] = db_field
+        # Save each field in the form which matches a db field.
+        for field in self.fields.keys():
+            db_field = db_fields.get(field)
+            setattr(instance, db_field.attname, self.clean_data[field])
+        if save:
+            instance.save()
+        return instance
+
 class Form(BaseForm):
     "A collection of Fields, plus their associated data."
     # This is a separate class from BaseForm in order to abstract the way

django/newforms/models.py

@@ -20 +20 @@
         obj.save()
     return obj
 
-def make_apply_changes(opts, instance):
-    "Returns the apply_changes() method for a form_for_instance Form."
-    from django.db import models
-    def apply_changes(self, save=True):
-        if self.errors:
-            raise ValueError("The %s could not be changed because the data didn't validate." % opts.object_name)
-        clean_data = self.clean_data
-        for f in opts.fields + opts.many_to_many:
-            if isinstance(f, models.AutoField):
-                continue
-            setattr(instance, f.attname, clean_data[f.name])
-        if save:
-            instance.save()
-        return instance
-    return apply_changes
-
 def form_for_model(model, form=BaseForm):
     """
     Returns a Form class for the given Django model class.
@@ -67 +51 @@
             field_list.append((f.name, formfield))
     fields = SortedDictFromList(field_list)
     return type(opts.object_name + 'InstanceForm', (form,),
-        {'fields': fields, '_model': model, 'apply_changes': make_apply_changes(opts, instance)})
+        {'fields': fields, '_model': model, 'default_instance': instance})
 
 def form_for_fields(field_list):
     "Returns a Form class for the given list of Django database field instances."

tests/modeltests/model_forms/models.py

@@ -12 +12 @@
 create(save=False), then you'll get the object without saving it.
 
 The function django.newforms.form_for_instance() takes a model instance and
-returns a Form that is tied to the instance. This form works just like any
-other Form, with one additional method: apply_changes(). The apply_changes()
-method updates the model instance. It saves the changes to the database if
-apply_changes(save=True), which is default. If you pass save=False, then you'll
-get the object without saving it.
+returns a Form that is tied to the instance.
+
+All forms now have the method apply_changes(instance), which can be used to
+update a model instance. Using form_for_instance() you do not need to pass
+an instance. It saves the changes to the database if apply_changes(save=True),
+which is default. If you pass save=False, then the unsaved instance object
+will be returned.
 """
 
 from django.db import models
@@ -153 +155 @@
 >>> f.say_hello()
 hello
 
-Use form_for_instance to create a Form from a model instance. There are two
-differences between this Form and one created via form_for_model. First, the
-object's current values are inserted as 'initial' data in each Field. Second,
-the Form gets an apply_changes() method instead of a create() method.
+Use form_for_instance to create a Form from a model instance. The difference
+between this Form and a normal form is that the object's current values are
+inserted as 'initial' data in each Field.
 >>> w = Writer.objects.get(name='Mike Royko')
 >>> RoykoForm = form_for_instance(w)
 >>> f = RoykoForm(auto_id=False)