newforms: Implemented apply_changes() method for form_for_instance Forms

git-svn-id: http://code.djangoproject.com/svn/django/trunk@4253 bcc190cf-cafb-0310-a4f2-bffc1f526a37

django/newforms/models.py

@@ -20,6 +20,22 @@ def create(self, save=True):
         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.
@@ -45,12 +61,13 @@ def form_for_instance(instance, form=BaseForm):
     opts = model._meta
     field_list = []
     for f in opts.fields + opts.many_to_many:
-        current_value = getattr(instance, f.attname)
+        current_value = f.value_from_object(instance)
         formfield = f.formfield(initial=current_value)
         if formfield:
             field_list.append((f.name, formfield))
     fields = SortedDictFromList(field_list)
-    return type(opts.object_name + 'InstanceForm', (form,), {'fields': fields, '_model': model})
+    return type(opts.object_name + 'InstanceForm', (form,),
+        {'fields': fields, '_model': model, 'apply_changes': make_apply_changes(opts, instance)})
 
 def form_for_fields(field_list):
     "Returns a Form class for the given list of Django database field instances."