+class AttributeForm(ModelForm):
+ def __init__(self, *args, **kwargs):
+ super(AttributeForm, self).__init__(*args, **kwargs)
+
+ # This is necessary because model forms store changes to self.instance in their clean method.
+ # Mutter mutter.
+ self._cached_value_ct = self.instance.value_content_type
+ self._cached_value = self.instance.value
+
+ if self.instance.value is not None:
+ value_field = self.instance.value.value_formfield()
+ if value_field:
+ self.fields['value'] = value_field
+ if hasattr(self.instance.value, 'content_type'):
+ self.fields['content_type'] = self.instance.value._meta.get_field('content_type').formfield(initial=getattr(self.instance.value.content_type, 'pk', None))
+
+ def save(self, *args, **kwargs):
+ # At this point, the cleaned_data has already been stored on self.instance.
+ if self.instance.value_content_type != self._cached_value_ct:
+ if self.instance.value is not None:
+ self._cached_value.delete()
+ if 'value' in self.cleaned_data:
+ del(self.cleaned_data['value'])
+
+ if self.instance.value_content_type is not None:
+ # Make a blank value of the new type! Run special code for content_type attributes.
+ if hasattr(self.instance.value_content_type.model_class(), 'content_type'):
+ if self._cached_value and hasattr(self._cached_value, 'content_type'):
+ new_ct = self._cached_value.content_type
+ else:
+ new_ct = None
+ new_value = self.instance.value_content_type.model_class().objects.create(content_type=new_ct)
+ else:
+ new_value = self.instance.value_content_type.model_class().objects.create()
+
+ new_value.apply_data(self.cleaned_data)
+ new_value.save()
+ self.instance.value = new_value
+ else:
+ # The value type is the same, but one of the fields has changed.
+ # Check to see if the changed value was the content type. We have to check the
+ # cleaned_data because self.instance.value.content_type was overridden.
+ if hasattr(self.instance.value, 'content_type') and 'content_type' in self.cleaned_data and 'value' in self.cleaned_data and (not hasattr(self._cached_value, 'content_type') or self._cached_value.content_type != self.cleaned_data['content_type']):
+ self.cleaned_data['value'] = None
+
+ self.instance.value.apply_data(self.cleaned_data)
+ self.instance.value.save()
+
+ super(AttributeForm, self).save(*args, **kwargs)
+ return self.instance
+
+ class Meta:
+ model = Attribute
+
+
+class AttributeInlineFormSet(BaseGenericInlineFormSet):
+ "Necessary to force the GenericInlineFormset to use the form's save method for new objects."
+ def save_new(self, form, commit):
+ setattr(form.instance, self.ct_field.get_attname(), ContentType.objects.get_for_model(self.instance).pk)
+ setattr(form.instance, self.ct_fk_field.get_attname(), self.instance.pk)
+ return form.save()
+
+