diff --git a/docs/topics/3.0-announcement.md b/docs/topics/3.0-announcement.md index 4a7815032..89817ea5d 100644 --- a/docs/topics/3.0-announcement.md +++ b/docs/topics/3.0-announcement.md @@ -116,11 +116,12 @@ This would now be split out into two separate methods. instance.language = validated_data.get('language', instance.language) instance.style = validated_data.get('style', instance.style) instance.save() + return instance def create(self, validated_data): return Snippet.objects.create(**validated_data) -Note that the `.create` method should return the newly created object instance. +Note that these methods should return the newly created object instance. #### Use `.validated_data` instead of `.object`. @@ -592,18 +593,27 @@ The `UniqueTogetherValidator` should be applied to a serializer, and takes a `qu The view logic for the default method handlers has been significantly simplified, due to the new serializers API. -#### Removal of pre/post save hooks. +#### Changes to pre/post save hooks. -The following method hooks no longer exist on the new, simplified, generic views: `pre_save`, `post_save`, `pre_delete`, `post_delete`. +The `pre_save` and `post_save` hooks no longer exist, but are replaced with `perform_create(self, serializer)` and `perform_update(self, serializer)`. -If you do need custom behavior, you might choose to instead override the `.save()` method on your serializer class. For example: +These method should save the object instance by calling `serializer.save()`, adding in any explicit additional arguments as required. They may also perform any custom pre-save or post-save behavior. - def save(self, *args, **kwargs): - instance = super(MySerializer).save(*args, **kwarg) +For example: + + def perform_create(self, serializer): + # Include the owner attribute directly, rather than from request data. + instance = serializer.save(owner=self.request.user) + # Perform a custom post-save action. send_email(instance.to_email, instance.message) - return instance -Alternatively write your view logic exlpicitly, or tie your pre/post save behavior into the model class or model manager. +The `pre_delete` and `post_delete` hooks no longer exist, and are replaced with `.perform_destroy(self, instance)`, which should delete the instance and perform any custom actions. + + def perform_destroy(self, instance): + # Perform a custom pre-delete action. + send_deletion_alert(user=instance.created_by, deleted=instance) + # Delete the object instance. + instance.delete() #### Removal of view attributes. diff --git a/rest_framework/mixins.py b/rest_framework/mixins.py index 03ebb0341..4c62debb0 100644 --- a/rest_framework/mixins.py +++ b/rest_framework/mixins.py @@ -20,11 +20,11 @@ class CreateModelMixin(object): def create(self, request, *args, **kwargs): serializer = self.get_serializer(data=request.data) serializer.is_valid(raise_exception=True) - self.create_valid(serializer) + self.perform_create(serializer) headers = self.get_success_headers(serializer.data) return Response(serializer.data, status=status.HTTP_201_CREATED, headers=headers) - def create_valid(self, serializer): + def perform_create(self, serializer): serializer.save() def get_success_headers(self, data): @@ -67,10 +67,10 @@ class UpdateModelMixin(object): instance = self.get_object() serializer = self.get_serializer(instance, data=request.data, partial=partial) serializer.is_valid(raise_exception=True) - self.update_valid(serializer) + self.preform_update(serializer) return Response(serializer.data) - def update_valid(self, serializer): + def preform_update(self, serializer): serializer.save() def partial_update(self, request, *args, **kwargs): @@ -84,9 +84,12 @@ class DestroyModelMixin(object): """ def destroy(self, request, *args, **kwargs): instance = self.get_object() - instance.delete() + self.perform_destroy(instance) return Response(status=status.HTTP_204_NO_CONTENT) + def perform_destroy(self, instance): + instance.delete() + # The AllowPUTAsCreateMixin was previously the default behaviour # for PUT requests. This has now been removed and must be *explicitly* diff --git a/rest_framework/serializers.py b/rest_framework/serializers.py index 3d868a9ee..e7cd50d67 100644 --- a/rest_framework/serializers.py +++ b/rest_framework/serializers.py @@ -83,7 +83,10 @@ class BaseSerializer(Field): ) if self.instance is not None: - self.update(self.instance, validated_data) + self.instance = self.update(self.instance, validated_data) + assert self.instance is not None, ( + '`update()` did not return an object instance.' + ) else: self.instance = self.create(validated_data) assert self.instance is not None, ( @@ -444,19 +447,19 @@ class ModelSerializer(Serializer): self.validators.extend(validators) self._kwargs['validators'] = validators - def create(self, attrs): + def create(self, validated_attrs): ModelClass = self.Meta.model - # Remove many-to-many relationships from attrs. + # Remove many-to-many relationships from validated_attrs. # They are not valid arguments to the default `.create()` method, # as they require that the instance has already been saved. info = model_meta.get_field_info(ModelClass) many_to_many = {} for field_name, relation_info in info.relations.items(): - if relation_info.to_many and (field_name in attrs): - many_to_many[field_name] = attrs.pop(field_name) + if relation_info.to_many and (field_name in validated_attrs): + many_to_many[field_name] = validated_attrs.pop(field_name) - instance = ModelClass.objects.create(**attrs) + instance = ModelClass.objects.create(**validated_attrs) # Save many-to-many relationships after the instance is created. if many_to_many: @@ -465,10 +468,11 @@ class ModelSerializer(Serializer): return instance - def update(self, obj, attrs): - for attr, value in attrs.items(): - setattr(obj, attr, value) - obj.save() + def update(self, instance, validated_attrs): + for attr, value in validated_attrs.items(): + setattr(instance, attr, value) + instance.save() + return instance def get_unique_together_validators(self): field_names = set([