#nested attributes

[alessandrostone]

[pterofaur]

Ember and Rails and Nested Attributes

Nested attributes are really nice for reducing requests to your API. But EmberData doesn't handle them that well.

Problems and Solutions

Using accepts_nested_attributes_for expects the nested attributes to be under the key {model}_attributes but EmberData ActiveModelSerializer adapter doesn't want to do that so you will have to patch that. A variety of fixes are available on GitHub. Hopefully its pulled into EmberData eventually.

Make sure that you understand how you are serializing and deserializing your nested attributes. It may always be in records or it could be serialize: "records, deserialize: "ids". Look for Ember not recognizing keys in your payload.

When you are creating the nested attributes on the front end you will probably need some kind of proxy object.

You cannot rely solely on computed properties when saving and reloading models with nested properties. You must set _destroy on objects that have been persisted to the backend. However, you can't unload these records from the front end until you save the parent model. EmberData has no idea how to process the model that is returned. The destroyed models are not in the response payload but it assumes that the current ones you have on the client with _destroy tags are new instances. You must unload the orphaned records on your own. Just look for the _destroy: true flag on your child models associated with the parent after the promise resolves.