Create record with new hasMany relationship sends empty ids instead of attributes

[andruby]

With this Book model:

export default DS.Model.extend({
  title: DS.attr('string'),
  authors: DS.hasMany('author')
});

When creating a record with new authors.

var book = this.store.createRecord('book', {title: 'The Ember Way'});
book.get('authors').createRecord({name: 'Jack'});
book.save();

The author relationships are serialised as if they were already persisted. The relationship is serialised as a Resource Identifier Object.

{
  "data":{
    "attributes":{
      "title":"The Ember Way"
    },
    "relationships":{
      "authors":{
        "data":[
          {"type":"author", "id":null}
        ]
      }
    },
    "type":"book"
  }
}

From my understanding of JSONAPI, the unpersisted relationship should be serialised as a Resource Object with attributes.

{
  "data":{
    "attributes":{
      "title":"The Ember Way"
    },
    "relationships":{
      "authors":{
        "data":[
          {
            "attributes":{
              "name":"Jack"
            },
            "type":"author"
          }
        ]
      }
    },
    "type":"book"
  }
}

[wecc]

The author relationships are serialised as if they were already persisted

This looks like a bug to me. We wouldn't want to serialize new records before they have been saved. Not 100% sure what the correct path here would be.

From my understanding of JSONAPI, the unpersisted relationship should be serialised as a Resource Object with attributes.

Hm, I don't think "embedded" records in relationships are a thing in JSON API at all? Unsure though. Can you point me to the part of the spec that made you think this is the recommended behavior?

[andruby]

@wecc I think you are right. The JSONAPI spec does not explicitly support what I'm trying to do. It seems natural though, and need it to atomically create a new record with relationships. I'll go on the jsonapi discuss to see if they are looking at extending the spec for these kinds of requests. Thanks!

[andruby]

@wecc Ember-Data already supports serializing relationships through the EmbeddedRecordsMixin. Thanks to @lolmaus at json-api/json-api#795 (comment)

Adding the EmbeddedRecordsMixin was as easy as creating a custom serializer for Book from my example:

import DS from 'ember-data'
import ApplicationSerializer from 'face/application/serializer'

export default ApplicationSerializer.extend(DS.EmbeddedRecordsMixin, {
  attrs: {
    author: { embedded: 'always' }
  }
})