How to make embedded hasMany relationships work with ember data

Question

I can't get embedded hasMany to work correctly with ember data.

I have something like this

App.Post = DS.Model.extend({
  comments: DS.hasMany('App.Comment')
});

App.Comment = DS.Model.extend({
  post: DS.hasMany('App.Post'),
  name: attr('string')
});

And my API returns the following for GET /post:

[
  {
   id: 1
   comments: [{name: 'test'}, {name: 'test2'}]
  },
  ...
]

I need to send this with POST /post:

[
  {
    comments: [{name: 'test'}, {name: 'test2'}]
  },
  ...
]

I want to work with Ember models and have them make the appropriate requests:

var post = App.store.createRecord(App.Post, hash_post_without_comments);
post.get('comments').createRecord(hash_comment);

App.store.commit(); // This should call the POST api 

and

var posts = App.store.find(App.Post); // This should call the GET api 

When I try something like post: DS.hasMany('App.Post', {embedded: true}), the GET is working but the POST is trying to make a POST for the two records not only the parent one.

EDIT : My Real use case

1- I've just built ember data from master

2- My adapter: RESTAdapter

3- The serializer: JSONSerializer

4- I added

App.MyAdapter.map('App.Join', {
    columns: { embedded: 'always' }
});

5- My Models are:

App.Join = DS.Model.extend({
    rowCount: DS.attr('number'),
    columns: DS.hasMany('App.JoinColumn'),
});

App.JoinColumn = DS.Model.extend({
    join: DS.belongsTo('App.Join')
});

6- When:

var a = App.Join.find(1);
a.get('columns').createRecord({});
App.store.commit();

a POST for joincolumn is sent and the parent is not dirty

What am i missing?

Answer 1

On master, the correct API is:

App.Adapter.map('App.Post', {
  comments: { embedded: 'always' }
});

The two possible values of embedded are:

• load: The child records are embedded when loading, but should be saved as standalone records. In order for this to work, the child records must have an ID.
• always: The child records are embedded when loading, and are saved embedded in the same record. This, of course, affects the dirtiness of the records (if the child record changes, the adapter will mark the parent record as dirty).

If you don't have a custom adapter, you can call map directly on DS.RESTAdapter:

DS.RESTAdapter.map('App.Post', {
  comments: { embedded: 'always' }
});