Ember.js / Rails Posting Relationships to Rails

Question

Ok, I'm working on a simple Ember / Rails app, and I'm trying to post a hasMany association in a single HTTP request. For what it's worth, I'm using Rails for the API.

Ember: 1.4.0-beta.1+canary.011b67b8
Ember Data: 1.0.0-beta.5+canary.d9ce2a53
Handlebars: 1.1.1
jQuery: 1.10.2

Release Model

App.Release = DS.Model.extend
  name: DS.attr 'string'
  tracks: DS.hasMany 'track', {embedded: 'true'}

A "Release" has many "Tracks"

App.ReleasesNewRoute = Ember.Route.extend

  model: -> @store.createRecord 'release'

  afterModel: (release, transition)->
    release.get('tracks').addObject(@store.createRecord 'track',{
      name: 'Track 1'  
    }).pushObject(@store.createRecord 'track',{
      name: 'Track 2'  
    })

  setupController: (controller, model)->
    controller.set('content', model)

Releases Controller

App.ReleasesNewController = Ember.ObjectController.extend

  actions:{
    save: ->
      @content.save()
  }

How can I post the two tracks and one release at once? I'm planning to use accepts_nested_attributes_for :tracks in my Rails API... but I'll be happy if I can see the Tracks in my development console for a start.

possible duplicate of How to Add Child Record to Existing Parent Record? — Surendra Bobba

hhff hhff · Accepted Answer · 2014-01-02T09:00:19

I got this working like this:

App.ReleaseSerializer = DS.RESTSerializer.extend

  serializeHasMany: (record, json, relationship)->  
    key = relationship.key
    hasManyRecords = Ember.get(record, key)

    key = key+'_attributes'

    if hasManyRecords && relationship.options.embedded == 'true'
      json[key] = []
      hasManyRecords.forEach (item, index)->
        json[key].push(item.serialize())
    else
      @._super(record, json, relationship)

This works nicely with :accepts_nested_attributes_for in Rails. Rails is expecting a hash of track models nested under the release as tracks_attributes.

Couple gotchas:

Rails won't use the create action for the Child model, you'll have to put anything you wanna do to the children models in your Parent's create action.

Remember to whitelist your children's parameters for Rails 4. This looks like:

  def release_params
      params.require(:release).permit(:name, tracks_attributes: [:name])
  end

Ember.js / Rails Posting Relationships to Rails

2 Answers