New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

models.order.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  changeTracker: { auto: true },
  
  project: belongsTo()
});

models.project.js

import Model from "ember-data/model";
import attr from "ember-data/attr";
import { belongsTo, hasMany } from "ember-data/relationships";

export default Model.extend({
  changeTracker: { auto: true },
  
  orders: hasMany()
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
    let project = this.store.createRecord('project');
    let order = this.store.createRecord('order', {
      project
    });
    
    //order.saveChanges();
    //order.startTrack();
    
    return order.savedTrackerValue('project');
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
Saved Tracker Value: --&gt;{{model}}&lt;--
<br>
<br>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1",
    "ember-data-change-tracker": "0.5.6"
  }
}