New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  children: Ember.computed('model.children', function() {
    return this.get('model.children');
  })
});

models.person.js

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

export default Model.extend({
  name: attr('string'),
  children: hasMany('person', { async: true })
});

routes.application.js

import Ember from 'ember';

export default Ember.Route.extend({
  store: Ember.inject.service(),
  
  init() {
    this._super(...arguments);
    this.store = this.get('store');
    this.store.push({
      "data": {
        "id": 1,
        "type": "person",
        "attributes": {
          "name": "Jason Mitchell"
        },
        "relationships": {
            "children": {
                "data": [{
                    "id": "2",
                    "type": "person"
                }, {
                    "id": "3",
                    "type": "person"
                }, {
                    "id": "4",
                    "type": "person"
                }]
            }
        }
    	}
    });
  },
  model() {
    return this.store.findRecord('person', 1, {
      backgroundReload: false
    });
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
{{model.name}}
{{children.length}}

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"
  }
}