https://stackoverflow.com/questions/44246042/emberjs-call-parent-class-function-from-child-class-init-method/44246092

controllers.application.js

import Ember from 'ember';
var MyBaseClass = Ember.Object.extend({
  getData:function() {
    return 'test';
  }
});
var MyChildClass = MyBaseClass.extend({
  sampleData:'',
  init:function(){
    Ember.set(this, 'sampleData', this.getData());
  }
})
export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  init(){
    this._super(...arguments);
    this.set('childObj',MyChildClass.create());
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
{{childObj.sampleData}}
<br>
{{outlet}}
<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"
  }
}