New Twiddle

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  actions: {
    fooBar() {
      this.set("foo", "bar");
    }
  },
  appName:'Ember Twiddle'
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{foo-bar foo=bar fooBar="fooBar"}}
app: {{foo}}
<br>
<br>

foo-bar.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  /*setFoo: Ember.on("didInitAttrs", function() {
    this.set("foo", "bar");
  }),*/
  
  setFoo2: Ember.on("didInitAttrs", function() {
    this.sendAction("fooBar");
  })
});

foo-bar.template.hbs

component: {{foo}}

twiddle.json

{
  "version": "0.4.16",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "canary",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "canary"
  }
}