New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  selected: false,
  message: '',
  
  computed: Ember.computed('selected', function() {
    this.append('computed');
    return this.get('selected');
	}),

	observer1: Ember.observer('computed', function() {
    this.append('observer1');
	}),

	observer2: Ember.observer('selected', function() {
    this.append('observer2');
  }),
  
  append: function(message) {
    this.set('message', this.get('message') + "\n" + message);
  },
  
  actions: {
    click: function() {
      this.toggleProperty('selected');
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<button {{action "click"}}>Click me</button>
{{computed}}
Log:
<pre>{{message}}</pre>
<br>
<br>

twiddle.json

{
  "version": "0.11.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.11.0",
    "ember-data": "2.11.0",
    "ember-template-compiler": "2.11.0",
    "ember-testing": "2.11.0"
  },
  "addons": {}
}