Overwrite Computed Property

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  foo: 'foo',
  bar: 'bar',
  fooBar: Ember.computed('foo', 'bar', function() {
  	return this.get('foo') + this.get('bar');
  }),
  
  actions: {
		overwrite: function() {
    	this.set('fooBar', 'something else');  
  	}
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{input value=foo}}<br><br>
{{input value=bar}}
<br>
<br>
<button {{action "overwrite"}}>Overwrite computed property</button>
<p>
<code>foo</code> + <code>bar</code> = {{fooBar}}
</p>

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"
  }
}