New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
	value: Ember.computed('selection', {
     get(key) {
	    return this.get('selection.id') || '';
     },
		set(key, value) {
    return value;
    }
  })
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  selection: { id: Math.random()},
  value: ''
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
value - {{value}}
<br>
selection - {{selection.id}}
<hr>
{{my-component value=value selection=selection}}
{{outlet}}
<br>
<br>

templates.components.my-component.hbs

value - {{value}}
<br>
selection - {{selection.id}}
{{yield}}

twiddle.json

{
  "version": "0.7.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "release",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "release"
  }
}