myTwiddle

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  a: [1,2,3],
  b: [4,5,6],
  c: false,
  
  actions: {
    toggleLabels() {
      this.toggleProperty('c');
    }
  }
});

application.template.hbs

<h1>Parent</h1>
<div {{action 'toggleLabels'}}>
  <span class="button">Toggle Labels</span>
</div>
<br>
<br>
{{my-comp a=a b=b c=c}}
<br>
<br>

my-comp.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  a: null,
  b: null,
  _b: null,
  __b: Ember.computed('b', {
  	get() {
			return this.get('__b');
		},
  	set(key, value) {
			console.log('processing "b"');
			this.set('__b', value);
			return value;
		}
  }),
  
  didUpdateAttrs(attrs) {
  	console.log(attrs.newAttrs, attrs.oldAttrs)
	},
  
  didInsertElement() {
    console.log(this.__b);
  }
});

my-comp.template.hbs

<h2>Child</h2>

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.button {
  border-radius: 2px;
  border: 1px solid black;
  background-color: grey;
  color: white;
  cursor: pointer;
  padding: 4px;
}

twiddle.json

{
  "version": "0.5.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}