New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
didReceiveAttrs() {
console.log('init');
this._super(...arguments);
this.set('currentIndex', this.get('commonIndex'));
this.inc();
},
didRender() {
console.log('render');
this._super(...arguments);
}
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
commonIndex: 0,
model: [1,2,3],
init() {
this._super(...arguments);
Ember.run.later(this, () => {
Ember.run.scheduleOnce('render', this,() => {
	this.set('model', [1,2]);
});
	console.log('done');
}, 3000);
},
actions:{
  inc(){ 
	this.incrementProperty('commonIndex');
  }
}
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
controller - index - {{commonIndex}}
<hr>

{{#each model as |item index|}}
{{my-component index=index commonIndex=commonIndex inc=(action 'inc')}}
{{/each}}
<br>
<br>

templates.components.my-component.hbs

{{currentIndex}}
{{yield}}

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "1.13.13",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "1.13.13"
  }
}