New Twiddle

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle'
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{parent-component}}
<br>
<br>

child-component.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  classNames:['child'],
  register:Ember.on('init',function(){
    this.get('parent').register(this);
  })
});

child-component.template.hbs

{{value}}

parent-component.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  classNames:['parent'],
  childValues:[1,2,3,4,5,6,7,8,9,0],
  childArray:Ember.A([]),
  register(child){
    this.get('childArray').pushObject(child);
  },
  lengths:Ember.computed('childArray',function(){
   return this.get('childArray').map(function(child){
    child.$().width(200)
    return child.$().innerWidth()
   })
  })
});

parent-component.template.hbs

{{#each childValues as |child|}}
   {{child-component value=child parent=this}}
{{/each}}


{{#each lengths as |width|}}
   {{width}}
{{/each}}

styles.app.css

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

.parent {
  border:1px solid green;
}

.child {
  display:inline-block;
  border:1px solid red;
  padding:10px;
  width:200px;
}

twiddle.json

{
  "version": "0.4.14",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.1.0/ember-template-compiler.js"
  }
}