New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  data: Ember.computed(() => [
    {
      label: '1.0',
      children: [{ label: '1.1' }, { label: '1.2', children: [ {label: '1.2.1' }] }],
    },
    {
      label: '2.0',
      children: [{ label: '2.1' }],
    }
  ]),
});

my-component.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  tagName: 'ul',
});

my-component.template.hbs

  {{#each data as |row|}}
	  <li>
    	{{row.label}}
      {{#if row.children}}
        {{my-component data=row.children}}
      {{/if}}
     </li>
  {{/each}}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-component data=data}}
<br>
<br>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": true,
    "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": {
  }
}