New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  checkboxes: Ember.computed(function() {
    return Array.from({length: 4}, (x, i) => {
      return {
        index: i,
        checked: i >= 2
      };
    });
  }),
  checkboxesAsJson: Ember.computed('checkboxes.@each.checked', function() {
    return JSON.stringify(this.get('checkboxes'), null, 2);
  }),
  actions: {
    check(i) {
      console.log("HEY");
      const k = `checkboxes.${i}.checked`;
      this.set(k, !this.get(k));
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{#each checkboxes as |check|}}
	<div>
    <label>
      <input
      	type="checkbox"
        checked={{check.checked}}
        onclick={{action "check" check.index}}
      >
      Item {{check.index}}
    </label>
  </div>
{{/each}}

<pre>{{checkboxesAsJson}}</pre>

{{outlet}}

<br>
<br>

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.2",
    "ember-data": "2.11.0",
    "ember-template-compiler": "2.10.2",
    "ember-testing": "2.10.2"
  },
  "addons": {}
}