Slack w/ @villander

components.checkbox-selection-item.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
    selectMe: function() {
      this.get('selection').pushObject(this.get('itemId'));
    }
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  selection: Ember.computed(() => []),
  colors: [
    'red',
    'green',
    'blue'
  ],
  
  _selectionDidChange: Ember.observer('selection.[]', function() {
	  console.log(this.get('selection'));
  })
});

templates.application.hbs

{{#each colors as |color|}}
	{{checkbox-selection-item
  	itemId=color
    selection=(mut selection)}}
{{/each}}

Selection:
<ul>
	{{#each selection as |color|}}
  	<li>{{color}}</li>
  {{/each}}
</ul>

templates.components.checkbox-selection-item.hbs

<button {{action 'selectMe'}}>
Select {{itemId}}
</button>

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}