boolean attrs

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  on: false
});

templates.application.hbs

<label>
	<input type="checkbox" checked={{on}} onchange={{action (mut on) value='target.checked'}}>
	Toggle Attribute
</label>

<div data-attr={{on}}>Inspect me!</div>

twiddle.json

{
  "version": "0.10.7",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.0",
    "ember-data": "2.10.0",
    "ember-template-compiler": "2.10.0",
    "ember-testing": "2.10.0"
  },
  "addons": {}
}