ember-concurrency starter

controllers.application.js

import Ember from 'ember';
import { task, timeout } from 'ember-concurrency';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',

  myTask: task(function * () {
    let didConfirm = yield this.get('getConfirmation').perform("Are you sure?");
    if (didConfirm) {
      alert("woot");
    }
  }),

  confirmation: null,
  getConfirmation: task(function * (prompt) {
    try {
      let defer = Ember.RSVP.defer();
      this.set('confirmation', {
        resolve: defer.resolve,
        prompt
      });
      return yield defer.promise;
    } finally {
      this.set('confirmation', null);
    }
  })
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

<p>
  myTask is {{if myTask.isRunning 'running' 'NOT running'}}
</p>

<button onclick={{perform myTask}}>perform MyTask</button>

{{#if confirmation}}
  <h5>Confirm</h5>
  <p>
    {{confirmation.prompt}}
  </p>
  <button onclick={{action confirmation.resolve false}}>
    Cancel
  </button>
  <button onclick={{action confirmation.resolve true}}>
    Yes
  </button>
{{/if}}

twiddle.json

{
  "version": "0.10.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.6.0",
    "ember-data": "2.6.1",
    "ember-template-compiler": "2.6.0"
  },
  "addons": {
    "ember-concurrency": "latest"
  }
}