16980 Define Property

controllers.application.js

import { computed, defineProperty } from '@ember/object';
import { later } from '@ember/runloop';

export default Ember.Controller.extend({
  init() {
    later(() => {
      defineProperty(this, 'delayedProperty', computed(() => 'foo'));
      this.notifyPropertyChange('delayedProperty');
    }, 2000);
  },
  delayedProperty: 'bar',
  textToShow: computed('delayedProperty', function() {
    return this.get('delayedProperty');
  })  
});

templates.application.hbs

<h1>Should change from bar to foo after 2sec ->{{textToShow}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.15.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.2.2",
    "ember-template-compiler": "3.2.2",
    "ember-testing": "3.2.2"
  },
  "addons": {
    "ember-data": "3.2.0"
  }
}