Showcase Computed

controllers.application.js

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

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  init() {
    this._super(...arguments);
    this.set("sites", [1,2,3]);
    later(() => this.set("sites", [1,2,3,4]), 3000)
  },
  filteredSites: computed("sites", {
    get() {
    	console.log("computed!");
      return this.get("sites");
    }
  })
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<br>
<br>
{{#each filteredSites as |site index|}}
  {{index}}
{{/each}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}