New Twiddle

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle'
});

router.js

import EmberRouter from '@ember/routing/router';
import config from './config/environment';

const Router = EmberRouter.extend({
  location: 'none',
  rootURL: config.rootURL
});

Router.map(function() {
  this.route('parent-route', function() {
  	this.route('child-route');
  });
});

export default Router;

routes.parent-route.index.js

import Ember from 'ember';

export default Ember.Route.extend({
  model() {
  	return new Ember.RSVP.Promise(resolve => {
    	setTimeout(() => {
        resolve();
      }, 2000);
    });
  }
});

routes.parent-route.js

import Ember from 'ember';

export default Ember.Route.extend({
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<div>
{{#link-to 'parent-route'}}Parent Route{{/link-to}}
</div>
{{outlet}}
<br>
<br>

templates.parent-route.child-route.hbs

This is the child route template

templates.parent-route.hbs

This is the parent route template.
<ul>
<li>{{#link-to 'parent-route.child-route'}}Child Route{{/link-to}}</li>
<li>{{#link-to 'parent-route'}}Back to Parent{{/link-to}}</li>
</ul>
{{outlet}}

templates.parent-route.index.hbs

This is the parent-route.index template. 

templates.parent-route.loading.hbs

LOADING PLEASE WAIT...

twiddle.json

{
  "version": "0.14.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "2.18.2",
    "ember-template-compiler": "2.18.2",
    "ember-testing": "2.18.2"
  },
  "addons": {
    "ember-data": "2.18.2"
  }
}