New Twiddle

router.js

import Ember from 'ember';
import config from './config/environment';

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

Router.map(function() {
  this.route('outside', { path: '/' }, function() {
    this.route('inside', { path: '/' });
  });
});

export default Router;

routes.outside.inside.js

import Ember from 'ember';
let Promise = Ember.RSVP.Promise;

export default Ember.Route.extend({
  model() {
    return new Promise(function(resolve) {
      setTimeout(resolve, 1000);
    });
  },
  actions: {
    again() {
      this.refresh();
    }
  }
});

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

templates.application.hbs

{{outlet}}

templates.outside.hbs

<h1>This outer route renders instantly.</h1>

{{outlet}}

templates.outside.inside.hbs

<h2>This inside route simulates loading based on slower remote data.</h2>

<button {{action "again"}}>Show it again</button>

templates.outside.loading.hbs

<style type="text/css">
.spinner {
  margin: auto;
  width: 60px;
  height: 60px;
  position: relative;
}

.container1 > div, .container2 > div, .container3 > div {
  width: 12px;
  height: 12px;
  background-color: red;

  border-radius: 100%;
  position: absolute;
  -webkit-animation: bouncedelay 1.2s infinite ease-in-out;
  animation: bouncedelay 1.2s infinite ease-in-out;
  /* Prevent first frame from flickering when animation starts */
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
}

.spinner .spinner-container {
  position: absolute;
  width: 100%;
  height: 100%;
}

.container2 {
  -webkit-transform: rotateZ(45deg);
  transform: rotateZ(45deg);
}

.container3 {
  -webkit-transform: rotateZ(90deg);
  transform: rotateZ(90deg);
}

.circle1 { top: 0; left: 0; }
.circle2 { top: 0; right: 0; }
.circle3 { right: 0; bottom: 0; }
.circle4 { left: 0; bottom: 0; }

.container2 .circle1 {
  -webkit-animation-delay: -1.1s;
  animation-delay: -1.1s;
}

.container3 .circle1 {
  -webkit-animation-delay: -1.0s;
  animation-delay: -1.0s;
}

.container1 .circle2 {
  -webkit-animation-delay: -0.9s;
  animation-delay: -0.9s;
}

.container2 .circle2 {
  -webkit-animation-delay: -0.8s;
  animation-delay: -0.8s;
}

.container3 .circle2 {
  -webkit-animation-delay: -0.7s;
  animation-delay: -0.7s;
}

.container1 .circle3 {
  -webkit-animation-delay: -0.6s;
  animation-delay: -0.6s;
}

.container2 .circle3 {
  -webkit-animation-delay: -0.5s;
  animation-delay: -0.5s;
}

.container3 .circle3 {
  -webkit-animation-delay: -0.4s;
  animation-delay: -0.4s;
}

.container1 .circle4 {
  -webkit-animation-delay: -0.3s;
  animation-delay: -0.3s;
}

.container2 .circle4 {
  -webkit-animation-delay: -0.2s;
  animation-delay: -0.2s;
}

.container3 .circle4 {
  -webkit-animation-delay: -0.1s;
  animation-delay: -0.1s;
}

@-webkit-keyframes bouncedelay {
  0%, 80%, 100% { -webkit-transform: scale(0.0) }
  40% { -webkit-transform: scale(1.0) }
}

@keyframes bouncedelay {
  0%, 80%, 100% {
    transform: scale(0.0);
    -webkit-transform: scale(0.0);
  } 40% {
    transform: scale(1.0);
    -webkit-transform: scale(1.0);
  }
}

</style>

<div class="spinner">
  <div class="spinner-container container1">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="spinner-container container2">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
  <div class="spinner-container container3">
    <div class="circle1"></div>
    <div class="circle2"></div>
    <div class="circle3"></div>
    <div class="circle4"></div>
  </div>
</div>

twiddle.json

{
  "version": "0.10.6",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.9.0",
    "ember-data": "2.9.0",
    "ember-template-compiler": "2.9.0",
    "ember-testing": "2.9.0"
  },
  "addons": {}
}