New Twiddle

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle',
  showCats: true,
  actions: {
    toggleCats() {
       this.toggleProperty('showCats')
    }
  }
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{#cat-list}}
  {{else}}
    no cats yet.
{{/cat-list}}
<button {{action "toggleCats"}}>Toggle Cats </button>
<br>
<br>

cat-list.component.js

import Ember from 'ember';

export default Ember.Component.extend({
  loadCats: null,
  localCats: ["Mike", "Dave", "Checkers"],
  fetchCats: Ember.computed(function() {
    let promise = new Ember.RSVP.Promise(function(resolve, reject) {
      console.log("promise")
      Ember.run.later(this, function() {
        resolve(["Fluffy", "Chuckles", "Steve"]);
      }, 2000);
    });
    return promise;
  })
})

cat-list.template.hbs

{{#promise-loader content=localCats as |cats|}}
  {{#each cats as |cat|}}
    {{cat}}
  {{else}}
   {{yield to="inverse"}}
  {{/each}}
{{else}}
  Loading...
{{/promise-loader}}

promise-loader.component.js

import Ember from 'ember';
import DS from 'ember-data';
let { PromiseObject } = DS;

export default Ember.Component.extend({
  content: null,
  promiseObject: Ember.computed('content', function() {
    return PromiseObject.create({promise: Ember.RSVP.cast(this.get('content'))});
  })
});

promise-loader.template.hbs

{{#unless promiseObject.isFulfilled}}
  {{yield to="inverse"}}
{{else}}
  {{yield promiseObject.content}}
{{/unless}}

twiddle.json

{
  "version": "0.5.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.2.0/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.2.0/ember-template-compiler.js"
  }
}