Vertical Thing

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  items: [],
    
  actions: {
		createItems () {
      for (let i = 0; i < 500; i++) {
        this.get('items').pushObject({
          number: i,
          name: `item ${i}`
        });
      }
		}
	}
});

styles.app.css

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

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<button {{action 'createItems'}}>createem</button>
<br>
{{#each items as | item |}}
	{{item.name}}
{{/each}}
<br>
{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.12.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.12.0",
    "ember-template-compiler": "2.12.0",
    "ember-testing": "2.12.0"
  },
  "addons": {
    "ember-data": "2.12.1",
    "@html-next/vertical-collection": "^1.0.0-beta.4"
  }
}