New Twiddle

controllers.application.js

import Ember from 'ember';

const PERSON = 'person';
export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  init() {
    this._super(...arguments);
    this.person = {
      first: 0,
      last: 0
    };
  },
  
  fullname: Ember.computed(`${PERSON}.{first,last}`, function() {
    return this.get('person.first') + ' ' + this.get('person.last');
  }),
  
  actions: {
    updateFirst() {
      this.incrementProperty('person.first');
    },
    updateLast() {
      this.incrementProperty('person.last');
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{fullname}}<br />

<button {{action "updateFirst"}}>First</button>

<button {{action "updateLast"}}>Last</button>
<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"
  }
}