New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
  items: [],
  newName: '',
  actions: {
    addItem () {
      console.log('action fired');
      console.log(this.get('newName'));
      this.get('items').pushObject({name: this.get('newName')});
			this.set('newName', '');
    }
  }
});

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
<h2> first component</h2>
{{my-component}}
<h2> second component</h2>
{{my-component}}
<br>
<br>

templates.components.my-component.hbs

<ul>
  {{#each items as |item|}}
    <li>{{item.name}}</li>
  {{/each}}
</ul>
Name: {{input type="text" value=newName}}
<button onclick={{action "addItem"}}>Add a new one</button>

twiddle.json

{
  "version": "0.11.0",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "1.13.13",
    "ember-data": "2.11.0",
    "ember-template-compiler": "1.13.13",
    "ember-testing": "1.13.13"
  },
  "addons": {}
}