New Twiddle

components.search-input.js

import Ember from 'ember';

let { computed, TextField } = Ember;

export default TextField.extend({
  type: 'search',
  isExpanded: computed('value', function() {
    return Boolean(this.get('value'));
  }),
  classNameBindings: ['isExpanded:active']
});

controllers.application.js

import Ember from 'ember';

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

styles.app.css

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

input {
  width: 40px;
  height: 40px;
  border: 1px solid grey;
  font-size: 20px;
  transition: width 0.4s ease-in-out;
}

input.active {
	width: 100%;
}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{search-input value=searchTerm placeholder="..."}}
<br>
<br>

templates.components.search-input.hbs

{{yield}}

twiddle.json

{
  "version": "0.10.4",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.7.0",
    "ember-data": "2.7.0",
    "ember-template-compiler": "2.7.0"
  },
  "addons": {}
}