New Twiddle

components.my-select.js

import Ember from 'ember';

export default Ember.Component.extend({
  actions: {
		onchange(value) {
      
    }
  }
});

controllers.application.js

import Ember from 'ember';

const { later } = Ember.run;

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  content: [
    { label: 'Option 1', value: '1' },
    { label: 'Option 2', value: '2' },
    { label: 'Option 3', value: '3' }
  ],
  
  actions: {
		onselect(value) {
      this.set('value', value);
      later(() => this.set('content', [
        { label: 'Option 1', value: '1' },
      	{ label: 'Option 2', value: '2' },
      	{ label: 'Option 3', value: '3' },
        { label: 'Option 4', value: '4' }
      ]), 2000);
    }
  }
});

helpers.eq.js

import Ember from 'ember';

export function eq(params/*, hash*/) {
  return params[0] === params[1];
}

export default Ember.Helper.helper(eq);

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{my-select content=content value=value onselect=(action "onselect")}}
<br>
<br>

templates.components.my-select.hbs

{{yield}}
<select oninput={{action onselect value="target.value"}}>
	{{#each content as |item|}}
  	<option value={{item.value}} selected={{eq item.value value}} data-selected={{eq item.value value}}>
    	{{item.label}}
		</option>
  {{/each}}
</select>

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"
  }
}