New Twiddle

components.auto-focus.js

import Component from 'ember-component';
import jQuery from 'jquery';
import { getParent } from '../utils/dom';
import { next } from 'ember-runloop';

export default Component.extend({
  tagName: '',

  didInsertElement() {
    this._super(...arguments);
    next(() => {
      jQuery(getParent(this)).find('[contenteditable=true],:input').first().focus();
    });
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({  
  focus: "one", 
  actions: {
    focusRandom() {
      var items = ["one", "two", "three", "four"];
     	var item = items[Math.floor(Math.random()*items.length)];
    	this.set("focus", item);
    }
  }
});

templates.application.hbs

<div>
  <input value="one"> 
  {{#if (eq focus "one")}}
    {{auto-focus}}
  {{/if}}
</div>

<div>
  <input value="two"> 
  {{#if (eq focus "two")}}
    {{auto-focus}}
  {{/if}}
</div>

<div>
  <input value="three"> 
  {{#if (eq focus "three")}}
    {{auto-focus}}
  {{/if}}
</div>

<div>
  <input value="four"> 
  {{#if (eq focus "four")}}
    {{auto-focus}}
  {{/if}}
</div>

<div>
	Focused {{focus}}
  <button onclick={{action "focusRandom"}}>Random</button>
</div>

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",
    "ember-truth-helpers": "1.3.0"
  }
}

utils.dom.js

import Ember from 'ember';

export function getParent(view) {
  if (view.get('tagName') === '') {
    // Beware: use of private API! :(
    if (Ember.ViewUtils && Ember.ViewUtils.getViewBounds) {
      return Ember.ViewUtils.getViewBounds(view).parentElement;
    } else {
      return view._renderNode.contextualElement;
    }
  } else {
    return view.get('element').parentNode;
  }
}