Autofocus

controllers.application.js

import Ember from 'ember';

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

templates.application.hbs

<button onclick={{action toggleProperty "showForm"}}>
  {{if showForm "Hide" "Show"}} form
</button>

{{#if showForm}}
  <form>
    <label for="email">Name:</label>
    <input
      id="email"
      type="email"
      placeholder="alice@example.com"
      autofocus
    >
  </form>
{{/if}}

twiddle.json

{
  "version": "0.13.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.16.2",
    "ember-template-compiler": "2.16.2",
    "ember-testing": "2.16.2"
  },
  "addons": {
  }
}