Capture backspace

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'input events demo',
  text: 'Hello, world',
  actions: {
    emberKeyDown(...args) {
      console.log('emberKeyDown action fired', args)
    },
    nativeKeyUp(event) {
      console.log('nativeKeyDown action fired', arguments);
      this.set('text', event.target.value);
    }
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
{{input
  key-down=(action "emberKeyDown")
  value=text
}}<br>
<input onKeyUp={{action "nativeKeyUp"}} value={{text}}>
<br>
text={{text}}

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2"
  }
}