Reactive programming

controllers.application.js

import Ember from 'ember';

const Dose = Ember.Object.extend({
	hasReason: false,
  name: 'Dose',
});

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',

  hasDosesWithReason: Ember.computed.notEmpty('dosesWithReason').readOnly(),
  dosesWithReason: Ember.computed.filterBy('doses', 'hasReason', true).readOnly(),
  
  doses: Ember.A([
    Dose.create({ name: 'Dose-1', hasReason:true }),
    Dose.create({ name: 'Dose-2' }),
    Dose.create({ name: 'Dose-3' })
  ]),
  
  actions: {
   addDose() {
     this.get('doses').pushObject(Dose.create({name: 'New'}));
   },
    
   removeDose() {
     this.get('doses').removeAt(0);     
   },
  }
});

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
<ul>
{{#each doses as |dose|}}
	<li>
  	<span>{{dose.name}}</span>
  	<input type="checkbox" checked={{dose.hasReason}} onchange={{action (mut dose.hasReason) value='target.checked'}}/>
    {{dose.hasReason}}
  </li>
{{/each}}

{{#if hasDosesWithReason}}
<button>Save ME </button>
{{else}}
<button disabled>Save ME </button>
{{/if}}

</ul>
<br>
<br>

<button onclick={{action "addDose"}}>Add Dose</button>


<button onclick={{action "removeDose"}}>Remove Dose</button>

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"
  }
}