Disabled Button Example

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  isDisabled: false,
  pureBoolean: Em.computed('isDisabled', function() {
  	return !this.get('isDisabled');
  }),
  
  actions: {
  	makeDisabled() {
      this.set('isDisabled', true);
    },
    
    
    // this resets example
    resetExample() {
      this.set('isDisabled', false);
    }
  }
});

templates.application.hbs

<h1>Disabled Button Example</h1>
<p>
  Use of truthy and falsey on a disabled button and also use of actual strict boolean on a disabled button (the reset button).
</p>

<button disabled={{if isDisabled true null}} {{action 'makeDisabled' on='click'}}>Click to disabled</button>

<button disabled={{pureBoolean}} {{action 'resetExample'}}>Reset Button</button>

{{outlet}}
<br>
<br>

twiddle.json

{
  "version": "0.9.3",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.4.5",
    "ember-data": "2.1.0",
    "ember-template-compiler": "2.4.5"
  }
}

This was a Twiddle done to demo an answer that was on StackOverflow. It is a workaround to returning null from a JavaScript function just to be able to make a disabled property function correctly in a template. It's a small thing but it separates concerns because now the JavaScript can return any falsey value and get the same effect as returning null to the property used to determine the buttons disabled state.