Optional Action with isDisabled

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  isDisabled: false,
  
  actions: {
    foo() {
      alert('Foo!');
    }
  }
});

helpers.optional.js

import Ember from 'ember';

export function optional([action]) {
  if (typeof action === 'function') {
    return action;
  }

  return (i) => i;
}

export default Ember.Helper.helper(optional);

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}

.button {
  display: inline-flex;
  align-items: center;
  height: 30px;
  padding: 0 15px;
  border: 1px solid gray;
  background: lightblue;
  cursor: pointer;
}

.disabled {
  background: lightgray;
  cursor: default;
}

templates.application.hbs

<div class="button" {{action toggleProperty "isDisabled"}}>
	{{#if isDisabled}}
		Enable Button
  {{else}}
  	Disable Button
  {{/if}}
</div>

<div class="{{if isDisabled "disabled"}} button" 
	{{action (optional (unless isDisabled (action "foo")))}}
>
	{{#if isDisabled}}
    Can't Click Me
  {{else}}
  	Click Me
  {{/if}}
</div>

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": {
    "ember-data": "2.16.3"
  }
}