Funky Computed Property

components.foo-bar.js

import Ember from 'ember';
const {Component, computed} = Ember;
export default Component.extend({
  mything: null,
  // thing value is also passed into the component
  // thing watches no keys, and is not consumed
  thing: computed({
    // the getter is ignored entirely
    set(k, v) {
      // do any amount of work here
      // could replace observer
    	console.log('do a mything');
      //affect other property on change
      this.set('mything', v);
      return v;
    }
  }),
  actions: {
    setmything(val) {
    	this.set('mything', val); 
    }
  }
});

controllers.application.js

import Ember from 'ember';
const {Controller, computed} = Ember;
export default Controller.extend({
  appName: 'Ember Twiddle',
  thing: computed({
    get() {
      // default
      console.log('thing get');
    	return 'nothing';
    },
    set(k, v) {
      // do something when the value changes
    	console.log('do a thing');
      return v;
    }
  }),
  actions: {
  	reset() {
      this.set('thing', 'nothing');
    },
    setThing(val) {
      console.log('setting thing');
      this.set('thing', val);
    }
  }
});

templates.application.hbs

<h1>Funky Computed Usage?</h1>
<br>
{{outlet}}
<div>
Application:<br>The thing is "{{thing}}"
</div>
<br>
<input value={{thing}} onchange={{action 'setThing' value="target.value"}}/>
<button onclick={{action 'setThing' thing}}>set</button>
<br>
<button onclick={{action 'reset'}}>reset</button>
<br>
<br>
<div>
Component:
{{foo-bar thing=thing}}
</div>
<div>
<p>The application controller has a computed property 'thing'. The 'thing' cp is passed into the foo-bar component.</p>
<p>The foo-bar component also has 'thing' as a computed property, setting the value of 'mything' in the setter of the computed property.</p>
<p>By using the setter of the 'thing' cp in the foo-bar component, we can call functions react to changes, similar to as if we'd set up an observer.</p>
<p>The 'thing' cp getter is not required, as it is completely ignored and never called/used.</p>
</div>

templates.components.foo-bar.hbs

{{#if mything}}
	<div>My thing is "{{mything}}"</div>
{{else}}
  <div>Sorry, no thing</div>
{{/if}}
<div>
My thing input:
<input value={{mything}} onchange={{action 'setmything' value="target.value"}}/>
</div>

twiddle.json

{
  "version": "0.7.2",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember.debug.js",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.4.3/ember-data.js",
    "ember-template-compiler": "https://cdnjs.cloudflare.com/ajax/libs/ember.js/2.4.4/ember-template-compiler.js"
  }
}