notifyPropertyChange

controllers.application.js

import Ember from 'ember';

const {
  computed,
  get,
  observer
} = Ember;

export default Ember.Controller.extend({
  appName: 'Ember Twiddle',
  
  someProperty: 3,
  anotherProperty: computed('thirdProperty', function() {
    return this.get('someProperty');
  }),
  
  _somePropertyDidChange: observer('thirdProperty', function() {
    console.log(`someProperty is now ${get(this, 'someProperty')}`);
  }),
  
  actions: {
		notify(property) {
      this.notifyPropertyChange(property);
    }
  }
});

templates.application.hbs

{{input value=someProperty}}

{{anotherProperty}}

<button {{action 'notify' 'thirdProperty'}}>
Notify!
</button>

twiddle.json

{
  "version": "0.8.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.5.1",
    "ember-data": "2.5.2",
    "ember-template-compiler": "2.5.1"
  }
}