New Twiddle

components.my-component.js

import Ember from 'ember';

export default Ember.Component.extend({
	watchMe: null,
  _watchMe: null,
  
  updates: Ember.computed(() => []),
  
  didReceiveAttrs() {
    const watchMe = this.get('watchMe');
    const _watchMe = this.get('_watchMe');
    
    this.set('_watchMe', watchMe);
    
    if (watchMe !== _watchMe) {
      this.logUpdate('watchMe', _watchMe, watchMe);
    } else {
      this.logUpdate('a different property');
    }
  },
	
  logUpdate(propertyName, from, to) {
  	this.get('updates').pushObject({
      propertyName,
      from: String(from),
      to: String(to)
    });
  }
});

controllers.application.js

import Ember from 'ember';

export default Ember.Controller.extend({
  watchMe: 'Hello',
  
  actions: {
    triggerGeneralUpdate(propertyName, newValue) {
      if (this.get(propertyName) === newValue) {
        this.set(propertyName, null);
        this.set(propertyName, newValue);
      } else {
        this.set(propertyName, newValue);
      }
    },
    triggerSpecificUpdate(propertyName, newValue) {
      if (this.get(propertyName) === newValue) {
        this.set(propertyName, null);
        Ember.run.schedule('render', this, this.set, propertyName, newValue);
      } else {
        this.set(propertyName, newValue);
      }
    }
  }
});

templates.application.hbs

{{input value=watchMe}}

<button onclick={{action "triggerGeneralUpdate" "watchMe" watchMe}}>
  Trigger General Update
</button>

<button onclick={{action "triggerSpecificUpdate" "watchMe" watchMe}}>
  Trigger Specific Update
</button>

{{my-component watchMe=watchMe}}

templates.components.my-component.hbs

<ul>
  {{#each updates as |update|}}
		<li>
      <strong>{{update.propertyName}}:</strong>
     	{{update.from}} -> {{update.to}}
     </li>
  {{/each}}
</ul>

twiddle.json

{
  "version": "0.10.5",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.8.0",
    "ember-data": "2.8.0",
    "ember-template-compiler": "2.8.0",
    "ember-testing": "2.8.0"
  },
  "addons": {}
}