Data Down, Actions Up example

components-my-counter.js

export default Ember.Component.extend({
  count: 0,
  
  actions: {
    incrementCount: function() {
      this.set('count', this.get('count') + 1);
      if(this.attrs['on-change']) {
        this.attrs['on-change'](this.get('count'));
      }
    }
  }
});

index.hbs

{{my-counter count=controller.count on-change=(action "handleCounterChange")}}

index.js

// controllers/index.js
export default Ember.Controller.extend({
  // Count prop bound to my-counter component.
  count: 1,
  
  actions: {
    handleCounterChange(newCount) {
      this.set('count', newCount);
    }
  }
});

templates-my-counter.hbs

<p>Current +1s: {{count}}</p>
<button {{action "incrementCount"}}>+1 Me</button>