Aurelia code quality - part 6

app.js

import {EventAggregator} from 'aurelia-event-aggregator';
import {inject} from 'aurelia-framework';

@inject(EventAggregator)
export class App{
  
  constructor(eventAggregator){
    this.eventAggregator = eventAggregator;
  }

  attached(){
    this.greetingAddedSubscription = 
    this.eventAggregator.subscribe(`greeting-added`, greeting => {
       alert(greeting);
    });
  }
  
  detached(){
    //clean up the subscription when app component is removed from the DOM
    this.greetingAddedSubscription.dispose();
  }
}