Even if you have your application fully cached, you couldn’t perform any external request without internet connection. That’s why in order to build an offline-capable application, you must know when it’s actually offline.
This lesson shows you how to use the NavigatorOnLine API and online/offline events in order to disable the functionality to send messages of the application.
this.online = navigator.onLine window.addEventListener('online', () => (this.online = true)) window.addEventListener('offline', () => { this.online = false })