[PWA] Check Online Status by using the NavigatorOnLine API

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
    })

[PWA] Check Online Status by using the NavigatorOnLine API

原文：https://www.cnblogs.com/Answer1215/p/9255725.html