Service Worker implementation informations

PWA on IOS

https://www.netguru.com/codestories/pwa-on-ios

Sample service worker

I am trying to implement a serviceworker with workbox. Everything is being cached online, but when I am going offline, I am getting "ERR_INTERNET_DISCONNECTED" error message. Also my precache and runtimecache is gone when I go offline.

When I write my own fetch method (without using the workbox routing methods), the serviceworker is working offline. And as far as I understood, fetching requests is handled by the handler in the routing methods, or am I wrong? So what am I missing to get my app working when in offline mode?

Here is my serviceworker source file (the precache files are being added during the build process):

importScripts(
  "https://storage.googleapis.com/workbox-cdn/releases/4.3.1/workbox-sw.js"
);

workbox.precaching.precacheAndRoute([]);

self.addEventListener("message", event => {
  if (event.data && event.data.type === "SKIP_WAITING") {
    self.skipWaiting();
  }
});

const bgSyncPlugin = new workbox.backgroundSync.Plugin("myQueueName", {
  maxRetentionTime: 24 * 60 // Retry for max of 24 Hours (specified in minutes)
});

workbox.routing.registerRoute(
  /\/api\/.*\/*.json/,
  new workbox.strategies.NetworkOnly({
    cacheName: "apiCallCache",
    plugins: [bgSyncPlugin]
  }),
  "POST"
);

workbox.routing.registerRoute(
  //match
  /\.(?:png|jpg|jpeg|svg|gif|css|js)$/,
  //handler
  new workbox.strategies.StaleWhileRevalidate({
    cacheName: "runtimeCache"
  })
);

use workbox locally

importScripts('/third_party/workbox/workbox-sw.js');

workbox.setConfig({
  modulePathPrefix: '/third_party/workbox/'
});