offline

// This is the “Offline page” service worker

importScripts(‘https://storage.googleapis.com/workbox-cdn/releases/5.1.2/workbox-sw.js’);

const CACHE = “pwabuilder-page”;

// TODO: replace the following with the correct offline fallback page i.e.: const offlineFallbackPage = “offline.html”;
const offlineFallbackPage = “ToDo-replace-this-name.html”;

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

self.addEventListener(‘install’, async (event) => {
event.waitUntil(
caches.open(CACHE)
.then((cache) => cache.add(offlineFallbackPage))
);
});

if (workbox.navigationPreload.isSupported()) {
workbox.navigationPreload.enable();
}

self.addEventListener(‘fetch’, (event) => {
if (event.request.mode === ‘navigate’) {
event.respondWith((async () => {
try {
const preloadResp = await event.preloadResponse;

    if (preloadResp) {
      return preloadResp;
    }

    const networkResp = await fetch(event.request);
    return networkResp;
  } catch (error) {

    const cache = await caches.open(CACHE);
    const cachedResp = await cache.match(offlineFallbackPage);
    return cachedResp;
  }
})());

}
});