https://pixelfed.hylobatidae.org/sw.js

1const OFFLINE_VERSION = 1;
2const CACHE_NAME = "offline";
3const OFFLINE_URL = "/offline.html";
4
5self.addEventListener("install", (event) => {
6	event.waitUntil(
7		(async () => {
8			const cache = await caches.open(CACHE_NAME);
9			await cache.add(new Request(OFFLINE_URL, { cache: "reload" }));
10		})()
11	);
12	self.skipWaiting();
13});
14
15self.addEventListener("activate", (event) => {
16	event.waitUntil(
17		(async () => {
18			if ("navigationPreload" in self.registration) {
19				await self.registration.navigationPreload.enable();
20			}
21		})()
22	);
23	self.clients.claim();
24});
25
26self.addEventListener("fetch", (event) => {
27	if (event.request.mode === "navigate") {
28		event.respondWith(
29			(async () => {
30				try {
31					const preloadResponse = await event.preloadResponse;
32					if (preloadResponse) {
33						return preloadResponse;
34					}
35					const networkResponse = await fetch(event.request);
36					return networkResponse;
37				} catch (error) {
38					const cache = await caches.open(CACHE_NAME);
39					const cachedResponse = await cache.match(OFFLINE_URL);
40					return cachedResponse;
41				}
42			})()
43		);
44	}
45});