https://www.slingo.com/service-worker.js?v=

1const SW = {
2	OFFLINE_PAGE: "/static/offline-dummy.html",
3	CACHE_NAME: null,
4	HOST: ['www.primeapi.com', 'qa.primeapi.com']
5};
6
7// Install stage sets up the index page (home page) in the cache and opens a new cache
8self.addEventListener("install", function (event) {
9	const url = new URL(location);
10	const v = url.searchParams.get('v');
11	const brandCode = url.searchParams.get('brand_code');
12
13	if (!v || !brandCode) {
14		console.error("Service worker missing params");
15		return;
16	}
17
18	SW.CACHE_NAME = `${brandCode}.${v}`;
19	SW.HOST.push(url.hostname);
20
21	event.waitUntil(
22		caches.open(SW.CACHE_NAME).then(function (cache) {
23			return cache.addAll(
24				[
25					SW.OFFLINE_PAGE
26				]
27			);
28		})
29	);
30});
31
32self.addEventListener('fetch', function (event) {
33	const { request } = event;
34	const url = new URL(event.request.url);
35	// Prevent Chrome Developer Tools error:
36	// Failed to execute 'fetch' on 'ServiceWorkerGlobalScope': 'only-if-cached' can be set only with 'same-origin' mode
37	//
38	// See also https://stackoverflow.com/a/49719964/1217468
39	if (request.cache === 'only-if-cached' && request.mode !== 'same-origin') {
40		return;
41	}
42
43	if (request.method !== 'GET' || SW.HOST.indexOf(url.hostname) === -1 || url.pathname.indexOf("/lp/") === -1 || url.pathname.startsWith('/son-api') || url.searchParams.get('no-cache') !== null) {
44		return;
45	}
46
47	event.respondWith(caches.open(SW.CACHE_NAME).then((cache) => {
48		// Respond with the image from the cache or from the network
49		return cache.match(event.request).then((cachedResponse) => {
50			return cachedResponse || fetch(event.request.url).then((fetchedResponse) => {
51				// Add the network response to the cache for future visits.
52				// Note: we need to make a copy of the response to save it in
53				// the cache and use the original as the request response.
54				cache.put(event.request, fetchedResponse.clone());
55
56				// Return the network response
57				return fetchedResponse;
58			});
59		});
60	}));
61});
62
63
64self.addEventListener('activate', event => {
65	// Clean up caches other than current.
66	event.waitUntil(async function () {
67		const cacheNames = await caches.keys();
68
69		await Promise.all(
70			cacheNames.filter((cacheName) => {
71				const deleteThisCache = cacheName !== SW.CACHE_NAME;
72				return deleteThisCache;
73			}).map(cacheName => caches.delete(cacheName))
74		);
75	}());
76});