sw.js

// Cache name has a timestamp because the browser re-caches the assets when the service worker file is modified
const staticCacheName = "nonogram-cache-" + "22-10-04-0000";
const assets = [
	'/nonogram/',
	'/nonogram/nonogram.css',
	'/nonogram/nonogram.js',
	'/nonogram/lib/Grid',
	'/nonogram/lib/Rng',
	'/repo/PinchToZoom',
	'/assets/ext/bootstrap.5.1.3.min.css',
];
const assets_extra = [
	'/nonogram/images/cross.svg',
	'/nonogram/images/cross-white.svg',
	'/nonogram/images/refresh.svg',
	'/nonogram/images/transparent.webp',
	'/nonogram/images/trash.svg',
	'/nonogram/images/lock.svg',
	'/nonogram/images/unlock.svg',

	'/nonogram/fonts/font-files/MPLUSRounded1c-Regular.20-3f.woff2',
	'/nonogram/fonts/font-files/MPLUSRounded1c-Regular.40-7f.woff2',
	'/nonogram/fonts/font-files/MPLUSRounded1c-Medium.20-3f.woff2',
	'/nonogram/fonts/font-files/MPLUSRounded1c-Medium.40-7f.woff2',

	'/nonogram/sounds/pop-39222.mp3',
	'/nonogram/sounds/notification-sound-7062.mp3',
	'/nonogram/sounds/stop-13692.mp3',
];

self.addEventListener('install', (evt) => {
	evt.waitUntil(
		(async () => {
			const cache = await caches.open(staticCacheName);
			cache.addAll(assets_extra).then();
			await cache.addAll(assets);
		})()
	);
});

self.addEventListener('activate', event => {
	event.waitUntil(
		(async () => {
			let cacheNames = await caches.keys();
			await Promise.all(cacheNames.map((cacheName) => {
				if (staticCacheName.indexOf(cacheName) === -1) return caches.delete(cacheName);
			}));
		})()
	);
});

self.addEventListener('fetch', function(event) {
	event.respondWith(
		(async () => {
			// try cache
			let response = await caches.match(event.request.url, {
				cacheName: staticCacheName,
				ignoreSearch: false
			});
			if (!!response) return response;

			// next try internet
			try {
				response = await fetch(event.request);
			} catch (e) {
				// if there's no internet, we'll ignore the query string
				return await caches.match(event.request.url, {
					cacheName: staticCacheName,
					ignoreSearch: true
				});
			}

			// add new file to cache (asynchronously)
			if (response.ok) {
				let clone = response.clone();
				caches.open(staticCacheName).then((cache) => cache.put(event.request, clone));
			}

			return response;
		})()
	);
});