Skip to content

Instantly share code, notes, and snippets.

@100lvlmaster
Created June 27, 2021 21:01
Show Gist options
  • Save 100lvlmaster/8e966302b2e03404203e965424cb2bca to your computer and use it in GitHub Desktop.
Save 100lvlmaster/8e966302b2e03404203e965424cb2bca to your computer and use it in GitHub Desktop.
service-worker.ts
/// <reference lib="webworker" />
import { build, files, timestamp } from '$service-worker';
const worker = (self as unknown) as ServiceWorkerGlobalScope;
const FILES = `cache${timestamp}`;
// `build` is an array of all the files generated by the bundler,
// `files` is an array of everything in the `static` directory
const to_cache = build.concat(files);
const staticAssets = new Set(to_cache);
worker.addEventListener('install', (event) => {
event.waitUntil(
caches
.open(FILES)
.then((cache) => cache.addAll(to_cache))
.then(() => {
worker.skipWaiting();
})
);
});
worker.addEventListener('activate', (event) => {
event.waitUntil(
caches.keys().then(async (keys) => {
// delete old caches
for (const key of keys) {
if (key !== FILES) await caches.delete(key);
}
worker.clients.claim();
})
);
});
/**
* Fetch the asset from the network and store it in the cache.
* Fall back to the cache if the user is offline.
*/
async function fetchAndCache(request: Request) {
const cache = await caches.open(`offline${timestamp}`);
try {
const response = await fetch(request);
cache.put(request, response.clone());
return response;
} catch (err) {
const response = await cache.match(request);
if (response) return response;
throw err;
}
}
worker.addEventListener('fetch', (event) => {
if (event.request.method !== 'GET' || event.request.headers.has('range')) return;
const url = new URL(event.request.url);
// don't try to handle e.g. data: URIs
const isHttp = url.protocol.startsWith('http');
const isDevServerRequest =
url.hostname === self.location.hostname && url.port !== self.location.port;
const isStaticAsset = url.host === self.location.host && staticAssets.has(url.pathname);
const skipBecauseUncached = event.request.cache === 'only-if-cached' && !isStaticAsset;
if (isHttp && !isDevServerRequest && !skipBecauseUncached) {
event.respondWith(
(async () => {
// always serve static files and bundler-generated assets from cache.
// if your application has other URLs with data that will never change,
// set this variable to true for them and they will only be fetched once.
const cachedAsset = isStaticAsset && (await caches.match(event.request));
return cachedAsset || fetchAndCache(event.request);
})()
);
}
});
@vhscom
Copy link

vhscom commented Mar 17, 2022

Note timestamp replaced with version in 1.0.0-next.294 (changelog). I've noted this on the Mlocik97 example as well.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment