Source code
Revision control
Copy as Markdown
Other Tools
// Some user agents only offer app installation if there is a SW and it handles
// offline requests.
const cacheVersion = "1.1";
const CACHE_NAME = `cache-v${cacheVersion}`;
// The resources cached by this service worker.
const resources = [
"protocol_handlers-member-service-worker.js",
"protocol_handlers-member-manual.tentative.html",
"resources/icon.png",
"resources/protocol_handlers_entry.html",
];
// Load all resources for this service worker.
const precache = async () => {
const cache = await caches.open(CACHE_NAME);
await cache.addAll(resources);
};
// Get a resource from the cache.
const fromCache = async request => {
const cache = await caches.open(CACHE_NAME);
return await cache.match(request.url);
};
// Attempt to get resources from the network first, fallback to the cache if we're
// offline.
const networkFallbackToCache = async request => {
try {
const response = await fetch(request);
if (response.ok) return response;
} catch (err) {}
return await fromCache(request);
};
// When we have a new service worker, update the caches and swap immediately.
self.addEventListener("install", e => {
e.waitUntil(precache().then(() => self.skipWaiting()));
});
// Claim existing clients.
self.addEventListener("activate", e => {
e.waitUntil(self.clients.claim());
});
// When a resource need to be fetched, check whether it is
// contained in the cache and return the cached version, otherwise
// get it from the network.
self.addEventListener("fetch", e => {
e.respondWith(networkFallbackToCache(e.request));
});