blob: 24d575a9171228a035123958b5dfd3f737e4fecc (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
|
// Some user agents only offer app installation if there is a SW and it handles
// offline requests.
const cacheVersion = "1.2";
const CACHE_NAME = `cache-v${cacheVersion}`;
// The resources cached by this service worker.
const resources = [
"user_preferences-member-manual.html",
"user_preferences-member-service-worker.js",
"resources/user_preferences-member-manual.js",
"resources/icon.png"
];
// 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));
});
|