https://bethechangepk.org.uk/sw.js

1//remember to increment the version # when you update the service worker
2const version = "1.01",
3    preCache = "PRECACHE-" + version,
4    cacheList = [ "/" ];
5
6/*
7create a list (array) of urls to pre-cache for your application
8*/
9
10/*  Service Worker Event Handlers */
11
12self.addEventListener( "install", function ( event ) {
13
14    console.log( "Installing the service worker!" );
15
16    self.skipWaiting();
17
18    caches.open( preCache )
19        .then( cache => {
20
21            cache.addAll( cacheList );
22
23        } );
24
25} );
26
27self.addEventListener( "activate", function ( event ) {
28
29    event.waitUntil(
30
31        //wholesale purge of previous version caches
32        caches.keys().then( cacheNames => {
33            cacheNames.forEach( value => {
34
35                if ( value.indexOf( version ) < 0 ) {
36                    caches.delete( value );
37                }
38
39            } );
40
41            console.log( "service worker activated" );
42
43            return;
44
45        } )
46
47    );
48
49} );
50
51/*
52self.addEventListener( "fetch", function ( event ) {
53
54    console.log(event);
55    
56    event.respondWith(
57
58        
59        fetch( event.request )
60
61        // check the cache first, then hit the network 
62        
63                caches.match( event.request )
64                .then( function ( response ) {
65
66                    if ( response ) {
67                        return response;
68                    }
69
70                    return fetch( event.request );
71                } )
72        
73        
74    );
75    
76
77    
78
79
80} );
81
82*/
83
84
85/* service worker resources
86
87https: //love2dev.com/blog/what-is-the-service-worker-cache-storage-limit/
88https: //love2dev.com/blog/service-worker-cache/
89
90*/