https://www.dot-see.com/sw.js

1const cacheVersion = 'grow-1.1.1';
2
3self.addEventListener('install', function (evt) {
4    skipWaiting();
5    evt.waitUntil(precache());
6});
7
8self.addEventListener('fetch', function (evt) {
9    const request = evt.request;
10
11    // Ignore requests for back office-related URLs
12    if (request.url.includes('/umbraco')) {
13        return;
14    }
15    if (request.url.includes('/sb')) {
16        return;
17    }
18    if (request.url.includes('/App_Plugins')) {
19        return;
20    }
21
22    // Ignore non-GET requests
23    if (request.method !== 'GET') {
24        return;
25    }
26
27    // Ignore all requests to Google Analytics
28    if (request.url.search('google-analytics.com') != -1) {
29        return;
30    }
31
32    // Block chrome extension scripts
33    if (request.url.search('extension:') != -1) {
34        return;
35    }
36
37    // Ignore video requests because of Safari's range bug
38    // https://philna.sh/blog/2018/10/23/service-workers-beware-safaris-range-request/
39    if (request.url.match(/\.(mp4)$/)) {
40        return;
41    }
42
43    evt.respondWith(fromCache(request));
44});
45
46function precache() {
47    // Delete old caches
48    caches.keys().then(function (names) {
49        [].forEach.call(names, function (name) {
50            if (name != cacheVersion) {
51                caches.delete(name);
52            }
53        });
54    });
55
56    // Cache homepage
57    return caches.open(cacheVersion).then(function (cache) {
58        // Cache everything
59        return cache.addAll([
60            '/'
61        ]);
62    });
63}
64
65function fromCache(request) {
66    // Network first: for pages
67    if (request.destination == 'document') {
68        return fetch(request).then(function (response) {
69            let responseClone = response.clone();
70
71            caches.open(cacheVersion).then(function (cache) {
72                cache.put(request, responseClone);
73            });
74
75            return response;
76        }).catch(function () {
77            return caches.open(cacheVersion).then(function (cache) {
78                return cache.match(request).then(function (matching) {
79                    if (matching) {
80                        return matching;
81                    }
82                });
83            });
84        });
85    }
86
87    // Cache first: For everything else
88    return caches.open(cacheVersion).then(function (cache) {
89        return cache.match(request).then(function (matching) {
90            if (matching) {
91                return matching;
92            } else {
93                // Update cache if online
94                return fetch(request).then(function (response) {
95                    let responseClone = response.clone();
96                    caches.open(cacheVersion).then(function (cache) {
97                        cache.put(request, responseClone);
98                    });
99                    return response;
100                });
101            }
102        }).catch(function () {
103            // Serve offline asset if not online
104            if (request.url.match(/\.(jpe?g|png|gif|svg)$/)) {
105                return missingImage(request);
106            }
107            return;
108        });
109    });
110}
111
112function missingImage(request) {
113    if (navigator.onLine === false) {
114        return new Response(`
115            <svg role="img" aria-labelledby="offline-title" viewBox="0 0 400 300" xmlns="http://www.w3.org/2000/svg" preserveAspectRatio="xMidYMid slice">
116                <title id="offline-title">Offline</title>
117                <g fill="none" fill-rule="evenodd">
118                    <path fill="#000e29" d="M0 0h400v300H0z"/>
119                    <text fill="#878787" font-family="Helvetica Neue,Arial,Helvetica,sans-serif" font-size="72" font-weight="normal">
120                        <tspan x="93" y="172">offline</tspan>
121                    </text>
122                </g>
123            </svg>`,
124            {
125                headers: {
126                    'Content-Type': 'image/svg+xml',
127                    'Cache-Control': 'no-store'
128                }
129            }
130        );
131    } else {
132        return fetch(request).then(function (response) {
133            return response;
134        });
135    }
136}