https://www.atlasofmutualheritage.nl/cotonic-service-worker.js

1/**
2 * Copyright 2016-2023 The Cotonic Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS-IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17"use strict";
18
19self.addEventListener('install', (event) => {
20    event.waitUntil( self.skipWaiting() );
21});
22
23self.addEventListener('activate', (event) => {
24    event.waitUntil( self.clients.claim() );
25});
26
27self.addEventListener('fetch', (event) => {
28    // Firefox 88 is failing downloads for large requests over slower
29    // connections if the service worker handles the fetch event.
30    // Temporarily disabled the code below to fix this issue.
31    //
32    // if (   !event.request.headers.get('range')
33    //     && !event.request.headers.get('x-no-cache')) {
34    //     // fetch drops the 'range' header, which is used
35    //     // with video and audio requests.
36    //     event.respondWith( fetch( event.request ) );
37    // }
38});
39
40self.addEventListener('message', (event) => {
41    switch (event.data.type)  {
42        case "broadcast":
43            // Relay broadcast messages
44            const message = event.data;
45            message.sender_id = event.source.id;
46
47            event.waitUntil(messageClients(message));
48            break;
49        default:
50            console.info("Service Worker: unknown message", event);
51    }
52});
53
54self.addEventListener('push', (event) => {
55    const message = event.data.json();
56
57    switch(message.type) {
58        case "notification":
59            const data = message.data;
60            self.registration.showNotification(data.title, data.options);
61            break;
62        default:
63            console.info("Service Worker: unknown push message", event);
64    }
65});
66
67self.addEventListener("notificationclick", (event) => {
68    const notification = event.notification;
69    const localURL = ensureLocalURL(notification.data?notification.data.url:undefined);
70    event.waitUntil(focusWindow(localURL));
71});
72
73
74// Try to focus a tab with the given url. When such a tab is not found,
75// a new one will be opened.
76function focusWindow(url)  {
77    return clients.matchAll({ type: "window" })
78        .then((clientList) => {
79            // Check if there already is a tab with has this url open.
80            for(const client of clientList) {
81                if((client.url === url) && ('focus' in client)) {
82                    return client.focus();
83                }
84            }
85
86            if (clients.openWindow) {
87                return clients.openWindow(url);
88            }
89        });
90}
91
92// Relay a message to all clients (including the sender)
93function messageClients( message ) {
94    return self.clients.matchAll()
95        .then((clientList) => {
96            clientList.forEach((client) => {
97                client.postMessage(message);
98            })
99        });
100}
101
102// Ensure that a local url is returned to prevent cross
103// origin navigations from a notification.
104function ensureLocalURL(url) {
105    let parsed;
106
107    if(url) {
108        parsed = new URL(url, self.origin);
109    }
110
111    if((parsed === undefined) || (parsed.origin !== self.origin)) {
112        parsed = new URL("/", self.origin);
113    }
114
115    return parsed.toJSON();
116}