https://parivahanbharat.com/sw.js?v=4.0

1const CACHE_NAME = 'pb-pwa-cache-v5';
2
3// Core static assets to pre-cache immediately
4const PRECACHE_ASSETS = [
5  '/',
6  '/assets/css/style.css?v=3.6',
7  '/assets/js/app.js?v=2.4',
8  '/assets/img/parivahan-india.png',
9  '/assets/img/favicon.ico',
10  'https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Outfit:wght@600;700;800;900&display=swap'
11];
12
13// Install Event - Pre-cache core shell assets
14self.addEventListener('install', event => {
15  event.waitUntil(
16    caches.open(CACHE_NAME)
17      .then(cache => {
18        console.log('[Service Worker] Pre-caching core application shell');
19        return cache.addAll(PRECACHE_ASSETS);
20      })
21      .then(() => self.skipWaiting())
22  );
23});
24
25// Activate Event - Clean up any old caches
26self.addEventListener('activate', event => {
27  event.waitUntil(
28    caches.keys().then(cacheNames => {
29      return Promise.all(
30        cacheNames.map(cache => {
31          if (cache !== CACHE_NAME) {
32            console.log('[Service Worker] Clearing old cache:', cache);
33            return caches.delete(cache);
34          }
35        })
36      );
37    }).then(() => self.clients.claim())
38  );
39});
40
41// Fetch Event - Dynamic caching strategies based on request type
42self.addEventListener('fetch', event => {
43  const request = event.request;
44  const url = new URL(request.url);
45
46  // Ignore non-GET requests or external API analytics
47  if (request.method !== 'GET' || url.origin !== self.location.origin) {
48    return;
49  }
50
51  // Strategy 1: Network-First (with offline Cache Fallback) for HTML pages
52  if (request.headers.get('accept').includes('text/html')) {
53    event.respondWith(
54      fetch(request)
55        .then(response => {
56          // Clone the response and cache it
57          const responseClone = response.clone();
58          caches.open(CACHE_NAME).then(cache => cache.put(request, responseClone));
59          return response;
60        })
61        .catch(() => {
62          // If offline, serve the cached version of the request
63          return caches.match(request).then(cachedResponse => {
64            if (cachedResponse) {
65              return cachedResponse;
66            }
67            // Fallback to cached root if page is not cached
68            return caches.match('/');
69          });
70        })
71    );
72    return;
73  }
74
75  // Strategy 2: Cache-First / Stale-While-Revalidate for CSS, JS, and Static Assets
76  event.respondWith(
77    caches.match(request)
78      .then(cachedResponse => {
79        if (cachedResponse) {
80          // Fetch updated version in the background to update the cache (Stale-While-Revalidate)
81          fetch(request).then(networkResponse => {
82            if (networkResponse.status === 200) {
83              caches.open(CACHE_NAME).then(cache => cache.put(request, networkResponse));
84            }
85          }).catch(() => {/* Ignore network errors during stale updates */});
86          
87          return cachedResponse;
88        }
89
90        // Fetch from network if not in cache
91        return fetch(request).then(networkResponse => {
92          if (!networkResponse || networkResponse.status !== 200 || networkResponse.type !== 'basic') {
93            return networkResponse;
94          }
95          const responseToCache = networkResponse.clone();
96          caches.open(CACHE_NAME).then(cache => cache.put(request, responseToCache));
97          return networkResponse;
98        });
99      })
100  );
101});