Files
nextsnap/app/static/sw.js
kamaji 37f417eb5b Fix SW scope to intercept page navigations for offline support
The SW was served from /static/sw.js with default scope /static/,
so it only intercepted static asset requests. Page navigations to
/capture, /queue, /browser were not handled by the SW at all —
Safari showed its native offline error.

Fix: serve SW from /sw.js route with Service-Worker-Allowed: / header
and register with scope: /. Now the SW intercepts all navigations and
serves the offline fallback page when the network is unavailable.

Also remove auth-protected page routes from precache (they would cache
the login redirect). Pages are cached via network-first on visit instead.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
2026-02-07 22:16:07 -06:00

174 lines
6.4 KiB
JavaScript

// NextSnap Service Worker
// Provides offline-first caching for the app shell
const CACHE_VERSION = 'nextsnap-v22';
const APP_SHELL_CACHE = 'nextsnap-shell-v18';
const RUNTIME_CACHE = 'nextsnap-runtime-v18';
// Offline fallback page (served when network fails and no cached version exists)
const OFFLINE_PAGE = `<!DOCTYPE html>
<html lang="en"><head>
<meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1">
<title>Offline - NextSnap</title>
<style>
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:-apple-system,system-ui,sans-serif;background:#1a1a2e;color:#e0e0e0;
display:flex;align-items:center;justify-content:center;min-height:100vh;padding:2rem;text-align:center}
h1{font-size:1.5rem;margin-bottom:1rem;color:#fff}
p{color:#aaa;margin-bottom:1.5rem;line-height:1.5}
button{background:#4dabf7;color:#fff;border:none;padding:0.75rem 2rem;border-radius:8px;
font-size:1rem;cursor:pointer;min-height:44px}
button:active{opacity:0.8}
</style></head><body>
<div><h1>You're Offline</h1><p>Check your internet connection and try again.</p>
<button onclick="location.reload()">Retry</button></div>
</body></html>`;
// Assets to cache on install
const APP_SHELL_ASSETS = [
'/static/css/style.css',
'/static/js/app.js',
'/static/js/auth.js',
'/static/js/camera.js',
'/static/js/storage.js',
'/static/js/sync.js',
'/static/js/filebrowser.js',
'/static/lib/dexie.min.js',
'/static/manifest.json',
'/static/icons/icon-192.png',
'/static/icons/icon-512.png'
];
// Install event - precache app shell
self.addEventListener('install', (event) => {
console.log('[SW] Installing service worker...');
event.waitUntil(
caches.open(APP_SHELL_CACHE)
.then((cache) => {
console.log('[SW] Caching app shell');
return cache.addAll(APP_SHELL_ASSETS);
})
.then(() => {
console.log('[SW] App shell cached successfully');
return self.skipWaiting(); // Activate immediately
})
.catch((error) => {
console.error('[SW] Failed to cache app shell:', error);
})
);
});
// Activate event - clean up old caches
self.addEventListener('activate', (event) => {
console.log('[SW] Activating service worker...');
event.waitUntil(
caches.keys()
.then((cacheNames) => {
return Promise.all(
cacheNames.map((cacheName) => {
if (cacheName !== APP_SHELL_CACHE && cacheName !== RUNTIME_CACHE) {
console.log('[SW] Deleting old cache:', cacheName);
return caches.delete(cacheName);
}
})
);
})
.then(() => {
console.log('[SW] Service worker activated');
return self.clients.claim(); // Take control immediately
})
);
});
// Fetch event - route requests to appropriate caching strategy
self.addEventListener('fetch', (event) => {
const { request } = event;
const url = new URL(request.url);
// Skip non-GET requests (uploads, form posts, etc.)
if (request.method !== 'GET') {
return;
}
// Static assets (/static/) - cache-first (versioned via SW cache bump)
if (url.pathname.startsWith('/static/')) {
event.respondWith(
caches.match(request)
.then((cachedResponse) => {
if (cachedResponse) {
return cachedResponse;
}
return fetch(request)
.then((response) => {
if (!response || response.status !== 200) {
return response;
}
const responseClone = response.clone();
caches.open(APP_SHELL_CACHE).then((cache) => {
cache.put(request, responseClone);
});
return response;
})
.catch(() => new Response('Offline', { status: 503 }));
})
);
return;
}
// Everything else (pages, API) - network-first with cache fallback
event.respondWith(
fetch(request)
.then((response) => {
// Cache successful GET responses for offline fallback
if (response.status === 200) {
const responseClone = response.clone();
caches.open(RUNTIME_CACHE).then((cache) => {
// Don't cache file uploads or large binary responses
if (!url.pathname.includes('/upload') &&
!url.pathname.includes('/thumbnail')) {
cache.put(request, responseClone);
}
});
}
return response;
})
.catch(() => {
// Network failed - try cache
return caches.match(request)
.then((cachedResponse) => {
if (cachedResponse) {
return cachedResponse;
}
// No cache - return offline response
if (url.pathname.startsWith('/api/')) {
return new Response(
JSON.stringify({ error: 'offline', message: 'You are offline.' }),
{ status: 503, headers: { 'Content-Type': 'application/json' } }
);
}
return new Response(OFFLINE_PAGE, {
status: 200,
headers: { 'Content-Type': 'text/html' }
});
});
})
);
});
// Listen for messages from clients
self.addEventListener('message', (event) => {
if (event.data && event.data.type === 'SKIP_WAITING') {
self.skipWaiting();
}
if (event.data && event.data.type === 'CLEAR_CACHE') {
event.waitUntil(
caches.keys().then((cacheNames) => {
return Promise.all(
cacheNames.map((cacheName) => caches.delete(cacheName))
);
})
);
}
});