📡 You're Offline
SFM requires an internet connection for this page.
Please check your connection and try again.
`,
{
headers: { 'Content-Type': 'text/html' }
}
);
}
// For other requests, return error
return new Response('Network error', {
status: 503,
statusText: 'Service Unavailable'
});
}
}
// Cache-first strategy
async function cacheFirstStrategy(request, cacheName) {
const cachedResponse = await caches.match(request);
if (cachedResponse) {
return cachedResponse;
}
// Not in cache, fetch from network
try {
const networkResponse = await fetch(request);
// Cache successful responses
if (networkResponse && networkResponse.status === 200) {
const cache = await caches.open(cacheName);
cache.put(request, networkResponse.clone());
}
return networkResponse;
} catch (error) {
console.error('[SW] Fetch failed:', request.url, error);
return new Response('Network error', {
status: 503,
statusText: 'Service Unavailable'
});
}
}
// Check if URL is a static asset
function isStaticAsset(pathname) {
const staticExtensions = ['.css', '.js', '.png', '.jpg', '.jpeg', '.svg', '.ico', '.woff', '.woff2'];
return staticExtensions.some(ext => pathname.endsWith(ext));
}
// Background Sync - for offline edits
self.addEventListener('sync', (event) => {
console.log('[SW] Background sync event:', event.tag);
if (event.tag === 'sync-edits') {
event.waitUntil(syncPendingEdits());
}
});
// Sync pending edits to server
async function syncPendingEdits() {
console.log('[SW] Syncing pending edits...');
try {
// Get pending edits from IndexedDB
const db = await openDatabase();
const edits = await getPendingEdits(db);
if (edits.length === 0) {
console.log('[SW] No pending edits to sync');
return;
}
console.log(`[SW] Syncing ${edits.length} pending edits`);
// Send edits to server
const response = await fetch('/api/sync-edits', {
method: 'POST',
headers: {
'Content-Type': 'application/json'
},
body: JSON.stringify({ edits })
});
if (response.ok) {
const result = await response.json();
console.log('[SW] Sync successful:', result);
// Clear synced edits from IndexedDB
await clearSyncedEdits(db, result.synced_ids || []);
// Notify all clients about successful sync
const clients = await self.clients.matchAll();
clients.forEach(client => {
client.postMessage({
type: 'SYNC_COMPLETE',
synced: result.synced
});
});
} else {
console.error('[SW] Sync failed:', response.status);
}
} catch (error) {
console.error('[SW] Sync error:', error);
throw error; // Will retry sync later
}
}
// IndexedDB helpers (simplified versions - full implementations in offline-db.js)
function openDatabase() {
return new Promise((resolve, reject) => {
const request = indexedDB.open('sfm-offline-db', 1);
request.onerror = () => reject(request.error);
request.onsuccess = () => resolve(request.result);
request.onupgradeneeded = (event) => {
const db = event.target.result;
if (!db.objectStoreNames.contains('pending-edits')) {
db.createObjectStore('pending-edits', { keyPath: 'id', autoIncrement: true });
}
};
});
}
function getPendingEdits(db) {
return new Promise((resolve, reject) => {
const transaction = db.transaction(['pending-edits'], 'readonly');
const store = transaction.objectStore('pending-edits');
const request = store.getAll();
request.onsuccess = () => resolve(request.result);
request.onerror = () => reject(request.error);
});
}
function clearSyncedEdits(db, editIds) {
return new Promise((resolve, reject) => {
const transaction = db.transaction(['pending-edits'], 'readwrite');
const store = transaction.objectStore('pending-edits');
editIds.forEach(id => {
store.delete(id);
});
transaction.oncomplete = () => resolve();
transaction.onerror = () => reject(transaction.error);
});
}
// Message event - handle messages from clients
self.addEventListener('message', (event) => {
console.log('[SW] Message received:', event.data);
if (event.data.type === 'SKIP_WAITING') {
self.skipWaiting();
}
if (event.data.type === 'CLEAR_CACHE') {
event.waitUntil(
caches.keys().then((cacheNames) => {
return Promise.all(
cacheNames.map((cacheName) => caches.delete(cacheName))
);
})
);
}
});
console.log('[SW] Service Worker loaded');