Building Progressive Web Apps

# Building Progressive Web Apps Progressive Web Apps (PWAs) combine the best of web and mobile apps. They're fast, reliable, and engaging. ## Core Features of PWAs 1. **Responsive**: Works on any device 2. **Offline-capable**: Functions without internet 3. **App-like**: Feels like a native app 4. **Fresh**: Always up-to-date 5. **Safe**: Served over HTTPS 6. **Discoverable**: Searchable as websites 7. **Installable**: Add to home screen ## Service Worker The heart of a PWA: ```javascript // sw.js self.addEventListener('install', (event) => { event.waitUntil( caches.open('v1').then((cache) => { return cache.addAll([ '/', '/styles.css', '/script.js', '/offline.html' ]); }) ); }); self.addEventListener('fetch', (event) => { event.respondWith( caches.match(event.request).then((response) => { return response || fetch(event.request); }) ); }); ``` ## Web App Manifest ```json { "name": "My PWA", "short_name": "PWA", "start_url": "/", "display": "standalone", "background_color": "#ffffff", "theme_color": "#2196F3", "icons": [ { "src": "/icon-192.png", "sizes": "192x192", "type": "image/png" }, { "src": "/icon-512.png", "sizes": "512x512", "type": "image/png" } ] } ``` ## Caching Strategies ### Cache First ```javascript event.respondWith( caches.match(event.request) .then(response => response || fetch(event.request)) ); ``` ### Network First ```javascript event.respondWith( fetch(event.request) .catch(() => caches.match(event.request)) ); ``` ## Push Notifications ```javascript self.addEventListener('push', (event) => { const data = event.data.json(); self.registration.showNotification(data.title, { body: data.body, icon: '/icon.png' }); }); ``` ## Benefits - Improved performance - Offline functionality - Increased engagement - Lower development cost than native apps PWAs represent the future of web applications. Start building one today!