PWA Fundamentals Topic 25

Progressive Web Apps (PWAs) are web applications that use modern web capabilities to deliver an app-like experience to users. This lesson covers the foundational concepts of PWAs, focusing on essential features that enhance user engagement and performance.

1. Service Workers

Service workers are scripts that run in the background, separate from the web page, enabling features like push notifications and background sync.

2. Web App Manifest

The web app manifest is a JSON file that provides metadata about the application, such as its name, icons, and theme colors.

3. Responsive Design

PWAs must be responsive, adapting to various screen sizes and orientations to ensure a seamless user experience across devices.

Service Worker Registration

if ('serviceWorker' in navigator) {
    window.addEventListener('load', () => {
        navigator.serviceWorker.register('/service-worker.js')
            .then(registration => {
                console.log('Service Worker registered with scope:', registration.scope);
            })
            .catch(error => {
                console.error('Service Worker registration failed:', error);
            });
    });
}
                

Web App Manifest Example

{
    "name": "My PWA",
    "short_name": "PWA",
    "start_url": "/index.html",
    "display": "standalone",
    "background_color": "#ffffff",
    "theme_color": "#007bff",
    "icons": [
        {
            "src": "icon-192x192.png",
            "sizes": "192x192",
            "type": "image/png"
        },
        {
            "src": "icon-512x512.png",
            "sizes": "512x512",
            "type": "image/png"
        }
    ]
}
                

• Ensure your PWA is served over HTTPS.
• Implement a fallback for offline usage.
• Optimize images and assets for performance.
• Regularly test your PWA on various devices and browsers.