Web APIs (navigator, geolocation, history)

navigator.registerProtocolHandler() registers web apps as protocol handlers: 1) It allows websites to handle specific URL schemes like mailto:, webcal:, or custom protocols, 2) This enables web applications to integrate with operating system functionality traditionally reserved for native apps, 3) For example, a webmail application could handle mailto: links clicked anywhere in the browser, 4) The browser typically prompts the user for permission before setting a handler, 5) The method requires parameters specifying the protocol and a URL template showing how to handle it, 6) Common use cases include email clients (mailto:), calendar apps (webcal:), and cryptocurrency wallets (bitcoin:), 7) It's part of the broader Web Platform API strategy to enable web apps to integrate more deeply with operating systems, 8) This capability is crucial for progressive web applications that aim to replace native applications.