The File Web Share Target API is a new, powerful feature in Chrome Canary that allows web apps to receive files (like images) shared from other apps, much like native apps. This post details how I implemented this API on my blog, enabling direct image uploads from my Android camera app. The process involves declaring support for file sharing in your web app manifest and handling the incoming file data in a service worker. The API uses a progressive approach, leveraging standard form POST requests, making integration relatively simple. This feature significantly enhances web app integration with the host operating system, closing the gap between web and native apps.
In the early days of mobile web development, Google Gears played a pivotal role in shaping the APIs we use today. It introduced concepts like local caching, local databases, and background processing, which paved the way for modern APIs such as AppCache, WebSQL, Geolocation, and Web Workers. While WebSQL and AppCache have been replaced by IndexedDB and ServiceWorkers, respectively, the legacy of Gears is undeniable.
Workbox helps developers understand and manage storage quota issues, particularly those related to runtime caching of opaque responses. Opaque responses, which are cross-origin responses without CORS enabled, consume a disproportionately large amount of storage quota due to browser security measures. This can lead to unexpected quota issues for developers. Workbox addresses this problem by informing developers about the impact of opaque responses on storage, enabling them to optimize their service worker caching strategies.
This blog post discusses the implementation of a Service Worker for my blog, with a focus on the caching strategy. I've chosen a "Stale While Revalidate" approach, which prioritizes speed and resilience. The Service Worker intercepts network requests and serves cached content if available, while simultaneously fetching updated content in the background. This ensures the latest version is available after one refresh. The post also details the requirements considered when choosing this strategy, including development simplicity and compatibility with the existing hosting setup (Hugo and NGINX). The provided JavaScript code snippet demonstrates the Service Worker implementation.