Building Polyfills

Add custom features to browsers old and new by writing polyfill libraries, JavaScript plugins that take browsers beyond their native capabilities. In this practical fieldbook, author Brandon Satrom introduces principles and guidelines for polyfill development, and then walks you through the steps for building a complex, real-world HTML5 polyfill.

You’ll also explore the future of polyfilling—or prollyfilling—that will enable you to test and work with emerging concepts, often ahead of browser vendors. By the time you finish this book, you’ll have the tools and hands-on experience you need to build reliable polyfills for today’s and tomorrow’s Web.

• Learn the current state of polyfills, including shims, opt-ins, and drop-ins
• Use principles and practices to build responsible polyfills that benefit the entire web development community
• Build out several features for an HTML5 Forms polyfill library
• Configure a build environment and run automated cross-browser testing
• Optimize performance, handle edge cases, and fine-tune the speed of your polyfill
• Get examples of prollyfilling libraries that push the boundaries of the Web
• Write a sample prollyfill and compare it to current polyfill builds

Table of Contents

Part I: Building Polyfills
Chapter 1. The Current State of Web Polyfills
Chapter 2. Principles and Practices of Polyfill Development
Chapter 3. Building Your First Polyfill, Part 1: Getting Started
Chapter 4. Building Your First Polyfill, Part 2: Build Workflows and Cross-Browser Testing
Chapter 5. Building Your First Polyfill, Part 3: Performance and Edge-Case Testing

Part II: Prollyfilling and the Future of the Web Platform
Chapter 6. The Future of Polyfilling
Chapter 7. Building Your First Prollyfill