Rails just keeps on changing. Rails 3 and Ruby 1.9 bring hundreds of improvements, including new APIs and substantial performance enhancements. The fourth edition of this award-winning classic has been reorganized and refocused so it's more useful than ever before for developers new to Ruby and Rails. Rails 3 is a major release--the changes aren't just incremental, but structural. So we decided to follow suit. This book isn't just a mild reworking of the previous edition to make it run with the new Rails. Instead, it's a complete refactoring. You'll still find the Depot example at the front, but you'll also find testing knitted right in. Gone are the long reference chapters--that's what the web does best. Instead you'll find more targeted information on all the aspects of Rails that you'll need to be a successful Web developer. Now Updated for Rails 3.2 Rails 3.1 and Rails 3.2 introduce many user-facing changes, and this release has been updated to match all the latest changes and new best practices in Rails 3.1 and Rails 3.2. This includes full support for Ruby 1.9.2 hash syntax; incorporation of the new Sprockets 2.0 Asset Pipeline, including SCSS and CoffeeScript; jQuery now being the default; reversible migrations; JSON response support; Rack::Cache, and much more. Ruby on Rails helps you produce high-quality, beautiful-looking web applications quickly. You concentrate on creating the application, and Rails takes care of the details. Tens of thousands of developers have used this award-winning book to learn Rails. It's a broad, far-reaching tutorial and reference that's recommended by the Rails core team. If you're new to Rails, you'll get step-by-step guidance. If you're an experienced developer, this book will give you the comprehensive, insider information you need. Rails has evolved over the years, and this book has evolved along with it. We still start with a step-by-step walkthrough of building a real application, and in-depth chapters look at the built-in Rails features. This edition now gives new Ruby and Rails users more information on the Ruby language and takes more time to explain key concepts throughout. Best practices on how to apply Rails continue to change, and this edition keeps up. Examples use cookie backed sessions, HTTP authentication, and Active Record-based forms, and the book focuses throughout on the right way to use Rails. Additionally, this edition now reflects Ruby 1.9, a new release of Ruby with substantial functional and performance improvements.