I had the good fortune to receive Agile Web Development with Rails 4 from the publisher to review.

The book is really two books in one. The first is a walkthrough of building a simple Rails 4 application for an online bookstore. The second is a component by component look at Rails 4. If you want to be generous there’s a quick introduction to Ruby and Rails concepts at the beginning of the book.

The online bookstore walkthrough is interesting especially if you are new to Rails and the ideas behind Agile development. You take the role of a developer who is building an online bookstore for a client. You start off with a general idea of what needs to be done, but you build it incrementally, showing it to your customer at each step. Based on feedback you decide what to tackle next, such as showing pictures, getting details, or adding a shopping cart. Along the way there are some discussions of deployment, internationalization, authentication, and sending email.

Through the examples you learn the basics of creating Rails models, views, and controllers. Though the examples lean heavily on scaffolding to automatically generate the CRUD actions, you do extend it somewhat to handle XML and JSON responses. You also do some AJAX and automated testing. The book does stick pretty closely to the default Rails toolset including the test framework, though at the very end of the book there are some quick examples on using HAML for views.

At the end of each chapter are some exercises. Unlike many other books I found them to be of appropriate difficulty, with answers available online.

The second half of the book is a detailed look at the components of Rails. This is the more technical part of the book as it gets into specifics of how a request is processed and how a response is generated. There’s no bookstore application anymore, it’s just discussion of what’s available, code samples, and diagrams.

Along the way there are some interesting sidebars that explain some of the Rails philosophies or some real world scenarios. For example, one of the sidebars talks about when you want to use a database lookup that raises an exception on failure versus one that returns a nil or an empty set.

I didn’t read any of the previous editions so I can’t say with authority how much has changed. The book is up to date on the many changes that came in Rails 4 so it is current in that respect. However there are times when you read it and some older terminology, like fragment or page caching, creep in. This is more a matter of editing than it is about it being out of date, as the associated examples are correct. The index is fairly weak – many of the terms I tried to look up, including those featured on the back cover, were not found.

If you’re an experienced Rails developer this book will not help you much. But if you’re looking to get into Ruby on Rails, either from another language or even with a weak programming background, this book is an excellent way to get started. At a little over 400 pages it’ll take you a few weekends to get through depending on your skill level.