The default ‘front end’ for Ruby On Rails applications takes the form of dynamically created web pages defined using HTML. In fact, it is not that difficult to create much slicker front ends rendered in Adobe Flash. This book explains how to get Flash talking to Rails with the help of Adobe’s Flex framework.

Assuming that the reader already has some basic knowledge of Ruby, Rails and Flex, the book moves rapidly on to the fundamental techniques of querying Rails from Flex and transferring data to and from Flex and Rails. It discusses testing and debugging, data visualization, source control and a broad range of other topics.

This is not the only book to cover Flex and Rails. The best known work on the topic is Peter Armstrong’s Flexible Rails. While these two books inevitably cover much of the same ground there are differences in approach. In general, I’d say that Armstrong’s book is more of a progressive tutorial which assumes that the reader will work along in sequence whereas ‘Flex On Rails’ is more topic-based, making it easier to dip into chapters in random order.

While, in principle, this book describes the two frameworks - Flex and Rails - rather than any specific IDEs, it really generally assumes that the reader will be using the Adobe Flex Builder IDE (in some chapters the Professional edition is required) for Flex development. Moreover, in common with many Ruby-centric writers, the authors of this book give scant attention to the concerns of Windows programmers. As one of the developers of the Ruby In Steel (Rails) and Amethyst (Flex) IDEs for Visual Studio, I must admit that I consider it odd that neither of our IDEs merits so much a mention. In fact, the index only mentions Windows four times - all of which reference minor details relating to the installation of Ruby and related tools.

Overall, this provides a decent overview of using Flex with Rails. Bear in mind, however, that Rails is still something of a moving target; its features are frequently changed or deprecated in new releases which has the unfortunate side-effect of making books on Rails go out of date with depressing speed. So it’s worth keeping an eye on the authors’ blog which alerts readers to problems, and solutions, that may arise when using programs from the book with the latest versions of Rails: http://blog.flexonrails.com.