Flexible Rails

Adobe’s Flex and Ruby On Rails are two of the most fashionable web technologies at the moment. Flex enables programmers to create slick interactive applications in a browser or on the desktop - typically using a graphic front-end rendered using Flash. Ruby On Rails is a combination of a database-driven web application framework (Rails) and a dynamic programming language (Ruby) - typically it uses a standard HTML front-end created using HTML templates which can be controlled using the Ruby language. You might be forgiven for thinking that Flex and Ruby On Rails are two mutually exclusive technologies. Not so! Peter Armstrong’s book explains how you can create a Rails application to handle most of the data manipulation tasks and link it into a Flex-based front end.

The book teaches Flex/Rails programming by developing a fairly complex ‘To Do List’ application in incremental stages. The author’s stated aim is to create an application with “enough features to demonstrate a significant subset of Flex and Rails features but [which will be] small enough and with a simple enough domain to be fully understood while learning the frameworks and how they interact.”

There are pros and cons in this approach. On the plus side, the reader will be able to follow along with every stage of the development of a ’real world’ application - one which, by the end of the book will be genuinely useful and ready to deploy. On the minus side, this means that you have to commit yourself to sequential study of the text. If you miss out some chapters you will probably miss out on some important details which will prevent you understanding the code that follows. If you are prepared to put in the effort, this will be a fine and rewarding book. But if you prefer the sort of tutorial that lets you ‘dip into’ subject areas in random order - the ‘programming recipes’ approach - ‘Flexible Rails’ may be less satisfactory.

To some extent, you can skip over topics with which you are already familiar since the source code of the project is supplied in the state of development corresponding to each chapter. This means you can load up the code from a previous chapter and then start modifying it by following the author’s instructions.

Personally, I found the first few chapters heavy going. This is due to the fact that a big leap is made from a simple Flex/Rails ‘Hello world’ to a pretty complicated password-verified login system. This is a steep slope for a newcomer to Flex on Rails to climb. Fortunately, once you’ve got over this, the rest of the book proceeds at a somewhat less arduous pace.

So what prior knowledge would you need to make good use of ‘Flexible Rails’? While you might (just about) approach this book even if you have no prior knowledge of Rails or Flex, it would be a significant advantage if you were at least familiar with the basics of Ruby programming and had taken the time to try creating one or two simple non-Flex Rails applications. There are plenty of web tutorials on these subjects (I’ve even written a few myself - for example, my free eBook, The Little Book Of Ruby). On the Flex side of the equation, you would be well advised to try out Adobe’s Flex development environment, FlexBuilder (there is a free 60-day evaluation) and read some of the comprehensive documentation available on the Adobe site. A basic familiarity with XML and the Flex programming language, ActionScript (or JavaScript which it closely resembles) would also be useful.

If you want to know how to use Flex with Ruby On Rails, this book is currently your only source of really in-depth information. As I said earlier, it’s not a ‘light read’ but, ultimately, it’s worth the effort.