Recommended Reading: Flex on Rails (Addison-Wesley)

Disclaimer: Addison-Wesley sent me (unsolicited) a review copy of this book at no charge, with the tacit assumption being that I would read it and review it publicly. There are no conditions, however, on the content of said review. What you are about to read is my unbiased, unvarnished take on this book, written to inform you, not to curry favor with the publisher or the authors. Also, I do not have any business relationship with any of the parties involved in the publication of this book; I will not gain in any way if you choose to buy it. But, as it happens with this book, I believe you will gain if you choose to buy it. Here's why:

The Good

Flex on Rails, by Tony Hillerson and Daniel Wanja, does many important things right, tech-book-wise, which I find astonishing; more so given that it's the first book by both authors. The material strikes an effective balance between easy-to-absorb and useful-in-real-life, without spending too much time at either extreme, and -- mercifully -- no time at all in "Hello World".

Aside to would-be (and a lot of already-are) tech book authors: Read Chapter 1 of this book -- all seven pages of it -- to see how it's done. Notice how much (read: "how little") time and print is expended on rehashing yet again the minute details of installing Ruby, RubyGems, Rails, and other requirements. This is not one of those books that has chosen to pad its page count by wallowing in the comfort zone of a twenty-page "Getting Started" tutorial.

Chapter 1 sets the tone. Subsequent material flows naturally, and never overwhelms. Chapters 2 and 3 combine effectively to introduce the concepts of Flex and Rails' use of XML and REST to communicate betwixt themselves, but without the seemingly-obligatory over-exposition of the history and motivation of either XML or REST.

The authors introduce testing early on (Chapter 4); not quite TDD, but not bad either, for a tech book. A brief detour into RubyAMF (Chapter 5) follows, and then we get another key topic, Debugging (Chapter 6), early enough to be useful but not so early as to be overwhelming.

Throughout this first part of the book, the authors assume a fair amount of Rails knowledge/experience. For example, Chapter 2 ("Passing Data with XML") jumps right in with a sample Rails app, complete with (minimal) scaffolding and a simple database migration. Rather than bog the reader down with minutiae, as far too many other tech books do, this material is presented with an unforced, matter-of-fact tone that assumes reader familiarity, but doesn't condescend. Now I concede that I'm an experienced Rails developer, so I take this stuff for granted. But I believe that someone new to Rails would not be overwhelmed. And -- key point here -- there are other, better resources for learning about Rails' scaffolding and migrations. An ill-timed dissertation here would just turn off seasoned developers entirely and distract any new kids in the audience. Good for Tony and Daniel (and whatever wise editors they worked with) for avoiding this all-too-familiar trap.

The second half of the book demonstrates another key concept that too many tech books don't bother with, and one that I think this team just nailed: Flex on Rails is not an introductory tutorial, and it's not an advanced recipe book: it's both! Each of Chapters 10 through 22 presents a solution to a problem that is very likely to crop up in any real-world usage of this technology. To name a few:

• Source Control (Chapter 10), including Subversion and Git


• Deployment (Chapter 12), largely with Capistrano


• Authenticating (Chapter 15)


• Communicating between Flex and JavaScript (Chapter 21)


• File Upload (Chapter 22)

I've saved mentioning my favorite chapter for last, and I think it is just way too cool that it's in the book, because it reflects a personal mantra of mine -- Chapter 13: "Read the Source!" I am constantly preaching this, whether it's Rails, or Capistrano, or JRuby, or even Ruby. Open source software is a treasure trove of HOWTO: Write Code in all its glory. It is a cornucopia, constantly replenished by the experience and learnings and mistakes and refactorings and holy wars of a horde of extremely bright and capable programmers. Is it sometimes flawed? Sure. But it's there. And it's the best source of education in computer programming -- both how to and how not to -- that you have available to you. Use it.

The Bad

Not a lot to write here. I've long since ceased to be as outraged as I used to be about the computer publishing industry's contempt for (okay -- let's be charitable and call it "indifference towards") the English language. Let's just say I won't be letting my son use this or any tech book as a primer in either spelling or grammar. This book is not as bad as some, but it still has its share of sloppy copy editing -- typos here, unfortunate typesetting choices there (primarily inconsistent/inadequate use of fixed-width fonts or otherwise visually highlighting stuff that's best viewed as code and not prose).

The Meh

For a book that seems to have been designed deliberately to respect its target audience's intelligence and skill level, Chapter 8 ("Flex MVC Frameworks") takes a bit of a detour into Probably Should Be Obvious Land in its coverage of the Model-View-Controller paradigm. Yes, it's in the context of describing how Cairngorm and PureMVC specifically do MVC, but come on -- it's MVC. Even here, though, the authors rise above the average tech book experience, by implementing the same app using both frameworks, so you can compare and contrast and maybe get a sense for which framework fits your needs better.

Gratuitous Name-Dropping Reference

Tony Hillerson and I worked on a Rails project (my first) together a few years ago, and even then he was valiantly (but alas, in vain) trying to convince his partners to let us use Flex for the UI. I'm glad to see him realizing that dream and in fact thriving on it. I've met Daniel briefly, at the Pragmatic Studio's Cocoa Programming class in Denver, but I don't think he knows who I am. Other than that, I have no business relationship with either, and I do not stand to benefit in any way from the sales of their book. But, as I said in my disclaimer above, I believe that you will benefit from buying it. Let me know if you do. And let me know how it goes.