Ajax Patterns and Best Practices

Many Ajax books have come to press this year and this one is an exception because it explains Ajax from an architecture style as opposed from a development style. What this means is that the book explains how REST is used in developing Ajax web applications. REST is a style on how to send data between a client and a server. Until now, the basics client/server or browser/server requests has been the same for years no matter what server technology you use (ASP, PHP, and JSP). With Ajax the way data is passed and retrieved to the client id different now. So, the way we architect web applications must be different too. Common sense right? Well, this is the first book that I've seen so far that explains Ajax in this way. The first chapter goes into an overview of Ajax and how it has changed how web applications work. It gives some good examples of various Google web applications and explains how the data is sent to the client behind the scenes. It also talks about the various architectural styles of development. The second chapter starts focuses on REST theory and data will be sent via the XMLHttpRequest object. It gives a good detailed explanation of the methods and properties and a sample class written in JavaScript that can be used. It also illustrates a debugging process of this class (in Firebox) and shows you how to run through the different states of the XMLHttpRequest. The third chapter reviews a new pattern ("content chunking") which the author shows you how to incrementally build an HTML page while separating the logic so that each section of the site can be loaded by user interaction. It's something I've never even thought about as I've recently read different Ajax books. Unfortunately, I cannot go into detail of this chapter (otherwise I'd be writing a book), but believe me it is an eye opener. The fourth chapter reviews another pattern ("cache controller") which is the pattern how Google created Google Maps in how the site temporarily stores data per session. This is another reason to buy this book as well. Again, I've never seen this methodology discussed in any other Ajax book. The rest of the book goes through other patterns in developing Ajax web applications that will enlighten you in helping you create the next generation of web apps (web 2.0). This book is skinny (less than 400), but each chapter really goes straight to the point in explaining each pattern and how Ajax can really be used correctly. A definite must buy for any web developer wanting to truly understand Ajax.

Buy whatever Ajax primer you want, work with it, get excited about it, but before you use it in a real application, buy and read this book. Never expect to learn about a subject from a patterns book, just expect to leapfrog some painful learning experiences. This book helps you jump from experienced beginner to reasonable competence status without having to build a lot of bad applications first.

I very much enjoyed reading this book and got a lot out of it. To date, I've read about four of the major Ajax titles from various publishers, and this is the best of them so far. Christian Gross uses a very friendly voice and makes tacking the technical concepts behind modern-day web programming with Ajax - often a difficult task to simplify by the writing community - very easy to grasp. But don't think just because Gross slyly defines the relationship of JavaScript, XML and HTTP that this is merely a book for the newbie. He uses some very advanced patterns soon into the book, and bases his fundamental asynchronous calls on one of the better models of safe and reliable cross-browser object instantiation through the use of a simple factory pattern. It's effective programming by way of intelligent design. I appreciated the fact that the patterns described within the book aren't those that are becoming commonplace among blogs, wikis and books, demonstrating the range of Ajax programming on today's web. Gross also mentions the idiosyncrasies of the major browsers in handling things like HTTP headers, caching, output display (or lack thereof), and other things you'll need to know. Perfect examples of these helpful patterns are those used for persistent communications, cache controlling and permutations for multi-device UI rendering. (I still would have liked to see Gross' take on the 'AutoSave' feature that's so copied by early Ajax adopters, but I won't hold it against him.) I also enjoyed the fact that the book kept coming back to REST-style programming, with the capstone chapter being an exhibit of MVC-style applications development on top of REST. Not enough has been published in mainstream print about working with, much less describing, REST systems, so this was another definite plus. He also references several languages in describing patterns and concepts, such as PHP, Python, C# and Java. While it is a bit of a stretch for those of us not using each one of the languages, it does show cross-platform effectiveness. Gross also breaks down the importance of coding object-oriented JavaScript, using prototypes, code reuse and other best practices concepts that may take a few re-reads to fully stick, but will make you a better overall programmer. This is a definite must-have.

I thought the use of design patterns in the book and there use in Ajax is well done and refreshing. I've been a developer for a long time and have seen plenty of garbage code; you won't find that here. The book has many good Ideas and serves as a good best practices on Ajax and Javascript. I enjoy the fact that the Author covers many of the problems a developer may face with Ajax. My Final thoughts is that it was money well spent.