One of the challenges of writing a printed book about new technology like App Engine is keeping up with the changes. Every month, the App Engine team releases new features, and each new feature is a decision that has to be made for the book. Even small features, like the ability to query for just the keys of entities instead of full entity objects, can change the landscape of best practices enough to ripple through several chapters. Some features, like the Task Queue service introduced at Google I/O this year, are worthy of new chapters of their own.
Then there's the stuff coming down the pipe. This book must at some point be frozen and replicated in a permanent form, and not only do we know that new features could be launched any day now (which is inevitable), but we know what those features are and how the book ought to change to accommodate them. Drawing the line is difficult but necessary.
So the strategy for the book is to emphasize concepts, to tell the stories behind the core designs of the platform, and illustrate them with working code samples. Though the story of App Engine is still being written, there is plenty to say about the state of the world today, and what it might be like in the future. I'm betting important parts of that story can be told without itemizing every feature of the platform, and still be useful to developers.
We're shooting for a publication date of November 2009, and to do that, we'll be pushing chunks of new text into the Rough Cuts draft as quickly as we can over the next couple of months. You can help! Is there a subject you want to see covered in the book, or something you absolutely can't live without? Would you be disappointed if there wasn't a chapter on the Images service? Would you prefer a discussion of performance testing to a discussion of every feature? Are Django, GWT, Grails, JRuby, Google Apps, the Secure Data Connector, GData, Android or Google Wave the center of your life? Let me know! Not everything will make it into the 1st edition, but as we fit the outline to the deadline, you can make a difference.
Many thanks to all of the Rough Cuts subscribers that have submitted feedback so far. Keep it up!
Oh, and check out a sneak peak of the new cover on the site. The animal is a waterbuck. (Uh, no "moving target" pun intended.)