Very Readable, Lots of Examples
This is a very accessible and friendly book. I found it much more manageable than Joey Lott's Actionscript 3.0 Cookbook. Its objective is to illustrate the most useful "design patterns"--i.e., ways of approaching and outlining your project. The examples themselves can serve as reusable templates for your own projects, and that's the main point of the book.
excellent concise info on AS3
I realize the book title (and the focus and organization) is about design patterns, but I thought it was worth adding the fact that--for me at least--it's the one book I keep coming back to for great lucent coverage of really key AS3 concepts including event dispatching (and using IEventDispatcher instead). I mean, Colin's Essential AS3 is one to turn to for definitive answers on sub-atomic (and important) details... but I still keep coming back to Danny and Joey's book because it's so direct and to the point. To really learn a subject you need more than a book--but to go back over things... to get a good skeleton starter script (which doesn't have extra baggage)... and for brief clear explanations, this book really does it. It's by no means a dated book either. I just think some people might pass over this book because the title makes it sound like it just covers design patterns when, in fact, it's just a great AS3 book.
Good Introduction to Design Patterns
If you are interested in improving your code to be more maintainable, flexible and gaining a better understanding of Object Oriented Programming (OOP) this is a good book to have. The core concepts are explained in readable language and the code examples are for the most part well-written.
I did notice one criticism of another reviewer is that the book did not address Flex UI components or MXML. Flex is certainly beyond the scope of this book and there are many excellent books on Flex 2+ that will better explain the concepts of programming in Flex. This book is about ActionScript 3 and so it mainly addresses the classes available in the flash package. That does not mean that you cannot apply the concepts from this book to a Flex application however Cairngorm and PureMVC are the patterns most Flex developers gravitate towards and so they would be a better starting point for someone interested in that development platform. For those patterns a developer would likely find the internet to be the best resource for tutorials and information however both of those design patterns are based on core concepts explained in detail in this book so it can give you greater understanding and make the learning process easier.
Even if Flex is your primary area of interest this book can help with understanding many of the underlying core concepts of programming in ActionScript 3 and given the right understanding you can create a Flex application with little or no MXML.
The section on events is worth purchasing the book. It is well-written and is one of the better if not best explanations on the subject as has been pointed out in other reviews.
Pretty Good for a Re-hash
This book served really well as a review to some of the GOF patterns. I already understood the patterns covered, looking at the Actionscript implementations was still somewhat helpful.
I bought the book for its coverage of Actionscript events, which is really the key to creating great apps with Actionscript and Flex (WARNING: all of the examples assume you're building Flash applications, which are similar but not identical to Flex apps). And for its coverage of E4X, Actionscript 3's new XML format. Those two chapters are gems, and I wish I could have bought them in pamphlet form.
Great Book!
Although written specifically for ActionScript this book really helped me further my understanding of design patterns and how to apply them to all my software development projects. Additionally, the the last few chapters cover some advanced ActionScript topics like E4X. Recommended for any experienced developer interested in design patterns.