It has been a while I got hold of new book on Play framework from Packt publications - Play Framework Cookbook. I just completed reading this book.
Play online documentation is itself awesome - explaining the basics and leaving the readers to explore complex features on these basics. This book complements the online documentation and digs deep on some of the great features of the framework - providing practical techniques with source code.
The book is written by Alexander Reelsen. 


Pre-requisites:
This book is intended for experienced Play users -  not the beginners. By experienced I mean, users who understand the basics, high level architecture of Play and who have worked on few examples. There is very less introductory stuff. 

Review:
The book covers the Play 1.2 version, whereas the current online version available online is 1.2.3. One of the technical review member is none other - Guillaume Bort - the creator of the Play framework. There is no question of technicalities and correctness of the code examples.
There are 7 chapters with an Appendix covering about 60 recipes.

The most useful chapters that I found where:
1. Leveraging Modules - This chapter covers dependency injection with Spring and Guice. There is a recipe of using MongoDB module which I found useful. The recipes are useful and gives a good insight into how modules can provide powerful extensions to Play’s core functionality.
2. Introduction to Writing Modules - This is another useful chapter - which is not easily found on the web. When the project size increases, it is best to split into modules and manage the complexity. This covers Play plugins, understanding events, managing module dependencies.
3. Running in Production - This is an very important chapter which will be most useful for any project team. Almost all the recipes presented in this chapter like - Test automation,  SSL for certain controllers, running jobs in distributed environment are very useful and clearly explained.

Criticisms
1.  The code examples span multiple pages and not very well formatted.  This is nothing to do with the content but with more of formatting and presenting. Just look at any O'reilly book, their editors do an awesome job
2. Few recipes lack good explanation - it could have been improved - For e.g. - "Understanding events" in the "Introduction to Writing Modules"
3. The reader can make out that English is not the first language of the Author. This is some room for improvement in this area.

Conclusion: It is definitely a very useful book for teams who have already started using the framework. As I said earlier - it complements the online documentation. It is a good buy - worth the investment.

Disclosure: I was provided with an eBook copy of the Play Framework Cookbook by Packt Publishing for the purposes of this review.