le 22 janvier 2013
Unfortunately, it seems this version lacks an entire chapter about web flows. the summary at the end of chapter 8 on Ajax mentions that the next chapter will cover web flows. But chapter 9 covers GORM. I could not find it in the table of content, and my full text search in my kindle version of the book only found indirect references to flows from the section on services.
Still the book is a good one to discover the main features of Grails 2.0 step by step. I find it valuable even for me who bought the previous verion on Grails 1
But For reference you will still need the online documentation.