Having already seen many of his videocasts after listening to the Grailspodcast, I consider Scott to be a like a Vincent Van Gogh of the tech world. A Master.
I've read Groovy in Action, a more in depth reference (Groovy in Action 2 will be out later this year too) and Programming Groovy, both fantastic Groovy books.
But I actually like this one the best. It's definitely the book I'd turn to first when I need an example to jog my memory. Worthy of the pragmatic badge as always.
It's an awesome read. Great if you want to learn Groovy in a hurry and like learning from examples. The book distills things into more clear, concise memorable chunks.
It's well cross-referenced and the format make it easy to read in a non-linear fashion if you want to.
The book consists of twelve chapters:
--2 Getting Started: Installing & Running Groovy, Groovy Shell/Console, IDE support. There is good advice on Mac/Unix/Windows installs.
--- The book only covers binary rather than source versions. It advises the use symlinks for Unix & derivatives, which is best way to go.
--3 New to Groovy: covers syntax - bringing the Java developer up to speed
--4 Java and Groovy Integration - includes good discussion on joint compilation
--5 Groovy from the command line - This is a superb chapter - material not covered in a lot of the books.
--6 File Tricks - Listing Files/Directories, Writing to files, Moving, Renaming files, AntBuilder etc
--7 Parsing XML : XMLParser, XML Slurper comparison
--8 Writing XML : MarkupBuilder & StreamingMarkupBuilder
--9 WebServices : Another fantastic chapter : Takes you through HTTP, SOAP, REST, XML-RPC, Atom/RSS, Parsing search engine results as XML
-10 Metaprogramming : Really good chapter. Good for getting your head around Categories, Expandos & ExpandoMetaClass (Venkat's book goes into more detail here - but this is a good second)
-11 Working with Grails : A whirlwind tour of Grails. - A similar approach was taken in Groovy in Action at the end..
--- Scott informed me he is actually working on a second edition of a Grails PDF book with Jason Rudolph for InfoQ too that is in the finals stages of production. So expect this to be another great resource.
-12 Grails & Web Services : Returning XML, JSON, Excel. Setting up RSS (for podcasts) & Atom Feeds - Pretty good. But worst chapter of book for me. Didn't like the way some of the code was laid out.
--- I prefer to see the whole thing at once, not snippets with bits missing, then incrementally expanded later.
There are a few errors:
-P42 A size that should have returned 4 not 5 as a result.
-P79 Space missing between words.
P107 Space missing between words.
P215 Mentions customising scaffolding to facilitate adding a timestamp to a record in Grails - which Grails automatically does by adding a couple of appropriately named properties. Google on "Grails GORM Events".
P224 Graeme Rocher confirmed Grails now supports M-M relationships in the scaffolding. Mike Kimsal, the guy behind Groovymag blogged about a solution a while back too.
P236 There is a paragraph repeated twice.
Scott also writes for IBM Developerworks (Practically Groovy & Mastering Grails series).