Is the book worth buying?
If it's the one by Kieren Diment and Matt Trout, then hell yes.
I got it about a month ago and tore through it.
I haven't had a chance to write something in it but just reading through it gave me a better grasp of not only Catalyst but:
- MVC frameworks
- frameworks that dispatch
- writing better code
I've been doing Perl since 1996 (but mostly as a sysadmin) so I'm rather handy with it but this gave some nice examples of Test Driven Development (in their interpretation of it).
One of the better Perl books out there.
Seeing as this book gets recommended everywhere else, I thought I'd offer a contrary opinion - as an existing user of Catalyst, DBIx::Class, etc, I didn't think very much of the book. It's ok (and obviously the authors know what they're talking about!) but it seemed cluttered, and several things that I've been stuck on and hoped would be discussed in the book aren't mentioned at all. Important bits like the dispatch order diagram are tucked away well into the book (and squashed onto one page), and it has the same problem as the Catalyst docs - various features are mentioned in passing without being given focus themselves.
I blog about Perl, but also write alot of Perl programs