The Definitive Guide to Catalyst: Writing Extendable, Scalable and Maintainable Perl-Based Web Applications (Expert's Voice in Web Development) [Paperback]

Kieren Diment (Author), Matthew Trout (Author)

Book Description

ISBN-10: 1430223650 | ISBN-13: 978-1430223658 | Publication Date: July 9, 2009 | Edition: 1

Perl is the language most favored by systems administrators, who are often given the task of setting up and maintaining an organization's website. Catalyst is to Perl what Rails is to Ruby. This book, by two well known members of the Catalyst community, shows Perl users how to write web applications using a modern framework based on their language of choice.

Editorial Reviews

About the Author

Kieren Diment is social researcher in the School of Management and Marketing, University of Wollongong Australia where he uses Catalyst for the collection analysis and presentation of research data. He has taken the lead in a significant portion of the Catalyst documentation including the Catalyst Advent Calendar in 2006 and 2007. His focus has been on ensuring a culture of documentation by example in the project, and ensuring that instructional documentation points to working example code wherever possible.

Matt S Trout is Technical Director of Shadowcat Systems Limited, an Open Source focused consultancy based in Lancaster, England, who specialize in helping clients with design, development and deployment of Catalyst and DBIx: Class based applications. He is the second longest standing member of the Catalyst core team and focuses on architecture, program management and ease of installation and deployment of Catalyst and Catalyst-based applications.

Product Details

• Paperback: 332 pages
• Publisher: Apress; 1 edition (July 9, 2009)
• Language: English
• ISBN-10: 1430223650
• ISBN-13: 978-1430223658
• Product Dimensions: 10.1 x 7.5 x 0.8 inches
• Shipping Weight: 1.4 pounds (View shipping rates and policies)
• Average Customer Review: 4.1 out of 5 stars  See all reviews (8 customer reviews)
• Amazon Best Sellers Rank: #727,278 in Books (See Top 100 in Books)

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13 of 14 people found the following review helpful:

5.0 out of 5 stars Definitive Guide to Modern Perl Development, September 12, 2009

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David Cross "davorg" (London, UK) - See all my reviews
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This review is from: The Definitive Guide to Catalyst: Writing Extendable, Scalable and Maintainable Perl-Based Web Applications (Expert's Voice in Web Development) (Paperback)

Catalyst is one of the most interesting projects to come out of the Perl community in the last few years. Originating as a fork of the Maypole web framework, Catalyst has grown into the de facto standard for building web application using Perl. Its power and flexibility make it a great choice for many web-based projects.

But often great power and flexibility goes hand in hand with complexity. I've used Catalyst in simple ways on a couple of projects but I had always suspected that I wasn't getting everything that I could out of the software. What I really needed was a good book that explained the best way to get the most out of Catalyst. With this book I think I've got what I was looking for. The book is written by two core members of the Catalyst team. They obviously know exactly what they are talking about and lead the reader confidently through the complexities of Catalyst.

Catalyst, like other well-known web frameworks like Django or Ruby on Rails, uses the Model-View-Controller (MVC) pattern. This book doesn't assume that you are already familiar with this pattern and chapter 1 explains the underlying concepts in some detail. It also takes time to compare the Catalyst way of doing things with CGI applications and to compare Catalyst itself with other Perl frameworks like CGI::Application and Jifty.

Chapter 2 gets you started by discussing how to install Catalyst. This can be difficult as Catalyst requires a large number of other Perl libraries to be installed, and this section explains the easiest way to do with by using Perl's built-in features. This chapter also contains an introduction to Object Oriented programming in Perl using Moose. This is indicative of the authors' dedication to promoting modern Perl best practices and it's a topic I shall return to later.

Chapter 3 moves on to writing a simple application in Catalyst. Once again the authors' interest in best practices is evident as the application is not only written using Moose, but also has a comprehensive test suite. The application built in this chapter is pretty simple and some corners are cut in order to get something written as quickly as possible. These shortcomings are addressed at some length in chapter 4 where the application is rewritten in order to make it easier to maintain and extend.

Having written an application using Catalyst's built-in development web server, you will next need to deploy it. Chapter 5 takes a detailed look at your options for deploying Catalyst applications on a range of popular web servers.

The next two chapters look at two important parts of the Catalyst framework. Chapter 6 looks at database models, concentrating on the use of DBIx::Class - the most popular database abstraction layer used with Catalyst (and, indeed, with Perl itself). Chapter 7 looks at Catalyst's dispatch model - how a Catalyst application decides which of its method need to be called to respond to a given request. In earlier chapters I felt that some of the details of the dispatch model had been rather skimmed over, but this chapter more than makes up for that.

Chapter 8 looks at another vital part of modern web applications - that of authentication and authorisation. Catalyst has a number of plugins which makes these activities as easy as I have seen in any web framework. Chapter 9 looks at web services - both how to consume external services in your application and how to make a web service API available to users of your application. The latter becomes ridiculously easy with Catalyst.

If there is something that you don't think that Catalyst can do for you, then you'll find Chapter 10 useful as it examines a number of ways to extend Catalyst's behaviour. There are already dozens of add-ons and plugins available for Catalyst, but this chapter gives clear instructions on how to add to this collection.

Chapter 11 is a useful cookbook of recipes that will help you be more efficient in your use of Catalyst. Some of them solve common problems that you'll come across when writing applications but another, more interesting, section talks about ways to just become a more efficient developer. Many of these (for example, using Perl::Tidy and Perl::Critic) are general development techniques that aren't specific to Catalyst. Finally, chapter 13 looks at Reaction, which is a higher level framework which is based on Catalyst.

One of the problems with writing books about a project like Catalyst is that in the early days of a project, things can change very quickly. Sometimes so quickly that a book is out of date before it is published. I think that Catalyst has now settled down from the intense development cycles of the last few years, so this book will be relevant to Catalyst users for quite some time.

I'm convinced that Catalyst will be a useful tool to add to my collection and that this book will be very useful while I'm getting myself up to speed with writing applications with Catalyst. It's also very likely to be useful as a reference long after I'm familiar with how Catalyst works. If you're looking at writing a web application and are looking for a framework to use then this book should convince you to add Catalyst to the list of possibilities that you consider.

If you're a Catalyst user or a potential Catalyst user then you don't really need me to tell me that this book will be well worth buying. But there's another group of people who I would highly recommend this book to - and that's everyone who is currently programming in Perl, even if you never go near web developement or Catalyst. The reason for this seemeingly bizarre recommendation is easy to explain. Perl has been changing a lot over the last five years. The basic syntax remains (mostly) the same, but a number of new tools have been introduced that every Perl programmers should be looking at. Perl books don't get published as frequently as they used to and this is (as far as I know) the only book which emphasises new Perl tools like Moose and DBIx::Class. There is a whole new Perl movement out there called Modern (or Enlightened) Perl and this book is the best introduction to this movement currently in print.

The application development methods discussed by the authors of this book are the ones which will define good Perl development practice in the coming years. If you have any interest in how you should be developing Perl applications then you should be buying this book.

9 of 9 people found the following review helpful:

5.0 out of 5 stars Catalyst - Now with more awesome!, July 22, 2009

By 

Devin J. Austin "Catalyst Hacker" (Denver, Colorado) - See all my reviews
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This review is from: The Definitive Guide to Catalyst: Writing Extendable, Scalable and Maintainable Perl-Based Web Applications (Expert's Voice in Web Development) (Paperback)

I'm the maintainer and refactor-er of the Catalyst::Helper namespace. That said, I should know a great deal about Catalyst. With THAT said, after even my first skim of this book, I picked up some great tips that I had not thought of or stumbled upon before. The collaboration between the authors and the attitude of "no less than excellent" each one of them has led to this being an extremely in depth, informative, and must-have resource for novice, experienced and non-Catalyst developers alike. Not only will you learn how to use the premier Perl web framework, but you will improve your Perl hacking skills as well.

From your first line of Catalyst, to deployment, to maintenance, you will learn how to create Catalyst applications the right way, the scalable way, and the easy way.

Kudos to each and everyone one of the authors, and the Catalyst community for making this such a great book.

18 of 22 people found the following review helpful:

2.0 out of 5 stars Incremental to the POD documentation, but disappointing., October 12, 2009

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Fake Name (Seattle, WA USA) - See all my reviews

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This review is from: The Definitive Guide to Catalyst: Writing Extendable, Scalable and Maintainable Perl-Based Web Applications (Expert's Voice in Web Development) (Paperback)

I've used Perl for about ten years, and have experience with all of the "pre-Catalyst" frameworks and helpers (from CGI.pm to CGI::Application to dalliances with writing my own and trying Jifty). I've also used Rails and read several books on it (most of which are disappointments).

Unfortunately, I found this guide a disappointment as well. Most of the book seems to be structured around a few "examples," the largest of which is a translation app from English into "Lolcat." The problem with such an app as an example is that it could readily be done in a dead-simple, several-line CGI script (hell, even a one-liner could probably do it), so it requires a certain suspension of disbelief that one should be using stashes, chained dispatch methods, templates, and the like. Why not a normal CRUD type app as an example? Boring, yes, but to-the-point and more likely to be illustrative of the tools and their best applications.

The conversational "flow" of the book is distracting, as well. I understand that a more tabular or outlined form for making specific information easier to find could render it hard to read "straight through" as a book. But the sheer volume of information, and diversity of scenarios, make it unlikely that anyone will read it straight through and make equal use of all parts. Far better to organize the content more rigorously by function -- for example, the best and best-structured chapter by far is the chapter on dispatch (it gets to borrow for its prose structure from the flow chart on page 168. Less in-depth meanderings into such adjuncts as DBIx::Class and Moose, but more on how (if at all) such outside modules must interface / play nice with the Catalyst core. A chapter on errors. A chapter on logging. A chapter on templating.

The index is a mess and lazily put together. Under "log", only one entry: "Logging, in Catalyst, 7." (Are you serious? who wrote that index entry? Logging, comma, IN CATALYST?!? SERIOUSLY??) For "error:" "error handling code, changing to output errors to the log, 104-105." Nothing for "exception" (fair enough, as Perl properly has none), but under Perl's equivalent, "die:" "die, using for error handling, 156." WTF? Finding these three sections shouldn't be an Easter-egg hunt. WTF would be wrong with:

error
using "die" ... 156
logging ... 104-105
see also *log*

log ... 7
errors ... 104-105


I'm rooting for Matt & co., and I'm a fan of Catalyst. But this book needs a reworking for its next edition, and it needs an editor (the typography, too, is underwhelming). It's not that the team that wrote this isn't smart enough, or that they don't know the subject well enough. It's merely that they need to structure, structure, structure, and clarify, clarify, clarify. Looking forward to second edition, guys.