Design Patterns in Ruby (Addison-Wesley Professional Ruby Series) (Hardcover)

by Russ Olsen (Author) "It's funny, but design patterns always remind me of a certain grocery store..." (more)
Key Phrases: template method, convention over configuration, creating custom objects, Getting Started, Picking the Right Class, Assembling Your System (more...)

Editorial Reviews

Product Description

Praise for Design Patterns in Ruby

"Design Patterns in Ruby documents smart ways to resolve many problems that Ruby developers commonly encounter. Russ Olsen has done a great job of selecting classic patterns and augmenting these with newer patterns that have special relevance for Ruby. He clearly explains each idea, making a wealth of experience available to Ruby developers for their own daily work."

—Steve Metsker, Managing Consultant with Dominion Digital, Inc.

"This book provides a great demonstration of the key 'Gang of Four' design patterns without resorting to overly technical explanations. Written in a precise, yet almost informal style, this book covers enough ground that even those without prior exposure to design patterns will soon feel confident applying them using Ruby. Olsen has done a great job to make a book about a classically 'dry' subject into such an engaging and even occasionally humorous read."

—Peter Cooper

"This book renewed my interest in understanding patterns after a decade of good intentions. Russ picked the most useful patterns for Ruby and introduced them in a straightforward and logical manner, going beyond the GoF's patterns. This book has improved my use of Ruby, and encouraged me to blow off the dust covering the GoF book."

—Mike Stok

"Design Patterns in Ruby is a great way for programmers from statically typed objectoriented languages to learn how design patterns appear in a more dynamic, flexible language like Ruby."

—Rob Sanheim, Ruby Ninja, Relevance

Most design pattern books are based on C++ and Java. But Ruby is different—and the language's unique qualities make design patterns easier to implement and use. In this book, Russ Olsen demonstrates how to combine Ruby's power and elegance with patterns, and write more sophisticated, effective software with far fewer lines of code.

After reviewing the history, concepts, and goals of design patterns, Olsen offers a quick tour of the Ruby language—enough to allow any experienced software developer to immediately utilize patterns with Ruby. The book especially calls attention to Ruby features that simplify the use of patterns, including dynamic typing, code closures, and "mixins" for easier code reuse.

Fourteen of the classic "Gang of Four" patterns are considered from the Ruby point of view, explaining what problems each pattern solves, discussing whether traditional implementations make sense in the Ruby environment, and introducing Ruby-specific improvements. You'll discover opportunities to implement patterns in just one or two lines of code, instead of the endlessly repeated boilerplate that conventional languages often require.

Design Patterns in Ruby also identifies innovative new patterns that have emerged from the Ruby community. These include ways to create custom objects with metaprogramming, as well as the ambitious Rails-based "Convention Over Configuration" pattern, designed to help integrate entire applications and frameworks.

Engaging, practical, and accessible, Design Patterns in Ruby will help you build better software while making your Ruby programming experience more rewarding.

About the Author

Russ Olsen has been building software for more than twenty-five years. He has led projects through several generations of programming technologies, from FORTRAN to C to C++ to Java, and now Ruby. He has been using and teaching Ruby since 2002. Olsen writes the popular technology blog Technology As If People Mattered (http://www.russolsen.com).

See all Editorial Reviews

Product Details

• Hardcover: 384 pages
• Publisher: Addison-Wesley Professional; 1 edition (December 20, 2007)
• Language: English
• ISBN-10: 0321490452
• ISBN-13: 978-0321490452
• Product Dimensions: 9.3 x 7.1 x 0.9 inches
• Shipping Weight: 1.6 pounds (View shipping rates and policies)
• Average Customer Review: 4.7 out of 5 stars See all reviews (17 customer reviews)
• Amazon.com Sales Rank: #282,722 in Books (See Bestsellers in Books)

Customer Reviews

Most Helpful Customer Reviews

18 of 18 people found the following review helpful:

5.0 out of 5 stars One of the best Ruby books ever, February 7, 2008

By	Ricardo Dapaz "IT Consultant" (Perth, WA Australia) - See all my reviews (REAL NAME)

Warning: This book is not a reference!!!
Well, it could be but it probably won't need to be as each concept is explained so well that you will remember when to apply this pattern or that pattern for every situation. The author is engaging and funny making this quite a book turner for a technical book. I almost read half the book on the 2 hour commuter flight between Perth and Karatha. Every chapter starts with a little anectode about the author's past life events and how these are related to the use of a particular pattern. The examples are well thought out and the author also discusses Ruby specific implementation details as well as providing valuable insights into how each pattern is used in the existing Ruby codebase.

I come from a Python/C/C++/Java background and have been tinkering around with ruby for a while but without really "getting it" and understanding what the fuss was about. The same could be said about design patterns. After reading this book I have finally grokked, not only Ruby but the value and power of design patterns. I can now say that I truly understand exactly why there is such a hype about Ruby. The whole method_missing thing, singleton support, ability to clone classes, etc. This language really represents the future of programming - today - and this book delivers on its intent.

This is simply one of the best technical books that I have read in a long time and I thoroughly recommend it, especially for an intermediate Ruby programmer and even those who know OO concepts and principles but may be new to Ruby.

12 of 12 people found the following review helpful:

4.0 out of 5 stars Surprisingly Useful, January 13, 2008

By	David Hume (Seattle) - See all my reviews

Design Patterns in Ruby delivers what the title suggests. It covers 14 of the patterns from the original 'gang of four' patterns book, and introduces 3 additional patterns that are in widespread use in the ruby world. The book is engagingly and clearly written. More importantly, it illustrates each pattern with an extended example, often showing alternative designs. Each chapter concludes with notes on how the pattern should and should not be used, and lists at least one example of the pattern in actual code.

I had low expectations for this book, but I was very pleasantly surprised. Like many programmers I tend to think of the gang-of-four patterns as being primarily useful in languages that are semantically limited, such as Java and C++. In dynamic languages like ruby and Scheme, design patterns seem to come more naturally, and are easily expressible in the language, and so tend to disappear. But Olsen convinced me that there really are non-trivial uses for most of the patterns that he covered.

In case you're wondering, the patterns are:

* Template
* Strategy
* Observer
* Composite
* Iterator
* Command
* Adapter
* Proxy
* Decorator
* Singleton
* Factory, Abstract Factory
* Builder
* Interpreter
* Domain Specific Language
* Meta-Programming
* Convention over Configuration

11 of 11 people found the following review helpful:

4.0 out of 5 stars Valuable Resource, January 13, 2008

By	David L. Richards (Portland, OR USA) - See all my reviews (REAL NAME)

I just finished this book, cover to cover. I rarely read books like this all the way through. I scan them and keep them around in case they help me out of a jam. But this book is different. It is formative in the sense that the original Gang of Four (GoF) book on patterns was formative: it asks us to think about our problems in fresh ways.

One important part of this book, however, stresses the use and overuse of these patterns. Olsen emphasizes that this isn't a competition to use all the patterns. Whoever has the most patterns doesn't necessarily win. Whoever uses code gracefully and simply does. It reminds me of the talk by Marcel Molina Jr. at RubyConf 07, speaking about what makes code beautiful. It's the proportion, integrity, and clarity that makes beautiful code. I.e., we keep the code as simple as we can, keep it focused on the problem at hand, and we do it clearly. This book warns against misuse or abuse of patterns as much as it teaches the patterns themselves.

Another thing that I found very useful about this book is it suggests simpler ways for my existing code. This tells me that, though I was happy with the function of what I could do once, the form can improve that it doesn't fall apart in the face of future iterations.

Finally, I enjoy how each chapter evolves. We start with a rigorous interpretation of the GoF patterns, then Olsen introduces simpler ways to implement the ideas that take into account Ruby's available economies. So, we write simpler code, understand the tradoffs of the various alternative implementation methods, and understand the patterns themselves more concretely.

Other than the occasional loose editing that come up from time to time, I really wouldn't change what was written. I would have enjoyed more chapters on other patterns, even some that are outside the scope of the GoF book. But that's just a reflection of my respect for Olsen's love of the material and skill in teaching it.

If you're picking up Ruby to write Rails code, maybe start with the Agile Development book. If you've finished your first personal Rails project, or you have other uses of Ruby in mind, I'd suggest this as the next book you pick up. After this book, I'd next suggest The Ruby Way by Hal Fulton. That's probably the fastest way to pick up Ruby in a professional context.