Disclaimer: I received a digital of this book for free from Packt Pub to review it. I’m not receiving any rewards by writing this review, and it contains my fair opinion. Here is the link to buy it.
Nokogiri is one of my favourite gems. I have used it alongside projects since I started developing applications with Ruby, some four years ago. As it is built upon LibXML2, a C library to deal with XML written in C, it has a nice performance and provides a beatiful API to deal with XML (and similar things like HTML). Even it requiring an extra effort to install (you have to compile the gem and install Libxml2 for that), I think it is worth it.
Powers’s book give you a nice overview of the library, what it is, how to install it and some basic usage, including a tutorial that will tell you how to do some page scraping using Nokogiri. It also will show you a summary of the main API methods that you will need to know to get some stuff done.
It is a kind of reading that I enjoy: a short book that goes right into the subject and tells you how to accomplish some task using a new tool, and it also may teach you some API usage that you didn’t know before. As the book name tells you, it is a knowledge shot that will provide you some basic knowledge about this tool, and even if you’re experienced with this library, you may learn a thing or two reading this book.