jQuery in Action

Written by a jQuery contributor and a jQuery evangelist “jQuery in Action“ promises a quick introduction to the jQuery JavaScript library.

Prefaced with a very positive foreword from John Resig, the jQuery creator, and after a short introduction about the authors, the first chapter starts. In this first chapter the jQuery library is introduced and a few of the most important aspects are explained. Apart from the jQuery philosophy of Unobstrusive JavaScript the combination with other libraries such as Prototype is described.

Fortunately the authors do not give a general introduction to JavaScript as many other books do but start immediately with explaining jQuery. Advanced and important JavaScript concepts, which some developers may not know, are explained in an extensive appendix. This way even advanced developers can dive right in.

While the first chapter barely mentioned the jQuery selectors, chapter two is focused exclusively on these. Through a lot of examples the authors not only cover the basic CSS selectors but also the advanced jQuery selectors. An interesting element which is used in chapter two for the first time are so called lab pages. As the book does not come with a CD you have to download these first, but then you have an interactive webpage with examples for every covered topic. This allows one to practice immediately what was covered before.

All chapters follow the same structure, at the beginning of each chapter there is a short introduction and motivation to the following topics. Then, at the end of each chapter, follows a short summary which includes the most important points. The great advantage of this structure is possibility to read chapters individually.

The third chapter covers operations on groups of selected objects and the modification of their attributes. When it is appropriate the authors give examples of browser incompatibilities and then show how elegant jQuery solves these problems by providing a unique an portable interface to these functions.

Invoking and intercepting events is one of the most important scenarios for JavaScript and therefore the corresponding chapter four is one of the longest in the book (42 pages). Beginning with the DOM Level 0 Event Model and Level 2 Model the book goes on and explains in detail the jQuery object model. At the end there is again a lab page to demonstrate the possibilities.

In this chapter (and in some others) the authors use tables to present a complete overview of options for a specific method. While this is great to get a quick overview of the possible combinations, these tables better would have been placed at the end of the book to allow the usage as a general reference.

Chapter six covers often used helper functions, for example a way to determine the visiting browser is presented.

The seventh chapter talks about one of the most important points of the jQuery success: the powerful and easy to use plugin architecture. As the underlying mechanism is very simple and easy to understand, the chapter is relatively short but the authors provide information about important and popular plugins in the last chapter. As no book about JavaScript or a JS library is complete without a part about AJAX, the remaining part of the book gives an overview about possibilities to handle AJAX requests with jQuery. Nearly every possible combination, starting with simply loading content from a static html file to completely controlled http requests is explained and there is a short example code provided for every possibility.

Overall I liked the book very much. The jQuery library is covered in a complete and understandable way. jQuery in Action is a compact book for a compact library, which I would like to recommend to every web developer who is thinking about using jQuery in his or her projects.