Dojo: Using the Dojo JavaScript Library to Build AJAX Applications
Author: James E. Harmon
Publisher: Addison Wesley
Pages: 336
ISBN: 978-0132358040
Aimed at: JavaScript programmers
Rating: 3.5
Pros: Simple tutorial introduction to Dojo
Cons: Fails to cover Ajax satisfactorily
Reviewed by: Ian Elliot

The Dojo JavaScript library is an interesting topic and worth finding out about. This particular book might or might not suit depending on what you are looking for by way of explanation. The book is divided into three sections, a tutorial, an almost reference style approach to the Dojo Widgets and finally a more technical look into using Dojo object and methods more directly. The tutorial is probably the most successful section. It provides a very simple introduction to the main Dojo idea, that is the way you can extend HTML tags by turning them into Dojo widgets using the Dojo parser. The explanation is repetitive in the sense that a form is dissected control-by-control in terms of how and why it is converted into Dojo. Any experienced programmer will catch on to the general idea after the first example and then your best choice is to skim read the rest of the section to see if you are missing anything. In the example the issue of server side code is mostly ignored or reference is made to a suitable JSP page. Because of this the Ajax aspects aren't really satisfactory and given the title of the book you might expect more Ajax overall. The second section is a good reference to the standard Dojo widgets including the layout components. This is useful but it never really digs very deep into any of the widgets and concentrates on the core facilities. It's enough to get you started but not of much use if you plan to be creative. The final section is a problem because the book more or less starts over anew with an account of the history and philosophy of Dojo and the wider context. Then when we do get started on the deeper stuff the explanations are spoiled by obvious omissions that make it hard to follow the often-subtle goings on. If you have an idea of how things are supposed to work you can see what is happening but again the treatment doesn't go very far - not much clue as to how to customise the CSS to give widgets a new look, not enough on XML, not enough on creating your on widgets and generally extending Dojo and again the server side is left very vague. My verdict is that there's is a good book, or even two, an introduction and one more advanced, trying to emerge. If you are a complete beginner and want a long introduction to Dojo and its ideas then you might find the first section useful but if you already know JavaScript there are more suitable books.
<Reviewed in VSJ>