About the Recipes

It's helpful for a reader to know up front what biases an author has on the book's subject. To carry the cookbook metaphor too far, just as a culinary chef has identifiable procedures and seasonings, so do I format my code in a particular way and employ programming styles that I have adopted over the years.

More important than scripting style, however, are the implementation threads that weave their way throughout the code examples. Because these examples may serve as models for your own development, they are written for maximum clarity to make it easy (I hope) for you to follow the execution logic. Names assigned to variables, functions, objects, and the like are meant to convey their purpose within the context of the example. One of the goals of coding is that the operation of a program should be self-evident to someone else reading the code, even if that "someone else" is the programmer who revisits the code six months later to fix a bug or add a feature. There's no sense in being cryptically clever if no one can understand what you mean by assigning some value to a variable named x.

This book unabashedly favors the W3C DOM way of addressing document objects. You can use this format to reference element objects in browsers starting with Microsoft Internet Explorer 5 and Netscape 6, which means that the vast majority of browsers in use today support this standard. Where IE does not support the standard (as in handling events), all recipes here include efficient cross-browser implementations. You won't find too much in the way of IE-only solutions, especially if they would cover only the Windows version of IE.

At the same time, this book acknowledges that you may need to support users who do not have W3C DOM-empowered browsers. You will find that substantial attention is paid to making even advanced DHTML scripts coexist gracefully in an old or nonscriptable browser. This is particularly important if you wish your pages to serve visitors with accessibility challenges (such as vision or physical impairments) or pocket computers containing underpowered browsers.

One credo dominates the recipes throughout this book: scripting must add value to static content on the page. Don't look to this book for scripts that cycle background colors to nauseate visitors or make elements bounce around the page while singing Happy Birthday. You may be able to figure out how do those horrible things from what you learn in this book, but that's your business. The examples here, while perhaps conservative, are intended to solve real-world problems that scripters and developers face in professional-quality applications.

The scripting techniques and syntax you see throughout this book are designed for maximum forward compatibility. It's difficult to predict the future of any technology, but the W3C DOM and ECMAScript standards, as implemented in today's latest browsers, are the most stable platforms on which to build client-side applications since client-side scripting began. With a bit of code added here and there to degrade gracefully in older browsers, your applications should be running fine well into the future.