Chapter 25. W3C DOM Reference

This part of the book is a reference section that documents the interfaces, methods, and properties defined by the W3C Level 1 and Level 2 DOM standards. Intermediate and advanced programmers who are writing for the newest generation of standards-compliant web browsers will use this reference section, in conjunction with the core and client-side JavaScript references in Part III and Part IV. The introduction and sample reference page explain how to use and get the most out of this reference section. There are significant differences between this reference section and the other two, and you should read this introduction carefully so you can fully understand the reference information it contains.

Like the core and client-side references, this reference section is arranged alphabetically. The reference pages for the methods and properties of DOM interfaces are alphabetized by their full names, which include the names of the interfaces that define them. For example, if you want to read about the appendChild( ) method of the Node interface, you would look under "Node.appendChild," not just "appendChild."

To save space in this enlarged fourth edition of the book, properties in this reference section do not have reference pages of their own (all interfaces and methods do have their own reference pages, however). Instead, each property is completely documented in the reference page for the interface that defines it. For example, you can read about the tagName property of the Element interface in the "Element" reference page.

Sometimes you may find that you don't know the name of the interface that defines the method or property you want to look up, or you may not be sure which of the three reference sections to look up a class or interface in. Part VI of this book is a special index designed to help with these situations. Look up the name of a class, interface, method, or property, and it will tell you which reference section to look in and which class to look under in that section. For example, if you look up "Document," it will tell you that both the client-side and DOM reference sections have entries under that name. And if you look up the name "firstChild," it will tell you that firstChild is a property of Node, which you can read about in this DOM reference section.

Once you've found the reference page you're looking for, you shouldn't have much difficulty finding the information you need. Because the DOM standard is intended to work with languages other than JavaScript, however, it was written with typed languages (such as Java and C++) in mind. Although JavaScript is an untyped language, the property and method type information defined by the standard is still quite useful and is included in the reference pages in this section. This means that method and property synopses in this section use a syntax that is more like Java than like JavaScript. What follows is a sample reference page titled "Sample Entry" that demonstrates the structure of each reference page and explains how to interpret the information presented in each section. Even if you are already well familiar with the third edition of this book, take the time to read this page before diving into the DOM reference section.