IN THIS CHAPTER
Understanding XML Structure
Creating an XML Object
Using Variables in XML
Loading External XML Documents
Sending to and Loading from a Server
An XML-Based Navigation System
XML, which stands for Extensible Markup Language, is a structured, text-based file format for storing and exchanging data. If you’ve seen HTML before, XML will look familiar. Like HTML, XML is a tag-based language. However, it was designed to organize data, rather than lay out a web page. Instead of a large collection of tags that define the language (as found in HTML), XML is wide open. It starts with only a handful of preexisting tags that serve very basic purposes. This freedom allows you to structure data in a way that’s most efficient for your needs.
In the past, traversing and working with XML within ActionScript has not been the most pleasant or efficient of experiences. Fortunately, E4X (which stands for ECMAScript for XML), is a part of ActionScript 3.0. E4X is the current standard for reading and writing XML documents and is maintained by the European Computer Manufacturers Association. It greatly reduces the amount of code and hoop-jumping required to communicate with XML. It allows you to treat XML objects like any other object with familiar dot syntax, and provides additional shortcuts for traversing XML data. You can use ActionScript’s E4X implementation to create XML inside a class or the Flash timeline or, more commonly, load ...