User Guide

The E4X approach to XML processing 313

Since many server-side applications use XML to structure data, you can use the XML classes

in ActionScript to create sophisticated rich Internet applications, such as those that connect to

web services. A web service is a means to connect applications—for example, an Adobe Flash

Player 9 application and an application on a web server)—through a common standard such

as the Simple Object Access Protocol (SOAP).

The E4X approach to XML processing

The ECMAScript for XML specification defines a set of classes and functionality for working

with XML data. These classes and functionality are known collectively as E4X. ActionScript

3.0 includes the following E4X classes: XML, XMLList, QName, and Namespace.

The methods, properties, and operators of the E4X classes are designed with the following

goals:

■ Simplicity—Where possible, E4X makes it easier to write and understand code for

working with XML data.

■ Consistency—The methods and reasoning behind E4X are internally consistent and

consistent with other parts of ActionScript.

■ Familiarity—You manipulate XML data with well-known operators, such as the dot (.)

operator.

Here is an example of manipulating data with E4X:

var myXML:XML =

<order>

<menuName>burger</menuName>

</item>

<menuName>fries</menuName>

</item>

</order>

NOTE

There was an XML class in ActionScript 2.0. In ActionScript 3.0 it has been renamed

XMLDocument, so that it does not conflict with the ActionScript 3.0 XML class that is

part of E4X. In ActionScript 3.0, the legacy classes—XMLDocument, XMLNode,

XMLParser, and XMLTag—are included in the flash.xml package primarily for legacy

support. The new E4X classes are core classes; you need not import a package to use

them. This chapter does not go into detail on the legacy ActionScript 2.0 XML classes.

For details on these, see the flash.xml package in the ActionScript 3.0 Language

Reference.