Actionscript Cookbook

19.15. Searching XML

Problem

You want to search an XML object for nodes based on keywords and other criteria such as node hierarchy.

Solution

Use the third-party XPath class from XFactorStudio.com.

Discussion

Thus far in this chapter you’ve read recipes on how to work with XML objects using the DOM, or Document Object Model. This means that if you want to locate a particular node in the XML tree, you need to know the relationship of that node to the whole (i.e., first child, next sibling, etc.). However, when you want a more flexible way of looking for nodes, the DOM can become tedious.

XPath is a language that allows you a much more intuitive and flexible way to find nodes within an XML object. XPath is a W3C standard (see http://www.w3c.org/TR/xpath) that is supported on many platforms, but it is not natively supported in Flash. However, Neeld Tanksley of XFactorStudio.com has created an ActionScript XPath class that you can download from http://www.xfactorstudio.com/projects/XPath/index.php. You should download the .zip file and extract all the .as files into your Flash Include directory (make sure they are extracted into the Include directory, and not into subdirectories).

Once you have downloaded and installed the custom XPath class, you can include it in your Flash movies and begin using XPath to work with XML, as follows:

#include "XPath.as"

XPath uses path expressions to denote the node or nodes you want to find. For example, if the root node in your XML object is named books ...