Web Services, Part VI: XML Parsing and Loading from JavaScript

In this column we continue our series on Web services. In Part I, we introduced you to this hot topic. In Part II, we showed you how to call Web services. In Part III, we presented the WebService behavior and its four supported methods. In Part IV, we continued our coverage of the WebService behavior by describing its objects and properties. In Part V, we dove into XML and XSLT. In this column, we connect back to JavaScript. Handling XML from JavaScript is critical for developing and consuming Web services. In this column, we start a miniseries on how to load and manipulate XML files from JavaScript.

When loading an XML file to the browser's memory, the data read in is organized in an object, the DOMDocument object. You can load data into this object, navigate it, and query its nodes. The DOMDocument object is an extension of the DHTML DOM. In this column, we'll focus on the graph representation of DOMDocument, and on how to populate it from an XML file. We'll show you how to load an XML file, and how to monitor the XML parsing and object building. We'll show you how to detect if an error occurred during parsing and building, and what information is available for accurate and effective error reporting.

In this column you will learn:

• How to draw the DOMDocument graph
• How to read an XML file
• How to monitor XML parsing and building
• How to report errors during parsing and building