↑
Main Page

XML in JavaScript

With the rising popularity of XML, JavaScript developers were clamoring for a way to make use

of it in client-side Web development. When the fourth-generation browsers were released, many

developers began writing their own objects for the manipulation of XML using JavaScript. Hearing

the call, some browser developers boldly pushed toward adding support for XML and XML-

related language on the client side.

XML DOM Support in Browsers

Even though XML and the DOM have become an important part of Web development, there are

still only two browsers that support client-side XML manipulation. Not surprisingly, they are the

two most popular browsers in the world: Internet Explorer and Mozilla.

XML DOM support in IE

When looking to add XML support to Internet Explorer, Microsoft looked outside of JavaScript to

their ActiveX-based library called MSXML. MSXML was developed to provide developers with

the first DOM implementation for Windows. As an ActiveX control, MSXML could be used in con-

junction with Visual Basic, C++, and other Windows-based development environments. It made

sense to use what the company was already offering as the basis for client-side XML support.

To create an ActiveX object using JavaScript, Microsoft introduced a class called

ActiveXObject

The constructor for

ActiveXObject

takes one argument, which is the string identifying the

ActiveX object to instantiate. For example, the first version of the XML DOM object was called

Microsoft.XmlDom

. To create a new instance of this object, you would do this:

var oXmlDom = new ActiveXObject(“Microsoft.XmlDom”);

18_579088 ch15.qxd 3/28/05 11:42 AM Page 445