DOM Support

Microsoft has included XML support to its Document Object Model (DOM).  Since IE5 runs on a Windows platform, Microsoft implemented the DOM as a Component Object Model (COM) library called MSXML.  This will eventually allow the Microsoft XML processor to be accessible to any number of other languages and tools such as Visual Basic, Visual C++, and Microsoft Office.  

The DOM is accessible either directly within the scripting context or as a separate library of objects, depending on how you are using XML.  The first method of using scripting XML within HTML will be as Data Islands.  Data Islands are blocks of XML that are embedded within an HTML document.  Client-side script can be embedded within the HTML to manipulate the data within the XML Data Island. When using Data Islands, we can utilize the XML just like any other named HTML element, so it is not necessary to directly reference the MSXML library.  We will get to that in the next lesson.

The real advantage of using XML Data Islands is that the XML is embedded within the HTML, and the whole thing is delivered to the client in one pass.  In this way, there does not need to be repeated communication with the client.  In our lesson examples, we are going to embed XML data islands within our HTML documents, and dynamically generate the content of the document on the client, instead of on the server.