XML in a Nutshell, 3rd Edition

Alternative Approaches

Authoring your web pages in XML does not necessarily require serving them in XML. Fourth-generation and earlier browsers that don’t support XML in any significant way will be with us for some time to come. Servicing users with these browsers requires standard, ordinary HTML that works in any browser back to Mosaic 1.0.

One popular option is to write the pages in XML but serve them in HTML. When the server receives a request for an XML document, it automatically converts the document to HTML and sends the converted document instead. More sophisticated servers can cache the converted documents. They can also recognize browsers that support XML and send them the raw XML instead.

The preferred way to perform the conversion is with an XSLT stylesheet and a Java servlet. Indeed, most XSLT engines, such as Xalan-J and SAXON, include servlets that do exactly this. However, other schemes are possible, for instance, using PHP or CGI instead of a servlet. The key is to make sure that browsers only receive what they know how to read and display. We’ll talk more about XSLT in the next chapter.