XSLT, XPath, and XSL Formatting Objects
The main difficulty in working with a new and evolving technology such as XML is keeping up with the many changes being made to the specifications. For example, XSL is now being split into three different specifications: XSLT, XPath, and XSL Formatting Objects (XSL FO). XPath originated from XSL; therefore, as you saw earlier in this chapter, XSL uses essentially the same syntax as XPath. Because we've discussed XPath in detail in Chapter 6, we won't repeat the discussion here. The formatting object specification (the fo namespace) defines a set of formatting semantics developed as an XML vocabulary for working with documents such as PDFs.
- XSLT is a language for transforming an XML document to any other text-based document, such as an XHTML document. You can use XSLT to define templates for your output so that your XML data can be delivered to the templates. However, the existing Internet Explorer 5 XSL style sheets are not compliant with the final W3C XSLT recommendation. XSLT introduced many new features after Internet Explorer 5 was released. Therefore, we must update the style sheets to XSLT conformance to utilize these new features. Before we discuss how to update the XSL style sheets, let's take a look at the elements in XSLT.