XSLT, which stands for Extensible Stylesheet Language Transformations, is a declarative, XML-based language used for the transformation
of XML documents into other XML documents. The input document is used to create a new output document using the data in the
input document along with the rules described in the XSLT document. The style of programming is that of a functional language
with string matching, rather than a procedural language. Learning to create XSLT 'programs' is not difficult, but changing
to the functional programming paradigm for those accustomed to procedural languages does require a different approach to problem
solving.
Note: The term XSL is often used to mean XSLT. XSL is actually a family of standards that includes XSLT. For most practical purposes,
this subtle distinction can be ignored.
XML Extensions creates (exports) or consumes (imports) only documents which 'match' the hierarchical structure of a COBOL
record area. When the external requirements for an XML document do not achieve this match, XSLT is used. For example, SOAP
web services require the creation of a very complicated XML document, the WSDL, to describe the web service. Xcentrisity BIS
uses XSLT to create the WSDL from a COBOL data description - matching the relatively simple data layout to the complex WSDL
XML document.
Note: The following discussion uses terminology that presumes an understanding of XSLT. A thorough explanation of XSLT is beyond
the scope of this tutorial. Several excellent books and online tutorials are available that teach XSLT.