Extract XML chunk as text from an XML document using XSLT

[th...@ascentialsoftware.com]

I am using Xalan C++ to process a style sheet that flattening an XML
document into a row column type of structure (another XML document, but very
flat, relational table like).

I define my own Formatter that I pass to the transform call as I want to
write the result of the transformation into a database row by row (so
catching the SAX even is a very good way for me to do that).

In some cases, I want the style sheet to select some nodes in the input XML
document and generate a row containing those nodes serialized as a string
(extract an XML chunk, as a string, from the original document and write it
as a column value).