xml-dev - Re: XLink transformations

[Rick JELLIFFE <ricko@geotempo.com>]

Michael Kraus wrote:
> 
> Hello,
> 
> I'm currently working on an XML/XSL/XLink Browser
> (http://www.pms.informatik.uni-muenchen.de/lehre/projekt-diplom-arbeit/browser-toolkit.html)
> and have the following problem: The Browser takes as input an XML file,
> an XSLT stylesheet and an XLink linkbase. The links refer to elements in
> the XML file, of course. Now, if the XML file is translated into FO (or
> HTML), how can the browser know to which element(s) a certain XLink
> refers? 

I think we have to see XPointers and XPaths (in a document that is to be
transformed, and which are paths or pointers within that document) as
views rather than absolute data.  (Ulitmately, this may also apply to
ID/IDREFS and even keys.)

So when the document is transformed, the view is regenerated. In other
words,
the incoming XML document might have a path
  /x/y/z
and the document is transformed so the the top-level element is renamed
"a".
The path should be regenerated /a/y/z

The thing that should survive a transformation is not the text
specifying a XPointer or XPath but the pointer or path itself.   If
anyone cares to work out the details of what is needed for this, they
would be doing everyone a great service.

I think this is why is important that a schema language be able to
declare which value are XPaths or XPointers or whatever. (XML Schema
does not currently provide this directly, but I would imagine that the
neccessary types would be defined by other WG or body in short order.) 
Otherwise, how would a smart XSLT system know when to regenerate the
link. (And what happens if one end of the link disappears during the
transformation: what exception-handling should be in place for that.)  


Rick Jelliffe