RE: [xml-dev] Serialization of XDM - Use cases / Proposal

 

Ouch.  If this cant be done in xquery syntax then my goal of de-serializing
an XML representation using a XQuery example implementation is out the door.

Here's my best shot ... 


attribute 
   { fn:QName( "U" , "P:N" ) } 
   { my:IdType( "S" ) }    (: wont work will it :( :)


Ok I admit I'm totally stumped.  *IS* there a way to re-animate this example
using XQuery (or XSLT?)  ?
I have a feeling that my goal of providing a reference implementation in
XQuery will be impossible.  Not even sure how to get element type
information re-animated.


 
I think that in XSLT, the following comes close:
 
<xsl:attribute name="P:N" namespace="U" type="my:IdType" select="'S'"/>
 
provided that the recipient has a schema (the correct schema) for the global
attribute declaration my:IdType. There are problems if the type is anonymous
(you might have to construct a variant of the original schema in which all
types have names). As for the isID property, it is ALMOST redundant in XDM:
it can in nearly all cases be inferred from the type annotation. The
exception is where IDness was established as a result of DTD validation
rather than schema validation. In that case, yes, I think you're going to
have difficulty reconstituting the original sequence using tools written in
XSLT or XQuery. (Actually, it hadn't occurred to me this was one of your
goals.)
 
XQuery 1.0 (unlike XSLT 2.0) doesn't allow validation against a type name,
and doesn't allow validation of individual attributes. 
 
Other limitations of using XSLT/XQuery
 
(a) neither language gives you any way of creating unparsed entities
 
(b) XQuery 1.0 gives you no way of creating arbitrary namespace nodes
 
Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay