XOM API for Processing XML with Java

[peter murray-rust <pm286 AT cam.ac.uk>]

At 13:09 19/12/2005, Elliotte Harold wrote:
> peter murray-rust wrote:
>
> > [Note - I do not like the idea of adding schema 
> > references within the XML instance but it seems 
> > to be one of the current ways of using XSD. I 
> > do not actually like XSD at all, but feel that 
> > I am constrained to use it - it solves ca 10% 
> > of validation problems in chemistry. Schematron 
> > adds somewhat more but ultimately we need much more expressive semantics.]
>
> I suspect you need a custom type library and 
> RELAX NG to really handle this use case. See 
> http://www-128.ibm.com/developerworks/java/library/x-custyp/

Many thanks - I think this is very close to my 
current approach which is to subclass every 
element at add the constraints in Java. You are 
starting to convince me that I should refactor to 
RELAX-NG - (how) does XOM support this - is it 
likely to be less problematic than  Xerces? My 
schema is extensive but simple and modular - all 
elements, attributes and types are in separate 
xsd:* elements so I hope it should be easy to 
transform it to RELAX-NG in an automatic manner.

I hope this isn't off-topic (if so please mail 
separately), but my design includes the use of 
extensive dictionaries (perhaps with 1000 or more 
terms) all of which can be turned into 
schema-elements. There is a core of objects (ca 
100) that serve the most straightforward cases 
and the others (for example a 4th rank tensor) 
are assembled on demand from (currently) XSD-like 
code in the dictionaries. It might make sense for 
this to use RELAX-NG instead.

...
<erh>
This error message comes from Xerces. See 
http://issues.apache.org/jira/browse/XERCESJ-1124 
which I just filed. However your specific problem 
(50% certainty) is using a FileReader. Don't do 
that. FileReaders don't know where they came from 
and thus cannot resolve relative URLs. Plus 
they're more likely to get the encoding wrong than right. Instead try this:
</erh>

Thanks for this - it sounds a promising diagnosis.

P.



> --
> Elliotte Rusty Harold  elharo AT metalab.unc.edu
> XML in a Nutshell 3rd Edition Just Published!
> http://www.cafeconleche.org/books/xian3/
> http://www.amazon.com/exec/obidos/ISBN=0596007647/cafeaulaitA/ref=nosim

Peter Murray-Rust
Unilever Centre for Molecular Sciences Informatics
University of Cambridge,
Lensfield Road,  Cambridge CB2 1EW, UK
+44-1223-763069