XOM API for Processing XML with Java

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

At 13:13 06/02/2006, Elliotte Harold wrote:
> peter murray-rust wrote:

Many thanks for all the useful feedback.

> > Personally as a user of XOM I would find it much easier if all 
> > namespaces were easily available in all their descendant elements.
>
> You can get a list of the namespaces in scope on an element using an 
> XPath query such as
>
> Nodes namespaces = element.query("namespace::node()");

I think this will do what I want.

At the risk of appearing foolish, I'll outline my reason for using 
this construct. When I saw "xsd:double" etc. in XSD I assumed this 
was a useful extension of XML. Also, because QName was a defined 
dataType in XSD I assumed this was a Good Thing To Do.

I have a need to access (remote) objects by their ids, and as I 
cannot guarantee that they are unique across the planet (our 
community is too anarchic) I assume they are locally unique within a 
file (document) identified by a namespace. Thus:
<scalar xmlns:foo="http://foo"; dictRef="foo:abc">1.23</scalar>
points to the object with id="abc" within a namespace of http://foo. 
This allows any document creator to identify a document with a 
namespace (unrelated to the namespace on the elements). So there are 
times when I need to compare a namespace with the namespaces in scope 
in the document.

Recent discussion suggests that namespaced attribute and content 
values are considered harmful. It is possible to construct a system 
which does the same independently of XML machinery but it is more 
work and I thought I was gaining something from XML that helped.

P.


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