xml-dev - XML and Healthcare, RDF spec bug was: Re: Default Namespaces - whydon't

[Jonathan Borden <jborden@mediaone.net>]

Stefan Haustein wrote:

> Jonathan Borden wrote:
> >
> >  Clarify RDF? :-))) I've been getting into this recently because I
decided
> > to design our next version healthcare repository around RDF, which I am
> > using to represent HL7 models.
>
> Did you compare RDF to the serialization format included in SOAP?
> I am still in doubt which to choose for my application.

1) RDF was designed for modelling the rich types of semantic relationships
as found in healthcare and modelled in HL7 (e.g. a person has a doctor, a
person has an insuror, a doctor both a person and a healthcare provider, a
patient is a person, a patient had an encounter with a provider etc. etc.).
If healthcare records are important to preserve on a long term basis, they
need to be stored in a specified format that will allow this, hence XML. RDF
provides the necessary semantic structure on top of the XML data.

2) SOAP is not a w3c, disa, ietf, iso or other accepted standard. HL7 is,
XML is, RDF is.
Though I'm sure there are some who might use SOAP serialization formats for
defining application level formats, I view SOAP as a messaging format. HL7V3
(will) also define a messaging format that is more appropriate for the
specific needs of healthcare, though arguably one could use something like
SOAP or ebXML for particular application level communications.

>
> >     In fact, the RDF syntax spec makes (IHMO)  the erroneous assumption
that
> > attributes inherit the namespace of the enclosing element (witness the
use
> > of <rdf:y about="..."> rather than <rdf:y rdf:about="...">
>
> In my opinion, there is nothing in the XML spec that forbids
> RDF to make such an assumption at application level if the
> attribute has no explicit namespace.
>

    Namespace issues are defined in the XML Namespace rec. In particular:
http://www.w3.org/TR/1999/REC-xml-names-19990114/#defaulting states
unequivocally:

"
A default namespace is considered to apply to the element where it is
declared (if that element has no namespace prefix), and to all elements with
no prefix within the content of that element. If the URI reference in a
default namespace declaration is empty, then unprefixed elements in the
scope of the declaration are not considered to be in any namespace. Note
that default namespaces do not apply directly to attributes. "

and further in http://www.w3.org/TR/1999/REC-xml-names-19990114/#uniqAttrs:

"
However, each of the following is legal, the second because the default
namespace does not apply to attribute names:

<!-- http://www.w3.org is bound to n1 and is the default -->
<x xmlns:n1="http://www.w3.org"
   xmlns="http://www.w3.org" >
  <good a="1"     b="2" />
  <good a="1"     n1:a="2" />
</x>
"

So it appears at least to me that there ought be no ambiguity about placing
attributes in the enclosing namespace of the enclosing element. I consider
this a "bug" in the RDF spec which needs to be layered on top of XML names.

Jonathan Borden
http://www.openhealth.org