- From: Dave Beckett <dave.beckett@bristol.ac.uk>
- Date: Thu, 24 May 2001 13:07:53 +0100
- To: w3c-rdfcore-wg <w3c-rdfcore-wg@w3.org>
- Cc: Jan.Grant@bristol.ac.uk
Another attempt after previous threads: http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001May/0088.html http://lists.w3.org/Archives/Public/w3c-rdfcore-wg/2001May/0050.html RDF M&S provides valid (if rather unclear) definitions of how to interpret an rdf:ID in a propertyElt in two cases, when the element is empty / non-empty. This answers the issue which asked why both ID and resource were not allowed on an empty element - there is a reason, and I point to it in the previous message. I feel that changing this definition to make it consistent with other parts of the syntax is not a good enough reason given that existing parsers may have implemented it. However, I have thought of another problem. XML parsers (I think) are not required to let applications distinguish between: <elm/> and <elm></elm> The only reference I can find to it is: Appendix D: What is not in the Information Set 7. The difference between the two forms of an empty element: <foo/> and <foo></foo>. -- XML InfoSet http://www.w3.org/TR/xml-infoset/#omitted In at least two common XML X parsers I have used (expat and libxml), these cannot be distinguished, they both return the same two events/callbacks: start element, end element. Since many systems use these as the standard XML parsers (this includes Perl, Apache, Python, GNOME) they thus may not be able to distinguish <prop:name rdf:ID="foo"/> and <prop:name rdf:ID="foo"/></prop:name> so RDF applications of these systems cannot make any decision based on this either. I feel that if this impacts any part of the RDF syntax that has a dependency on the distinction, it should be changed - and that includes this case. This is a much better reason to change - cannot be implemented in practice. For this reason I would propose that we make a change here that is implementable and consistent with the outcome of the Issue http://www.w3.org/2000/03/rdf-tracking/#rdfms-empty-property-elements owned by Jan Grant. and this issue should be on hold until that one is resolved. Over to you Jan... Dave
Received on Thursday, 24 May 2001 08:07:56 UTC