W3C home > Mailing lists > Public > www-tag@w3.org > November 2002

My action item on RDDL/RDF

From: Tim Bray <tbray@textuality.com>
Date: Sun, 10 Nov 2002 12:18:43 -0800
Message-ID: <3DCEBF23.6040105@textuality.com>
To: WWW-Tag <www-tag@w3.org>

In connection with my action item, I've posted a revised RDDL draft at 
http://www.textuality.com/xml/rddl2.html.  It's kind of rough and 
hand-authored.  For those who don't want to plow through the whole 
thing, section 1 should do it, in particular the example in section 1.2.

I should note that this doesn't represent 100% consensus between 
Jonathan and myself, he has some outstanding concerns that I more or 
less wore him down on.  I'll run through them and I've cc'ed Jonathan so 
he can correct me if I'm off the rails.  I'm going to use English rather 
than any of the RDF syntaxes.

Suppose I have namespaces L1 and L2 and there's a DTD L.dtd that you can 
use with either.  So in the RDDL for L1 I say:

- the nature of L.dtd is that it's a DTD
- the purpose of L.dtd is strict-validation

and in the RDDL for L2 I say

- the nature of L.dtd is that it's a DTD
- the purpose of L.dtd is forgiving-validation

Now the 2nd RDF assertions in the two RDDLs are in conflict.  The reason 
is that they involve 2 different namespaces, but the namespace doesn't 
get into the RDDL.  But it could, be cause we know the URI of the 
namespace ("" - this is the namespace doc remember) so we can make 
assertions about it.  Jonathan was proposing something like

- "" has a property called strict-validation-schema whose value is L.dtd
- the nature of L.dtd is that it's a DTD

and you get no contradictions.  BUT, you get way more tangled-looking 
syntax and it gets way harder to predefine a bunch of precooked purpose 
vocabularies AND it gets harder to automatically detect the "purpose" 
property.  So this would be an example of the "RDF tax" that has for 
example doomed the RDF version of RSS.

I personally think the RDF version is easier to read and understand than 
the XLink version, but I can see the other side of this too.  -Tim
Received on Sunday, 10 November 2002 15:18:45 UTC

This archive was generated by hypermail 2.3.1 : Wednesday, 7 January 2015 15:32:35 UTC