Re: Extensibility in Syndication formats

[Dan Brickley <danbri@xxxxxx>]

* Sam Ruby <rubys@xxxxxxxxxxxxxxxx> [2004-08-18 07:52-0400]
> Dan Brickley wrote:
> >
> >Extensibility comes at a price, and designing something cleaner and
> >better than RDF will be an interesting endeavour. Finding a clean and 
> >syntactically graceful way of mapping _into_ RDF also comes at a price, 
> >as does (of course) simply using full RDF/XML syntax. The pre-IETF 
> >Atom community decided some time ago that they didn't find RDF/XML 
> >an attractive proposition, which I guess means we're going the route of 
> >defining an extensibility model that is somehow better than RSS 1.0's.
> 
> If you were to express that paragraph as a set of assertions, you would 
> find something missing.  I'm going to extract a few, please forgive my 
> inprecise way of expressing them:
> 
>   RSS 1.0 uses RDF.
>   RDF addresses some extensibility problems.
>   RDF/XML is a serialization syntax for RDF.
>   pre-IETF community didn't find the RDF/XML syntax attractive.
> 
> What can we conclude from this?

(That the baby is at risk because of the bathwater? ;)

> First, for purposes of this discussion, lets not debate the assertion 
> that RDF addresses extensibility issues, and simply treat it as a given. 
>  And let's assume, again for purposes of discussion, that the AtomPub 
> working group is interested in pursing a non-RDF/XML serialization syntax.
> 
> Even with all these assumptions, can we conclude that "we're going the 
> route of defining an extensibility model that is somehow better than RSS 
> 1.0's."?
> 
> I don't think so.
> 
> Hint: there are other serialization syntaxes than RDF/XML.
> 
> Further reading:
>   http://www.xml.com/pub/a/2003/08/20/dive.html
>   http://semtext.org/atom/utils.html
>   http://www.w3.org/2004/01/rdxh/spec

Yes. I skirted this a little, but that's an important message: 
it would be unfortunate to confuse RDF with it's current/primary
XML serialization (aka "RDF/XML").

BTW things are moving along with GRDDL, it is now published as a 
W3C Note, http://www.w3.org/TR/2004/NOTE-grddl-20040413/
(GRDDL, briefly, provides some conventions for pointing to an XSLT that 
turns some markup into RDF/XML).

The XHTML folk have also just shipped a Working Draft that shows a 
revision to the <link/> and <meta/> constructs in a way that allows 
it to be treated as an alternate XML notation for RDF graphs. See 
http://www.w3.org/TR/2004/WD-xhtml2-20040722/mod-metaAttributes.html#s_metaAttributesmodule
http://www.w3.org/TR/2004/WD-xhtml2-20040722/mod-meta.html#s_metamodule

Needless-ish to say, ongoing work on RDF querying
(http://www.w3.org/2001/sw/DataAccess/) is agnostic about RDF concrete
syntaxes, since it is couched in terms of the graph data model. The same
goes for all the vocabulary namespaces listed at
http://www.schemaweb.info/

cheers,

Dan