RDF in XHTML Task Force

Action Items

ACTION: Ben to put up information on "how to write RDFa" with screencast possibly and instructions on bookmarklet. [recorded in http://www.w3.org/2008/11/06-rdfa-minutes.html#action12] [CONTINUES]

ACTION: Manu to write summary for Semantic Web Use Cases for Ivan. [recorded in http://www.w3.org/2008/09/11-rdfa-minutes.html#action09] [CONTINUES]

ACTION: Manu to update wiki page on current consensus for @prefix [recorded in http://www.w3.org/2009/04/16-rdfa-minutes.html#action15] [DONE]

<msporny> http://rdfa.info/wiki/Alternate-prefix-declaration-mechanism

ACTION: Mark create base wizard suitable for cloning [recorded in http://www.w3.org/2008/09/11-rdfa-minutes.html#action12] [CONTINUES]

ACTION: Mark to send Ben ubiquity related wizard stuff [recorded in http://www.w3.org/2008/11/20-rdfa-minutes.html#action11] [CONTINUES]

ACTION: Mark write foaf examples for wiki [recorded in http://www.w3.org/2008/09/11-rdfa-minutes.html#action13] [CONTINUES]

ACTION: Michael to create 'RDFa for uF users' on RDFa Wiki [recorded in http://www.w3.org/2008/09/11-rdfa-minutes.html#action14] [CONTINUES]

ACTION: Ralph or Steven fix the .htaccess for the XHTML namespace [recorded in http://www.w3.org/2009/01/08-rdfa-minutes.html#action01] [CONTINUES]

ACTION: Ralph think about RSS+RDFa [recorded in http://www.w3.org/2008/09/11-rdfa-minutes.html#action15] [CONTINUES]

RDFa Updates (RDFa use cases, HTML5 micro-data thread on WHATWG)

Michael: Re RDFa validator

http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Apr/0089.html

looking http://www.w3.org/TR/2008/REC-rdfa-syntax-20081014/#rdfa-attributes

someone did href=[foaf:Person]

Michael: I wondered if we can write a validator that checks that each of the attribute values is of a correct type; CURIE, URI, etc.

Mark: no, I don't think this is easy
... property="http:..." would be flagged as a CURIE but then later you'd notice that there was no 'http' prefix defined

<mhausenblas> @datatype="http://www.....org/xml/schema/string"

<mhausenblas> http: is the token

<inserted> scribenick: ralph

Mark: it's almost impossible to distinguish

Michael: but the URL schemes are registered

<mhausenblas> coming from http://www.iana.org/assignments/uri-schemes.html

Michael: so perhaps one could note when registered schemes are mis-used as prefixes

Mark: sure, a validator could be as strict as it wants
... but there CURIE spec does not disallow using 'http' as a prefix, nor any other scheme type
... and I'd oppose such a restriction

Shane: I've seen people choose to define 'http' as a prefix; it's a useful workaround
... I consider the ability to define http as a prefix is a feature

Manu: it's a nice trick but I don't think we should be recommending it
... Michael's question is 'what advice should a validator give?'
... the validator could just note when a registered scheme is used as a prefix, not disallow it

Shane: it's more important to flag cases where a CURIE prefix is used but never defined

Michael: I could validate strings starting with http: against the HTTP URI syntax spec
... a warning or hint -- not error -- might help for other registered schemes, even though there may not be many that would accidentally be used by a document author

Mark: if the validator wants to complain about registered schemes as prefixes, then it should complain as soon as it sees xmlns:http=

Shane: it would be fine to say "This prefix has not been defined; it looks like you're trying to use a URI. Here's what to do instead ..."

<msporny> http://rdfa.info/wiki/Rdfa-use-cases

msporny: we have some 25 UC now

<msporny> http://lists.whatwg.org/pipermail/whatwg-whatwg.org/2009-April/019374.html

msporny: people are discussing UC

markbirbeck: RDFa works already fine in HTML5
... we continue to support people that want to use it
... and as a matter of fact people are using it

msporny: there seems to be a shift from non-data mechanism awareness to data awareness in HTML5

markbirbeck: it is clear that the authority is here, in the end
... and we're happy to give them advise *how* to implement it in HTML5
... RDFa has solved the decentralised voc management issue
... and one should encourage HTML5 not to become incompatible

ShaneM: RDFa helps HTML5 to support the Semantic Web

<ShaneM> RDFa helps EVERYTHING support the semantic web

Michael: there are other routes as well, just to note, for example http://ld2sd.deri.org/lod-ng-tutorial/

ShaneM: next time when Ben and Steven are around we might continue this

ACTION: Manu to talk with Ben about recent WHATWG use case activity. [recorded in http://www.w3.org/2009/04/30-rdfa-minutes.html#action10]

see also http://bitbucket.org/mhausenblas/lod-ng-tutorial/

OWL2 Manchester Syntax eschewing CURIEs - need to comment (Shane)

ShaneM: OWL WG decided not to use CURIEs
... rational was not clear, sad, though

<markbirbeck> One more 'rdfa update': http://webbackplane.com/mark-birbeck/blog/2009/04/23/more-rdfa-goodness-from-uk-government-web-sites

ShaneM: seems there was a misunderstanding with CURIEs (re XMLNS)
... but that will change
... they invented an abbreviated URI mechanism

<msporny> OWL2 Manchester Syntax document: http://www.w3.org/TR/2009/WD-owl2-manchester-syntax-20090421/

ShaneM: but not a CURIE, funny enough
... XHTML2 WG will send in a LC comment to object re this

<msporny> +1 for commenting on CURIEs

<mhausenblas>+1

ShaneM: will prepare a comment for XHTML2 WG, RDFa TF may join
... due on 12 May

<Ralph> OWL-WG comment on CURIE [Sandro Hawke 2009-04-09]

<Ralph> Various issues with using CURIEs in OWL [Bijan Parsia 2009-04-09]

markbirbeck: RIF also refers to CURIEs

<Ralph> (the SPARQL REC is dated January 2008)

Michael: the new SPARQL Update might change this ;)

Framing the @profile discussion

<msporny> http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Apr/0082.html

-> http://rdfa.info/wiki/RDFa_Profiles

ShaneM: I think we need to define the requirements as well.
... we're trying to figure out a way to define CURIE rules external to the document.

markbirbeck: I agree.

<ShaneM> where part of those rules include prefix mappings, and part include defining additional reserved words

markbirbeck: Essentially, we want to get the same simplicity that Microformats has.
... We might have a second use case - importing a collection of new tokens.

ShaneM: but you could do it with another mechanism.
... That is a different problem than what we're currently discussing.

markbirbeck: that is true, but where this is heading - how do we set ourselves up for a future that we know is coming?
... we need to make sure the rules get placed into a separate graph.

ShaneM: As long as we're generating triples, we should be good.

markbirbeck: Are you saying that the external import mechanism is more important?

ShaneM: I think they're different, not tied to one another.

ACTION: Manu to define a set of requirements and questions for extending CURIEs in an external document on the RDFa wiki. [recorded in http://www.w3.org/2009/04/30-rdfa-minutes.html#action11]

<Ralph> SPARQL PN_LOCAL BNF (allowed chars in prefixed names)