W3C home > Mailing lists > Public > public-rdf-in-xhtml-tf@w3.org > October 2008

Re: RDFa review ... too late, but maybe still helpful for the group

From: Shane McCarron <shane@aptest.com>
Date: Tue, 07 Oct 2008 21:51:37 -0500
Message-ID: <48EC2039.30804@aptest.com>
To: Ben Adida <ben@adida.net>
CC: Axel Polleres <axel.polleres@deri.org>, public-rdf-in-xhtml-tf@w3.org, alxandre.passant@deri.org, Benjamin Heitmann <benjamin.heitmann@deri.org>

My comments are in line.  Mark, there is an item in here that we really 
need your input to react to.  I know you are buried, but 5 minutes would 
be really helpful.

Ben Adida wrote:
> Hey folks,
> Thanks for your review!
> A few comments below in response to your questions. Mark, Shane, and
> Steven might chime in to enhance the response :)
> We'll do our best to incorporate as much as we can here, though we are
> on a tight deadline to publish. Comments below.
>> The inconsistent specification of the CURIE syntax is the main critical
>> question we have, which occurs in more than one section.  The main
>> question is whether a CURIE must contain a colon, or need not.  The
>> formal syntax definition in section 7 says
>>> curie       :=   [ [ prefix ] ':' ] reference
>> but the definition of the XML Schema datatype in appendix B.1 does not
>> reflect the fact that the colon can be missing:
>>> <xs:simpleType name="CURIE">
>>>     <xs:restriction base="xs:string">
>>>       <xs:pattern value="[\i-[:]][\c-[:]]*:.+" />
>>>     </xs:restriction>
>>> </xs:simpleType>
> Good point about the inconsistency, we'll be clearer about that. A valid
> CURIE need not have a colon, but CURIEs in @rel/@rev *do* need a colon,
> and that is indeed an intended design tidbit: we don't want rel="foobar"
> to mean something by default, but we *do* want rel="next" to mean what
> it has always meant.
This was actually already corrected.  The XSD now matches the BNF.  And 
yes, this means that rel="foobar" is syntactically valid were the 
definition of @rel to use that datatype.  It will not when we have an 
XML Schema implementation of RDFa+XHTML - @rel and @rev will have a 
custom datatype that contains the reserved values.
>>> @rel and @rev support both XHTML link types and CURIEs
>> If XHTML link types like "next" turn out to be CURIEs, this will have to be
>> rephrased.
> We could say "prefixed CURIEs," but I'll let Mark and Shane explain further.
"next" is syntactically legal as a CURIE.  However, section 7 says "the 
*mapping to use when there is no prefix* is not defined, which 
effectively prohibits the use of CURIEs that do not contain a colon;"  
This means that within the context of RDFa+XHTML "next" is NOT permitted.
>>  So if redefining the default namespace does not have any impact on the URI prefix
>> mapping that is relevant for CURIEs, this should be explained by a
>> dedicated example.
> We might make it a dedicated test case, although I could have sworn we
> had one (but I can't find it yet). I don't think we'll change language
> at this point, as this has not been an issue so far. Mark, Shane, feel
> free to correct me.
Every test case defines a default namespace that never has an effect on 
the generated triples.
>> == 5.5 Sequence ==
>>> 9. . the actual literal value is obtained as follows:
>>> * as a [typed literal] if:
>>>   * @datatype is present, and does not have an empty value
>> Note that this condition covers the case @datatype=rdf:XMLLiteral, so it
>> should be changed to: "does not have an empty value, nor the value
>> XMLLiteral"
> I think technically that's covered by the other condition matching, but
> you're right that this would help clarify things and be more precise.
This is probably correct, but I am reluctant to make this change without 
Mark's agreement and explicit wording.
>> ==== Using @src ====
>>> The complete mark-up yields three triples:
>>> ...
>>> <photo1.jpg> xh:license <http://...> .
>> xhv is the correct prefix.
> Good catch!

Fixed.  Thanks!

Shane P. McCarron                          Phone: +1 763 786-8160 x120
Managing Director                            Fax: +1 763 786-8180
ApTest Minnesota                            Inet: shane@aptest.com
Received on Wednesday, 8 October 2008 02:52:39 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:50:29 UTC