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Re: Markup questions: html/body, datatype="", double predicates

From: Florian Schmedding <schmeddi@informatik.uni-freiburg.de>
Date: Sun, 14 Dec 2008 12:27:44 +0100
To: "'Ivan Herman'" <ivan@w3.org>, "'Richard Cyganiak'" <richard@cyganiak.de>
Cc: <public-rdfa@w3.org>, "'W3C RDFa task force'" <public-rdf-in-xhtml-tf@w3.org>, "'Mark Birbeck'" <mark.birbeck@webBackplane.com>, "'Ben Adida'" <ben@adida.net>, "'Hausenblas, Michael'" <michael.hausenblas@deri.org>
Message-ID: <01b601c95dde$fcfef520$f6fcdf60$@uni-freiburg.de>

[snip]
> >>
> >> Again, this behaviour is actually the right one. Labelling a subtree
> >> as a @property means that this subtree is, sort of, removed from the
> >> RDFa processing.
> >
> > Are you sure?
> >
> > Quoting the spec: “Processing generally continues recursively through
> > the entire tree of elements available. However, if an author
> indicates
> > that some branch of the tree should be treated as an XML literal, no
> > further processing should take place on that branch, and setting this
> > flag tofalse would have that effect.”
> >
> > It doesn't say anything about stopping when the author indicates that
> > some branch should be treated as a plain literal.
> >
> > Also relevant: “Once the triple has been created, if the [datatype]
> of
> > the [current object literal] is rdf:XMLLiteral, then the [recurse]
> > flag is set to false.”
> >
> > Reading this makes me just more confused. I'm not sure how to
> > interpret this. Obviously, if I set @datatype to rdf:XMLLiteral, then
> > it should not recurse, that's clear.
> >
> > But what if I don't specify @datatype at all? This will generate an
> > XML literal if there's markup in the child nodes. But does it trigger
> > the condition in this sentence? Is the [datatype] rdf:XMLLiteral in
> > that case, or is the [datatype] unspecified? The question is if
> > [datatype] refers to the @datatype attribute here, or to the RDF
> > datatype of the resulting RDF node, in the RDF abstract syntax sense.
> >
> 
> Hm. Richard, you should have joined us earlier:-)
> 
> - I do not think there is a problem with XMLLiteral case you describe
> in your last remark. The text you quote in step 9 of the processing
> model, ie,
> 
> [[[
> Once the triple has been created, if the [datatype] of the [current
> object literal] is rdf:XMLLiteral, then the [recurse] flag is set to
> false.
> ]]] (Section 5.5, step 9)
> 
> does not refer, in my view, to the @property value but the datatype of
> the generated of [current object literal] which, according to item
> three in step nine will be XMLLiteral.
> 
> - But, indeed... what happens if @datatype="" is used? Then item two of
> the said step 9 enters into effect, which means to generate a plain
> literal of the text nodes but, you are absolutely right, the remark
> given at the end of step 9 does not give any more information on
> recursion! More exactly, the text could be read as saying: one has to
> move on with the recursion.

Ivan, I agree that one has on move on with recursion here. I think that
it is also useful, consider if you change your example to s.t. like:

<span about="#me" property="ex:name" datatype="">Florian
  <span property="ex:lastname">Schmedding</span>
</span>

So if there's no contradictory example, I'd prefer the current behavior
because in contrast to XML literals, the value of ex:name does not
cover the inner markup (<span> here). Thus it can be evaluated.

Florian

> 
> My recollection of the discussion in the group was that recursion is
> not required in that case either. But yes, this is not in line with the
> spec as it stands now.
> 
> To add insult to indjury:-) I do _not_ think there is a test for this!
> I looked through:
> 
> http://www.w3.org/2006/07/SWD/RDFa/testsuite/xhtml1-testcases/rdfa-
> xhtml1-test-manifest.rdf
> 
> and I have not found anything:-( Ie, unless I missed a test, we have a
> problem!
> 
> I attach the test case (0XXX.html) and two possible outputs, namely
> 0XXX.sparql and 0XXX-a.sparql. 0XXX.sparql works according to my
> understanding/recollection of the discussions, ie, @property="" cuts
> the recursion altogether, 0XXX-a.sparql may be the correct reading of
> the spec. If the latter, than there is a bug in the distiller:-(. In
> both cases I think the test case should be expanded...
> 
> (actually, my collection says that _any_ @property value cuts
> recursion, not only @property="" or XMLLiteral...)
> 
> Thanks Richard!
> 
> Ben, Mark, Michael, others: what do you think?
> 
> 
> Ivan
> 
> 
> > Hope there's a test case in the suite that answers this question ;-)
> >
> > Richard
> >
> >
> >
> >>
> >>
> >>
> >>>
> >>> 3. Double predicates. Just to confirm, is it always allowed to have
> >>> multiple CURIEs in the CURIE-accepting properties?
> >>>
> >>> rel="foo:prop1 bar:prop2"
> >>> rev="foo:prop1 bar:prop2"
> >>> property="foo:prop1 bar:prop2"
> >>> typeof="foo:prop1 bar:prop2"
> >>>
> >>> I assume that all of these are legal and will result in two triples
> >>> instead of one?
> >>>
> >>
> >> Yes.
> >>
> >>>
> >>> That's all for now. Finally, in case that some of the folks who
> >>> influenced the design of RDFa on this list: Let me say that I'm
> >>> impressed with the result.
> >>
> >> Thank you!
> >>
> >> Ivan
> >>
> >>
> >>>                            Obviously a lot of thought went into
> >>> every detail of the language and the result is pleasing and
> elegant.
> >>> Finally, here's an RDF syntax that does not suck and makes RDF
> publishing fun!
> >>>
> >>> Cheers,
> >>> Richard
> >>>
> >>
> >> --
> >>
> >> Ivan Herman, W3C Semantic Web Activity Lead
> >> Home: http://www.w3.org/People/Ivan/
> >> PGP Key: http://www.ivan-herman.net/pgpkey.html
> >> FOAF: http://www.ivan-herman.net/foaf.rdf
> >
> 
> --
> 
> Ivan Herman, W3C Semantic Web Activity Lead
> Home: http://www.w3.org/People/Ivan/
> PGP Key: http://www.ivan-herman.net/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Sunday, 14 December 2008 11:28:24 GMT

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