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

From: Ivan Herman <ivan@w3.org>
Date: Mon, 15 Dec 2008 10:40:48 +0100
Message-ID: <49462620.3070504@w3.org>
To: Florian Schmedding <schmeddi@informatik.uni-freiburg.de>
CC: 'Richard Cyganiak' <richard@cyganiak.de>, 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>
Hi Florian,

I can very well see your point and your example is indeed a good one.
However, at this time of the game, we should have a clear statement from
the Working Group based on the discussion records and add a clear test
case... I can adapt my distiller to whatever is decided!

Thanks

Ivan

Florian Schmedding wrote:
> [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
> 

-- 

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 Monday, 15 December 2008 09:41:29 GMT

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