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Re: Empty @typeof...let's not lose this one again [was: two side issues on blank nodes...]

From: Ivan Herman <ivan@w3.org>
Date: Sat, 27 Mar 2010 19:14:56 +0100
Cc: W3C RDFa WG <public-rdfa-wg@w3.org>
Message-Id: <72CD7B22-E808-4E35-9FA6-064FFC59E15E@w3.org>
To: Mark Birbeck <mark.birbeck@webbackplane.com>

I guess the important is to remove those 5 words once and for all, and have it done:-)


On Mar 27, 2010, at 13:44 , Mark Birbeck wrote:

> Hi Ivan,
> It's amazing that we've discussed empty @typeof so often, yet it still
> doesn't seem to have become an erratum!
> I was so convinced that we'd resolved this, that I went back through
> the archives, and was surprised to discover that despite many
> discussions, we never actually came up with an erratum.
> (BTW, I'm not expecting anyone to read all of the following links, I'm
> merely trying to make the case as strongly as I can that we've
> discussed this many times, and so are fully aware of all the issues,
> and therefore we should try to get a vote on this as soon as we can,
> and hopefully be done with it once and for all.)
> On Fri, Mar 26, 2010 at 4:24 PM, Ivan Herman <ivan@w3.org> wrote:
>> While making an RDFa representation for the rdfa vocabulary the other
>> day, I ran into two small issues for which I did not find an unambiguous
>> answer or, if I believe it is unambiguous, I wonder whether we would not
>> want to make slight changes.
>> 1. Is the following 'legal'?
>> <div typeof=""><span property="a:b">bla</span></div>
>> Point 6 of the processing steps says: "If present, the attribute must
>> contain one or more URIs,", so it is not legal. Ie, to create a new
>> BNode one _has_ to use an explicit type to get something like
>> [ rdf:type SOMETYPE;
>>  a:b "bla" ]
> This was first raised by Toby and Micah back in 2008:
>  <http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2008Sep/0020.html>
> We seem to have discussed a related issue (raised by you and Ben), as
> mentioned here:
>  <http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2008Sep/0023.html>
> The related issue is that because parser writers are allowed to create
> triples in other graphs, we have to be conscious of bnode alignment,
> and the only way that we can ensure that alignment, is if the mere
> *presence* of certain attributes triggers bnodes, independent of the
> contents of the attribute. This applies to @rel, @rev and @typeof.
> That same issue popped up again -- prompted by Jeni, this time -- in
> the form of "what does it mean to 'ignore' an attribute":
>  <http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Sep/0085.html>
> Once again we reply along the lines that @typeof needs to generate a
> bnode, regardless of its content:
>  <http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Sep/0102.html>
> I even proposed some wording for section 5.5.4...but again it slips
> through the net.
> Then on my part things get worse, because I actually raise this issue
> with Manu as something we shouldn't forget:
>  <http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2009Oct/0045.html>
> but when I write up the proposal (URIs everywhere), I don't mention
> empty @typeof.
> Anyway, could we discuss this on the next call, and get it 'errated'?
> It involves the removal of about 5 words, so really ought not to have
> caused so much hassle.
> Regards,
> Mark
> --
> Mark Birbeck, webBackplane
> mark.birbeck@webBackplane.com
> http://webBackplane.com/mark-birbeck
> webBackplane is a trading name of Backplane Ltd. (company number
> 05972288, registered office: 2nd Floor, 69/85 Tabernacle Street,
> London, EC2A 4RR)

Ivan Herman, W3C Semantic Web Activity Lead
Home: http://www.w3.org/People/Ivan/
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Received on Saturday, 27 March 2010 18:13:41 UTC

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