- From: Ivan Herman <ivan@w3.org>
- Date: Wed, 09 Jan 2008 11:53:33 +0100
- To: Mark Birbeck <mark.birbeck@formsPlayer.com>
- Cc: Manu Sporny <msporny@digitalbazaar.com>, RDFa <public-rdf-in-xhtml-tf@w3.org>
- Message-ID: <4784A7AD.5040008@w3.org>
Mark Birbeck wrote: >> In all models >> >> <> foaf:knows <#me> . >> >> is generated if there is an implicit @about="" on the <body> element. >> But I am not sure that is the case, in which case that triple is not >> generated either (sorry Ben, we seem to disagree on that). > > Ok...we need to check this. I think we say that the document URI > itself is the default for @about (which may be set by <base>), but > we'll need to double-check. But since we have agreed that this is what > we _want_, let's just assume for now that this _is_ the triple > generated. > I agree. And I think we did have a discussion in the path about this, when you proposed to have an implicit @about="" on the <head> element that I misunderstood and I thought you meant to have this implicitly on the <html> element. I am not sure where we are with that. I still believe that having an implicit @about="" on <html> would make the trick. (Well... Shane was not sure whether we should allow any RDFa attributes on <html>; the current DTD does not. I asked Steven last Monday about that, he said that some old IE version's DOM implementation made it difficult if not impossible to access attributes on the <html> element, hence the restriction. We may have to test this separately.) > >> I first believed that in the model of Mark the >> >> <#me> foaf:knows <#ben> . >> >> is also generated regardless of whether the previous triple is >> generated. I then had to re-read the syntax document to find out, via >> the processing steps, that this is not so. (@rel has a higher priority >> in setting [new subject], ie, it will be set to null, and that is not >> send down to <span>) >> >> Which by itself is also significant (thanks, Manu!): if there is an >> uncertainty on this for us, too, this shows the extra complexity induced >> by the usage of @resource (sorry Mark:-)... > > I'm not sure if it's completely logical to say that a proof of some > kind of extra complexity in the rules is that you had to read them! > But then I'm no mathematician. ;) > :-) None of the end users will read that part of the document, and to answer this (edge) case one has to. And that is what bothers me. Anyway... > >>> ----------------------------------------------------------------- >>> <div href="#me"> >>> <span rel="foaf:knows" href="#ben"> >>> </div> >>> ----------------------------------------------------------------- >>> >> In the model of Mark @href sets the [new subject] in <div>, which is >> then turned into [current subject] that is sent down to <span>. Ie, the >> >> <#me> foaf:knows <#ben> . >> >> will be generated. > > Yes. Ben seems ok with this. Are you, Ivan? > Well... I am not sure, and I am not convinced. I am absolutely content to use @about in such a case and not @href; I am concerned by the appearance of unexpected triples again. (Note that this may be considered as a mild edge case, too: after all, @href can appear on <a> only in XHTML1) > >>> ----------------------------------------------------------------- >>> <div resource="#me" rel="foaf:knows"> >>> <div resource="#ben"> >>> <a rel="foaf:knows" href="#mark">Mark</a> >>> </div> >>> </div> >>> ----------------------------------------------------------------- >>> >>> -- manu >>> >> <#me> foaf:knows <#ben> . >> >> will be generated for the same reason. > > Not in my model...no. There is actually no connection between the > outer statement and the inner one. It could just as easily be written: > Oops, I am sorry, I was wrong. In my analysis of your model, one would get <> foaf:knows <#me> . <#ben> foaf:knows <#mark> . which is what you say below. Sorry about that. > <div resource="#me" rel="foaf:knows"> > </div> > > <div resource="#ben"> > <a rel="foaf:knows" href="#mark">Mark</a> > </div> > > The first statement gives: > > <> foaf:knows <#me> . > > as usual, and the second gives: > > <#ben> foaf:knows <#mark> . > > Ben indicated that he is happy with the second statements generating > said triples; are you? > Well, this is exactly the same question as the one above because we aim at a symmetry of @href and @resource. Mark, in one of your previous mail you try to separate this case from the behaviour of @href/@resource with hanging rels and which was the core of our discussions the past few days. I am not sure that is a good idea; if we do _not_ agree on your model with hanging rels, but we would agree on this usage of @href/@resource, we may then end up with some sort of a spagetti specification which introduces all kinds of extra cases when @resource is around but without @rels, etc. I am not sure that is wise... That also adds to me discomfort to the previous question you raised. Ivan > Regards, > > Mark > -- 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 Wednesday, 9 January 2008 10:53:27 UTC