- From: Niklas Lindström <lindstream@gmail.com>
- Date: Mon, 1 Oct 2007 14:18:33 +0200
- To: "Mark Birbeck" <mark.birbeck@formsplayer.com>
- Cc: "Ivan Herman" <ivan@w3.org>, "W3C RDFa task force" <public-rdf-in-xhtml-tf@w3.org>
Hi Mark, you beat me to it. :) I was just writing a response very close to your thinking. But I placed the stuff in the root element instead.. Would that not validate? (A note also: isn't @instanceof supposed to take only CURIE values? If so, you don't need/cannot use brackets in it, right?) I just paste my response here; I think it pretty much supports your reasoning: I think I'd like if this: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:foaf="http://xmlns.com/foaf/0.1/" instanceof="foaf:PersonalProfileDocument"> <head> <title>My profile</title> </head> ... would be enough. Though it seems (to the in the *trained* eye IMHO) that this generates a bnode for the entire content, I'd like to think that the root element provides ("captures") the current resource, meaning that its start tag has an implicit @about="" in it. Hence making the above mean exactly the same as: <html xmlns="http://www.w3.org/1999/xhtml" xmlns:foaf="http://xmlns.com/foaf/0.1/" about="" instanceof="foaf:PersonalProfileDocument"> <head> <title>My profile</title> </head> ... , which does achieve what we're after.. Or is this just a stretch, making @instanceof (seem to) behave differently on the root element? If so, is the latter so bad it really calls for something more? Best regards, Niklas On 10/1/07, Mark Birbeck <mark.birbeck@formsplayer.com> wrote: > > Hi Ivan, > > Thanks for forcing me to think it through more. :) I think that there > is probably a neat way to write this using current mark-up, although > working through it has highlighted something that I think we need to > clarify. > > Sticking purely with trying to make the rdf:type use-case easier > (i.e., rather than the general use of RDF/RDFS namespaces), there is > nothing to stop us doing this: > > <html > xmlns="http://www.w3.org/1999/xhtml" > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > <head> > <title>My profile</title> > <link about="" instanceof="[foaf:PersonalProfileDocument]" /> > </head> > . > . > . > </html> > > It looks odd, since there is no @rel or @rev, but it is allowed by the > syntax. But once you go down that route, you might as well use the > following, which is also allowed by the syntax, and is probably much > clearer in terms of intent: > > <html > xmlns="http://www.w3.org/1999/xhtml" > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > <head about="" instanceof="[foaf:PersonalProfileDocument]"> > <title>My profile</title> > </head> > . > . > . > </html> > > Which brings us to the point that I think we need to clarify; what if > I wrote this: > > <head instanceof="[foaf:PersonalProfileDocument]"> > <title>My profile</title> > <meta property="dc:creator" content="John Doe" /> > </head> > > In our current rules this would generate a new bnode for <head>, and > the dc:creator property would apply to that, which I don't think is > desirable. But if we were to make it a little more explicit that the > 'identity' of <head> is the current document, unless overridden > *explicitly* by @about, then my rdf:type use-case falls out quite > neatly to the following mark-up: > > <html > xmlns="http://www.w3.org/1999/xhtml" > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > <head instanceof="[foaf:PersonalProfileDocument]"> > <title>My profile</title> > </head> > . > . > . > </html> > > I think that's actually quite clear from the point of view of what an > author is trying to do, and it has also exposed that we might need to > say a little more about what happens with the <head> element. > > What do you think? > > Regards, > > Mark > > > > On 01/10/2007, Ivan Herman <ivan@w3.org> wrote: > > Hm. You won't like me, but I am not sure I like it:-) > > > > Though is see the rationale, we create some sort of an odd case. At the > > moment the agreement is that a @rel value without a CURIE prefix is > > considered to be in > > > > http://www.w3.org/1999/xhtml/vocab# > > > > and that is it. This is a very clear and easy-to-follow rule. What you > > propose is that, well, this is true, _except_ for the value of > > instanceof that behaves differently. I am not sure it is good if we > > begin to introduce such exceptions. > > > > Or did I misunderstand you? > > > > A possible way out is to say that the 'rdf:' prefix (and probably the > > 'rdfs:' prefix) will always be added to the result of an RDFa processor > > with the usual values. This is not very nice either, but I would prefer > > to solve your problem that way... > > > > > > Ivan > > > > Mark Birbeck wrote: > > > Hello all, > > > > > > Whilst considering RDFa use in the wild, it occurred to me that > > > constructs like the following would almost certainly become quite > > > common: > > > > > > <html > > > xmlns="http://www.w3.org/1999/xhtml" > > > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#" > > > > > > > <head> > > > <title>My profile</title> > > > <link rel="rdf:type" resource="[foaf:PersonalProfileDocument]" /> > > > </head> > > > . > > > . > > > . > > > </html> > > > > > > If the author wants to avoid having to include the RDF namespace, they > > > would have to change their mark-up to look something like this: > > > > > > <html > > > xmlns="http://www.w3.org/1999/xhtml" > > > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > > > > > <head> > > > <title>My profile</title> > > > </head> > > > <body about="" instanceof="foaf:PersonalProfileDocument"> > > > . > > > . > > > . > > > </body> > > > </html> > > > > > > However, if we added an additional link type, such as 'a' or > > > 'instanceof', we could also allow the following mark-up: > > > > > > <html > > > xmlns="http://www.w3.org/1999/xhtml" > > > xmlns:foaf="http://xmlns.com/foaf/0.1/" > > > > > > > <head> > > > <title>My profile</title> > > > <link rel="instanceof" resource="[foaf:PersonalProfileDocument]" /> > > > </head> > > > . > > > . > > > . > > > </html> > > > > > > This avoids the need to declare the RDF namespace, and keeps the > > > metadata in the head of the document which seems more appropriate for > > > this particular kind of statement. > > > > > > 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 > > > > > > > -- > Mark Birbeck, formsPlayer > > mark.birbeck@formsPlayer.com | +44 (0) 20 7689 9232 > http://www.formsPlayer.com | http://internet-apps.blogspot.com > > standards. innovation. > >
Received on Monday, 1 October 2007 12:18:43 UTC