Re: @profile in XHTML+RDFa 1.1

I tend to go the other way -- I quite like the idea of treating 'head'
in a special way.

For me, 'head' in HTML has always been about the metadata for the
document, with a separation between head and body.

Unfortunately, seeing the world through XML glasses means that this
structure has been 'flattened', and now head is no more significant
than body, which in turn is no more significant than a div or span.

(That's why @profile is on 'head' in HTML 4 -- in an XML world you'd
put it on 'html'.)

I think the semantics of head and body really are different to those
of a div or a span, and there are advantages to treating them
accordingly. For example, head could be regarded as providing
information to help parse body, and therefore would be parsed first;
all profiles would then be fully loaded before parsing body.

(One way to look at it is that 'head' initialises all of the context
information that is set at the top of the RDFa parsing algorithm.)

Regards,

Mark

On Wed, Apr 21, 2010 at 4:31 PM, Shane McCarron <shane@aptest.com> wrote:
> Yeah... I am not wild about having special rules for anything in head
> either...  But I see Toby's (implied) point that @profile is only legal on
> head in HTML4, so people are used to putting it there.  That's the
> disadvantage of reusing an existing attribute, even though there is clearly
> a lot of overlap between our use of @profile and the use of @profile
> described in HTML4.
>
> Ivan Herman wrote:
>
> To be honest I do not remember the details of the discussion... But you are
> right. Let me withdraw the 'mistake' remark:-)
>
> Toby's proposal is a little bit different, though (unless I misunderstand
> him). Toby, do you propose that if I say
>
> <html>
>   <head profile="http://bla">
>     ...
>   </head>
>   <body>
>
>     ...
>   </body>
> </html>
>
> Then the effect of the http://bla profile is also valid in the <body>? So
> this is reminiscent of the treatment of <base> insofar as an element within
> the <head> has an effect over the whole document. This breaks the clean
> model of using the XML tree structure.
>
> We did not have a choice with <base>; that is inherited from HTML. I am not
> sure doing something similar for another attribute would really be a good
> idea. If we do it for @profile, we may also want to do it with @vocab...
> Also, if I put an explicit @about into the <head> that does _not_ affect the
> <body>, so there would be some inconsistency, too.
>
> Cheers
>
> Ivan
>
> On Apr 21, 2010, at 16:31 , Mark Birbeck wrote:
>
>
>
> Hi Ivan,
>
>
>
> (I personally happen to think that giving this separate treatment to <head>
> is a mistake. But that may only be me.)
>
>
> I'm pretty certain it was you who spotted that if you did this:
>
>  <html typeof="foaf:Document">
>
> or this:
>
>  <head typeof="foaf:Document">
>
> you would end up with a bnode as the subject of all of the triples in the
> head.
>
> (I'm not blaming you -- it was an important observation!)
>
> By having an implied @about value we ensure that the triples in the
> head always refer to the current document.
>
> I wouldn't claim it is perfect, but I don't recall anyone coming up
> with a better solution.
>
> We could of course ban @typeof from head, but we've tended to avoid
> those kinds of draconian approaches.
>
> 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/
> mobile: +31-641044153
> PGP Key: http://www.ivan-herman.net/pgpkey.html
> FOAF: http://www.ivan-herman.net/foaf.rdf
>
>
>
>
>
>
>
> --
> Shane P. McCarron                          Phone: +1 763 786-8160 x120
> Managing Director                            Fax: +1 763 786-8180
> ApTest Minnesota                            Inet: shane@aptest.com
>
>

Received on Wednesday, 21 April 2010 15:50:27 UTC