- From: José Manuel Cantera Fonseca <jmcf@tid.es>
- Date: Thu, 24 May 2007 13:20:54 +0200
- To: Keith Alexander <keithalexander@keithalexander.co.uk>
- Cc: public-rdf-in-xhtml-tf@w3.org, public-grddl-comments@w3.org
+1 for all your comments, excellent post I would add that getting rid of the profile attribute in the head element is no problem. You can always use link rel="profile", even, I would say that rel="profile" is a more orthogonal mechanism than an specific attribute. Best wishes Keith Alexander escribió: > > Elias Torres wrote: > > Hi, >> >> In short, I don't think profile urls work because not everyone uses them >> (point in case microformats). > This is a similar rationale to what appears to be HTML 5's decision to > drop the @profile. I'm thoroughly unconvinced by it. A profile, or > lack of one, doesn't stop a consumer from trying to parse the page for > RDFa or microformats, or eRDF or anything else, but the presence of > one does let an author state unambiguously how their document can be > interpreted. Some consumers may want to take a liberal attitude, and > have a stab at anything it comes across, but others will not want to > bother unless they are sure the page contains RDFa. > > For example, I've got a grease monkey script that lets me know if the > page I'm on contains eRDF. It just looks for the profile, because I > don't want the performance lag of looking for other indicators that > eRDF is being used, and in this situation, I'd rather err on the side > of performance and chance missing some eRDF without a @profile, than > slow down the browser (and possibly be bothered by false positives). I > can't do that with RDFa if there's no way of indicating that the page > contains RDFa or not - so I have to run it all through the RDFa parser > and see what comes out? >> Therefore, to depend on it to find RDFa >> would be misguided. There are other practical issues, such as limited >> access authors/publishers that don't have control over the head section >> of the page. > Again, offering a profile for authors to use doesn't prevent users of > CMSs etc from writing RDFa - it just lets those who /do/ have control > use it to be unambiguous about what they mean. > I think it's unnecessary to be shutting down options at the moment, > especially given that adoption of data-in-html techniques is only just > beginning to gain ground with mainstream authors and developers. > > CMS's will adapt if there is demand, and other methods for flagging > RDFa content outside of the head could be offered - perhaps something > like *[@rel="profile"] would not be too horrible a workaround? >> This violates one of our principles of copy and paste/drag >> and drop. It would require copying the profile and enabling on the page >> you pasted it, hence making it more cumbersome that copy and paste >> alone. >> >> > Copying and pasting is an activity that involves a human looking at > the data before and after the operation, and will be able to spot if > something is amiss, so the presence or absence of a @profile is not > important here. > > But for other applications, where machines have to interpret without > human guidance, a @profile could be very useful indeed. >> We want metadata to be first class in (X)HTML and not depend on special >> codes to tell us if there's metadata. > HTML (I'd argue) isn't really suited for being a candidate for > treating data as a first class citizen, because its primary use is for > presenting documents (not units of data) to humans. And when you > create a human-readable document (like a web page) from machine > readable data, you generally have to do some formatting to make it > palatable to the humans. And if you want to provide a machine > readable version of human readable information, you have to somehow > embed that machine readable data in your html in a way that won't > frighten the humans. There's a slight mismatch here, illustrated by > the accessibility problems caused by microformats' abbr[@title] > pattern. Perhaps XHTML 2's @content will help make this cleaner, I > don't know (I've not been able to find out what screenreaders etc are > supposed to do with it), but it doesn't solve it entirely; you still > have to provide the information twice, and you can't, for instance, > stuff XML fragments into an attribute. > > HTML data formats are a useful technique, but they are inevitably a > compromise. > > I think the heart of my disagreement with this attitude towards > @profile, is that you obviously want *RDFa* to be in First Class, and > all *other* methods of embedding data in html to lump it in Third - > which is pretty much the same impression I get with regards to HTML > 5's attitude to microformats. > > And that's disappointing because there isn't one syntax that's going > to be best for everyone all of the time, and there doesn't have to be > a 'winner' - publishers should be able to say whether they're using > RDFa, and user-agents should be able to decide whether to ignore an > absence of a profile or not. HTML is supposed to have a doctype, but > that doesn't stop browsers from trying to parse as html anything that > looks like it. >> (X)HTML already has semantic >> features which authors can use to express their meaning such as h1, h2, >> lists, links, meta, rel, rev, etc. Therefore, all pages have metadata, >> we are just adding richer capabilities. >> >> > That's not really convincing because the 'semantics' of html elements > are of a different nature from the semantics of RDFa. You aren't > *just* extending HTML's semantics, you're extending it to allow a > different *kind* of semantics to be embedded in it - the semantics, > incidentally, of a data model that can be expressed in many > different ways. So it would be good if RDFa could 'play nice' with > some of those other ways. > > I apologise for making my first post to this list one of dissent, and > I'm sorry if I'm irritating you all about an issue that has already > been laid to bed, I just think that offering at least the *option* of > a @profile to authors is important. It doesn't stop anyone from using > or parsing RDFa without it, it just acknowledges that not every web > page contains RDFa, and that RDFa isn't the only syntax for expressing > RDF in HTML. > > Thanks, > > > Keith >
Received on Thursday, 24 May 2007 12:26:49 UTC