- From: Shane McCarron <shane@aptest.com>
- Date: Thu, 02 Dec 2010 06:45:19 -0600
- To: Ivan Herman <ivan@w3.org>
- CC: Mark Birbeck <mark.birbeck@webbackplane.com>, Toby Inkster <tai@g5n.co.uk>, W3C RDFa WG <public-rdfa-wg@w3.org>
I think the attributes should be processed in DOM order, and that @profile is the exception, not the rule. DOM order would also be consistent with xmlns:a=something xmlns:a=something else. But this is definitely NOT editorial - which is why I think it needs to be a formal last call issue. On 12/2/2010 6:33 AM, Ivan Herman wrote: > Mark, > > to be absolutely honest with you: I do not care. This is a typical edge case; no author in his/her able mind would do this anyway. But an implementation has to know, so we need a resolution. If we want to make use a virtual coin, that can also work... > > Ivan > > > > On Dec 2, 2010, at 13:14 , Mark Birbeck wrote: > >> Hi Ivan, >> >> I guess in one sense left-right v. right-left doesn't make much >> difference. However, our processing rules generally have a sort of >> 'later overrides earlier' aspect to them, based on the hierarchical >> nature of the documents that we're parsing. Having a rule where the >> deeper nodes override their parents' values makes processing very >> easy. >> >> Now, of course you could say that 'latest wins' would still be the >> rule inside the @prefix attribute if we processed from right to left. >> But I do think that would be a little odd, given that conventionally >> people see the DOM hierarchy as going from left to right. >> >> To illustrate, our processing model would say that the second >> occurrence of 'foaf' in this example applies due to the hierarchy (in >> a sense, it's 'later overrides earlier'): >> >> <div prefix="foaf: http://blah1"> >> <div prefix="foaf: http://blah2"> >> <!-- use blah2 ---> >> </div> >> </div> >> >> Writing an example where the same prefix is defined in @prefix might >> look like this: >> >> <div prefix="foaf: http://blah1 >> foaf: http://blah2"> >> <!-- should really use blah2 ---> >> </div> >> </div> >> >> I think it would be counterintuitive if the left-most prefix was >> preferred over the right-most one, in this example. >> >> This simplicity of overriding is lost in the processing of profiles >> (as a result of the resolution you refer to on ISSUE-23). The way that >> the processing is now described in section 9 implies that you need to >> track each profile loaded to see if there is a conflict later. Of >> course, the easiest way to implement this is to process from right to >> left, which removes the need to track each profile, but then I think >> most implementers will rightly ask...why is everything else going from >> left to right, except @profile? >> >> We know that the only reason profile processing was made to work from >> right to left was due to the legacy use of @profile, in which only the >> first value had significance; some argued that this implied that the >> left-most profile should be the most important, and therefore should >> override others. >> >> Personally, I didn't find this very convincing (and the resolution >> didn't have great support), but we have the resolution now. >> >> However, given that we have the resolution to deal with a legacy >> issue, it should really be regarded as an anomaly, I it certainly >> shouldn't be used as a model for other processing rules. >> >> Regards, >> >> Mark >> >> >> On Thu, Dec 2, 2010 at 9:56 AM, Ivan Herman<ivan@w3.org> wrote: >>> Shane, >>> >>> there is no separate comment list; the reference in the document for comments is the WG mailing list... >>> >>> But yes, this _is_ a last call comment, though I thought it is an editorial issue. >>> >>> So, to make it clear, the question is what is the effect of @prefix="a: http://a.b a: http://c.d". In my original mail I said it should be left to right. But I since seemed to remember that we decided to have it right to left, ie, in my example, the result should be a->http://a.b. I tried to find a resolution in the mail archives, but I could not. However I did find this: >>> >>> http://lists.w3.org/Archives/Public/public-rdfa-wg/2010May/0123.html >>> >>> which led to a discussion thread on the relative priority within a @profile. This led to this resolution: >>> >>> http://www.w3.org/2010/02/rdfa/meetings/2010-06-03#resolution_7 >>> >>> ie, left-most declaration wins. I have not found any resolutions related to @prefix. However, based on the the resolution we have already taken for @profile I would propose to define the same order for @prefix and that should be documented in RDFa 1.1 Core >>> >>> Ivan >>> >>> >>> >>> >>> On Dec 2, 2010, at 02:01 , Shane McCarron wrote: >>> >>>> Since we are in last call, please submit this as a last call comment to the appropriate public list before the deadline. >>>> >>>> On 12/1/2010 6:16 PM, Toby Inkster wrote: >>>>> On Wed, 1 Dec 2010 11:21:55 +0100 >>>>> Ivan Herman<ivan@w3.org> wrote: >>>>> >>>>>> @prefix="a: http://a.b a: http://c.d" >>>>>> >>>>>> will end in a->http://c.d >>>>>> >>>>>> However, I tried to locate this in the document and I could not... >>>>> That's what I do, but I agree we need to make this explicit as it's a >>>>> case that implementors will definitely need to handle. >>>>> >>>> -- >>>> Shane P. McCarron Phone: +1 763 786-8160 x120 >>>> Managing Director Fax: +1 763 786-8180 >>>> ApTest Minnesota Inet: shane@aptest.com >>>> >>>> >>> >>> ---- >>> 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 >>> >>> >>> >>> >>> >>> > > ---- > 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 Thursday, 2 December 2010 12:46:12 UTC