- From: Ivan Herman <ivan@w3.org>
- Date: Sat, 10 May 2008 19:04:55 +0200
- To: Mark Birbeck <mark.birbeck@x-port.net>
- CC: Shane McCarron <shane@aptest.com>, public-rdf-in-xhtml-tf@w3.org
- Message-ID: <4825D5B7.9020902@w3.org>
Hi Mark, I hope XTech was worth your time... I also remember these discussions, ie, to make it clear, I do not have any problem with the original intention... just let us try to minimize the changes in the text:-) See you soon in San Jose, I guess... I. [1] http://lists.w3.org/Archives/Public/public-rdf-in-xhtml-tf/2008May/0062.html Mark Birbeck wrote: > Hi all, > > Sorry for the delay in providing some input, but I've been at XTech this week. > > Shane is definitely correct that the *intention* was that unrecognised > @rel/@rev values should not affect processing in any way, but no > triples should appear in the *default* graph. > > Recall that we have agreed for a long time now that unrecognised > values could appear in other graphs, so we certainly don't want to > mess up processing. > > For example, let's say that we have this: > > <div about="#ivan"> > <div rel="foaf:knows"> > <div about="#ben" rel="foaf:knows" resource="#shane"></div> > </div> > </div> > > We know that this means that Ivan knows Ben, who knows Shane. > > Now, if we add something from another vocabulary--perhaps the XFN > microformat--the intention is that the parser is free to put those > into another graph if it wants to: > > <div about="#ivan"> > <div rel="foaf:knows met"> > <div about="#ben" rel="foaf:knows met" resource="#shane"></div> > </div> > </div> > > So that's the first point; when I used language like "should act is if > it's not there", this is the effect I wanted to achieved. > > Now, let's remove the first FOAF value: > > <div about="#ivan"> > <div rel="met"> > <div about="#ben" rel="foaf:knows met" resource="#shane"></div> > </div> > </div> > > We still want the *default* graph to contain 'Ben knows Shane', so we > certainly don't want to stop processing when we hit the @rel="met". > (Some other graph might also contain 'Ivan met Ben, who met Shane', > but that is processor-specific; we decided before that the default > graph should *not* contain that.) > > Finally let's remove the second FOAF value: > > <div about="#ivan"> > <div rel="foaf:knows met"> > <div about="#ben" rel="met" resource="#shane"></div> > </div> > </div> > > We still want the first triple about Ivan knowing Ben to be completed, > even if there is nothing in the default graph about Ben meeting Shane. > (As before 'Ben met Shane' could be in some other graph, though.) > > Whilst I don't think everything I have just described is explicit, I > think I could definitely back it up from discussions we've had (and > Shane is also saying that he thinks this was the intent). > > So the question should hopefully be only about the amibiguity, and I > think it arises in the phrase that Ivan and Shane have drawn attention > to, about a "valid @rel or @rev"; I think Ben pointed out that this > should really just be about the *presence* of @rel and @rev, rather > than what it contains, since a processor is free to handle values that > are not in our spec, as long as they don't appear in the default > graph. > > So I'll look at proposing some wording. > > Regards, > > Mark > > 2008/5/9 Shane McCarron <shane@aptest.com>: >> >> >> Ivan Herman wrote: >> >>> Shane, >>> >>> I am not sure that step 10 is relevant in our discussion. What I mean is: >> step 10 is of course valid, but what it says is that it would complete those >> triples with [new subject] (if non-null). [new subject] is established in >> steps 4 or 5, depending on whether @rel/@rev have a valid URI set or not. >> I agree that step 10 is not relevant to this discussion. I was conflating >> two issues. Sorry! >> >> >>> Back to the previous issue... Ie, I am sorry, I still do not believe my >> interpretation is wrong...:-( >>> I tried to look at the possible changes if we want to achieve what Ben >> asks for. Here is one way, maybe: >>> #4 comes into effect if _no_ @rel/@rev are present, regardless of whether >> the value is valid or not >>> There is a #4a which comes into effect if @rel/@rev is present but they >> contain no valid URI-s; in which case the [new subject] is set to @about or >> a new BNode >> I believe this is what Mark intended, and it enables the (edge) case that >> you can stop chaining by inserting an empty rel, which was something we had >> discussed at one time. >> >> >>> #5 comes into effect otherwise >>> >>> Hm. Is such a change editorial or does it send us back to LC2? >>> >> I think it is certainly editorial. I am not certain that it makes Ben or >> Mark happy though. I personally don't care what the answer is. I would >> also be happy with changing text in section 5.4.3 by adding to the end of >> the conditions "Regardless of the datatype of the attribute, if evaluation >> of the attribute value for CURIEs and URIs results in no valid URIs, a >> conforming processor MUST behave as if the element has no specification of >> the attribute (e.g., as if there is no entry for the attribute in the DOM >> tree at all)." >> >> -- >> 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/ PGP Key: http://www.ivan-herman.net/pgpkey.html FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Saturday, 10 May 2008 17:05:18 UTC