[rdfweb-dev] Time's running out?

Julian Bond julian_bond at voidstar.com
Fri Aug 8 22:15:25 UTC 2003


Danny Ayers <danny666 at virgilio.it> wrote:
>I'm not sure about "define a resource for foaf:Person" - with the Jena
>(Java) kit I'd probably load the data in, then look for all resources where
>their rdf:type is foaf:Person,

This is the same, same.

$rdfTypeR = new Resource("http://www.w3.org/1999/02/22-rdf-syntax-ns#", 
"type");
$foafPersonR = new Resource("http://xmlns.com/foaf/0.1/", "Person");

$people = $model->find(NULL, $rdfTypeR, $foafPersonR);

$personIterator = $people->getStatementIterator();
while ($personIterator->hasNext()) {
etc

The key statement is effectively
$people = $model->find(NULL, //Any subject
$rdfTypeR,                   //predicate = rfs:type
$foafPersonR                 //object = foaf:Person
);

There is also $model->findRegex which works on the subject, predicate 
and object labels. But it's easy with this to ignore the namespace names 
and lose the benefit of them stopping tangling. I guess I could search 
for %.*foaf/0.1/Person%

Starting to ramble now...

>I don't understand what you're saying about the indirection, all it should
>do is stop any names getting tangled.

See my last email that overlapped with yours.
 > Oh dear, wrong file.
 > http://swordfish.rdfweb.org/people/libby/rdfweb/libby-foaf.rdf
contains no foaf:person but does contain
<web:Description about="genid:libby"> which seems to be serving the same 
purpose. Working backwards
web="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

Somewhere along the line, Dan (I think) suggested that there are times 
when Person is implied. I made the leap to some sort of indirection.

I'm beginning to think that I'm confusing myself here by trying to work 
with an experimental file that doesn't even validate and everyone else 
has forgotten about.

And I see Libby has just nuked the file...

> Where there
>> are two or more versions with data in the wild, I'll have to iterate
>> over them.

>If there are two or more versions of a persons FOAF file are out there you
>can either choose to ignore the older one,

No. Two or more versions of a namespace not of a persons FOAF file. eg 
if there existed 2002/02/02/rdfs and 2003/03/03/rdfs where the second 
was a superset of the first. Further imagine that some people reference 
the first in their files and some people use the second. I as a 
developer need to search my datastore for both 2002/02/02/rdfs#seeAlso 
and 2003/03/03/rdfs#seeAlso

Perhaps I'm imagining a problem here that doesn't actually exist in the 
wild. Yet. I can't help thinking that namespace versioning becomes a 
problem at some stage.

>I can't be sure not being familiar with RAP, but I suspect your app and
>Ian's aren't asking questions for which there are answers.

Um, "are asking questions for which there are no answers" ?

Enough already. I'm off to bed.

-- 
Julian Bond Email&MSM: julian.bond at voidstar.com
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