Re: What do you get when you dereference the URI of a named graph?

On 2012-01 -04, at 10:42, Yrjana Rankka wrote:

> 
> Let's consider this situation:
> 
> GRAPH <x>
> <s1> <p1> "val1";
> <p2> "val2";
> <p3> "val3".
> 
> GRAPH <metadata>
> <x> dc:created "somedate";
>        dc:modified "someotherdate";
>        dc:creator "Zaphod Beeblebrox".
> 
> A client dereferences <x>
> 
> What would you expect to get?

Typically, I would expect

1) You would get the triples in the graph when you dereference <x.n3> .

2) You would get an HTTP header pointing to the metadata -- try it below:

$ curl -I http://www.w3.org/2012/04/x.n3
HTTP/1.1 200 OK
Date: Wed, 04 Jan 2012 21:14:32 GMT
Server: Apache/2
Last-Modified: Wed, 04 Jan 2012 21:09:24 GMT
ETag: "2d-4b5ba3aed0900"
Accept-Ranges: bytes
Content-Length: 45
Cache-Control: max-age=21600
Expires: Thu, 05 Jan 2012 03:14:32 GMT
P3P: policyref="http://www.w3.org/2001/05/P3P/p3p.xml"
Link: metadata.n3;rel=meta
Connection: close
Content-Type: text/n3; qs=0.89

3) You would get the metadata triples when and if you look up the separate
<metadata.n3> resource.

In the client quad store, what rdflib.js does for its provenance column
it to associate the triples in one graph with the documents you would expect

<x.n3> log:semantics {
<s1> <p1> "val1";
<p2> "val2";
<p3> "val3".
}.

and 
<metadata.n3> log:semantics {
	<x.n3> dc:created "somedate";
	       dc:modified "someotherdate";
	       dc:creator "Zaphod Beeblebrox".
} .

There is also another triple generated which links the two resources,
and its provenance (in tabulator for example) is recorded as the 
network access event.  I append a bit of tabulator triple store dump
with -> standing for log:semantics as a PS.

TimBL





> 
> Cheers,
> 
> -- 
> Mr. Yrjana Rankka        | ghard@openlinksw.com
> Developer, Virtuoso Team | http://www.openlinksw.com
>                         | Making Technology Work For You
> 
> 
> 

_________________________________________________________

PS: 

[ <http://www.w3.org/2000/01/rdf-schema#label>
   "[16:53:13]  Request for http://www.w3.org/2012/04/x.n3";
<http://www.w3.org/2007/ont/link#requestedURI>
   "http://www.w3.org/2012/04/x.n3";
<http://www.w3.org/2007/ont/link#response>
   _:n38;
<http://www.w3.org/2007/ont/link#status>
        (    "[16:53:13.225] HTTP Request sent."
           "[16:53:13.380] N3 parsed: 3 statements in 0 lines."
           "[16:53:13.380] done" ) ].



_:n38 -> { 
[ <http://www.w3.org/2007/ont/http#status>
   "200";
<http://www.w3.org/2007/ont/http#statusText>
   "OK";
<http://www.w3.org/2007/ont/httph#accept-ranges>
   "bytes";
<http://www.w3.org/2007/ont/httph#cache-control>
   "max-age=21600";
<http://www.w3.org/2007/ont/httph#connection>
   "close";
<http://www.w3.org/2007/ont/httph#content-length>
   "45";
<http://www.w3.org/2007/ont/httph#content-type>
   "text/n3; qs=0.89";
<http://www.w3.org/2007/ont/httph#date>
   "Wed, 04 Jan 2012 21:53:13 GMT";
<http://www.w3.org/2007/ont/httph#etag>
   "\"2d-4b5ba3aed0900\"";
<http://www.w3.org/2007/ont/httph#expires>
   "Thu, 05 Jan 2012 03:53:13 GMT";
<http://www.w3.org/2007/ont/httph#last-modified>
   "Wed, 04 Jan 2012 21:09:24 GMT";
<http://www.w3.org/2007/ont/httph#link>
   "metadata.n3;rel=meta";
<http://www.w3.org/2007/ont/httph#p3p>
   "policyref=\"http://www.w3.org/2001/05/P3P/p3p.xml\"";
<http://www.w3.org/2007/ont/httph#server>
   "Apache/2" ].
 }.