Daniel Schwabe wrote:
Kingsley , Giovanny, Michael and all,
thanks for the prompt replies.
I didn't express myself properly. I'm looking for a programmatic way
to find the SPARQL endpoint, something analogous to a DNS -> ip
translation. This metaphor breaks down right away, as there is no
centralized service where I can query - this is what I was trying to
emulate with Sindice, by issuing a query for the void:sparqlEndpoint
property, given the dataset's home URL. Hopefully, if there is one,
Sindice would have indexed it.
In our case when you de-reference a URI we include an rdfs:seeAlso link
to an associated VoiD graph URI. The idea being you discover the
endpoint as part of the resource description.
I could query the site for its sitemap extension (would it always be
<home url>/sitemap.xml? doesn't seem so...), as Giovanni suggests, and
see if I get a result; in the affirmative case, I have to parse it and
look for the <sc:sparqlEndpointLocation> element.
As Michael Lang put it, one could have a Dataset Registry, but again I
would want to have a way to query it programmatically. In addition, it
would be a centralized resource.
Hence my suggestion - I am looking for a simple way to enable
autodiscovery. If all sites would agree to make the sitemap.xml
available at <home url>/sitemap.xml, that would work as well. I just
think that a simple naming convention such as <home url>/sparql would
be even easier to implement, and it may become one of those "de facto"
standards if the main datasets follow the convention... (as I said,
many already do...)
I also see utility in complementing what I stated above with the following:
1. "sitemap.xml" in: http://<cname>/sparql/
2. Link hook from <head/> section of http://<cname>/sparql as in:
<link rel="rdfs:seeAlso" type="<content-type>" title="Data Set
Description (VoiD Graph)"
href="<void-graph-info-resource-interface-url>" />
3. A de-referencable URI for VoiD graphs (we just need to agree a URI
pattern for Slash or Hash schemes)
Kingsley
Cheers
D
--
Regards,
Kingsley Idehen Weblog: http://www.openlinksw.com/blog/~kidehen
President & CEO
OpenLink Software Web: http://www.openlinksw.com
