[redland-dev] HTTP interfaces to RDF models

[Danny Ayers]

On 7/7/05, netmeld at netmeld.com <netmeld at netmeld.com> wrote:

> It's not clear to me if there is anything that's evolving
> into a 'standard' protocol.

For read-only querying at least, the SPARQL protocol [1] (scroll past
the XML Schema bits!) seems to be the point of convergence, for
instance see comments re. Joseki [2].

For updates/deletes etc...Dave..?

For what its worth, I've been using a simple bit of bridge code [3,4]
on top of mod_python/Apache2/Debian to access a Redland store over
HTTP. The querying side has been fairly straightforward using SPARQL.
I've only been using SELECT but with XML results passed through XSLT
it's very versatile.

I'm only now getting to the point where I need to be able to
systematically modify the store over HTTP (I've got lots of grubby
little one-off scripts...). I'm hoping a kind of two-phase approach
will work, first do a SPARQL CONSTRUCT to build a graph, then remove
all the statements in the generated graph from the main triplestore
(bnodes may cause problems). Anything that needs to be added can be
passed as RDF/XML in the body of a HTTP post, or by reference to its
URI.
(If anyone's tried this sort of thing already I'd love to hear about
what works and what doesn't ;-)

Cheers,
Danny.

[1] http://www.w3.org/TR/rdf-sparql-protocol/
[2] http://groups.yahoo.com/group/jena-dev/message/16827
[3] http://pragmatron.org/docs/pymplex.html
[4] http://pragmatron.org/docs/sparqlsphere.html

-- 

http://dannyayers.com