[MOBY-l] Update from the last developers meeting: MOBY-S API changes

[Mark Wilkinson]

Hi all, 

I am finally getting around to writing the update from our last
developers meeting, hosted by Lincoln at CSHL.  Thanks Lincoln!

Well, the whisky and ideas flowed like a river :-) and as a consequence
there were some important decisions made affecting the MOBY-S API:

(1)  The process of registering and deregistering a service will now
become more of a "pull", rather than a "push"; your server will now host
a simple RDF document that describes your service such that MOBY Central
can GET this document on a regular basis to decide if your service is
still registered and/or modified.  Thus we don't need any fancy security
model for deregistration, since presumably only you have access to your
own server.  This is quite Google-like.

(2)  The messaging XML format has changed slightly:
	(a) the moby:Query and moby:Response tags have now been merged into a
single tag moby:mobyContent
	(b) the moby:queryInput and moby:queryResponse tags have now been
merged into a single tag moby:mobyData
	-- these two changes now make the input message structure ~identical to
the output message structure, thus we truly can pipe messages from one
service to the next without fiddling with them.

Change #1 has not yet been implemented, and might take a while.  I'll
try to make some progress on it this weekend.  The idea is that you will
register your service using the existing registerService API call as
usual, with the inclusion of one additional parameter representing the
location where you will store your service description RDF documents for
MOBY Central to GET.  MOBY Central will parse your registerService call
and return you a registration Object as usual, however the registration
Object will contain an additional parameter, representing the RDF
document that describes your service as per the parameters you sent it -
i.e. MOBY Central will create the RDF for you.  You place the RDF in the
location that you indicated in the registerService call and MOBY will
troll your server every ~week to see if it is still there, and update
the registry if it has changed.

Change #2 will be implemented in the Perl libraries (e.g.
MOBY::Client::Central and MOBY::CommonSubs), and hopefully also in the
Java libraries, thus people using the libraries to create/parse the
messages should not notice the change... so if you are not using the
libraries, you should be! :-)  I'm trying to ensure that both message
structures are understood by these libraries so that we continue to have
backward compatibility at least for a while.

I'm going to update the API documentation on the web ASAP.

I'll put the photo's from the meeting up on the web as soon as they have
been edited for content...  ;-)  ;-)

Cheers all!

Mark

-- 
Mark Wilkinson (mwilkinson at mrl.ubc.ca)
University of British Columbia iCAPTURE Centre