[MOBY-dev] API finally RDF-ized to what we decided on at the last MOBY meeting

[Mark Wilkinson]

Hi all, 

between Nina and I we have now come fairly close to a working
~distributed model for service registration/deregistration/updates, as
we had decided at the CSHL MOBY Meeting.

Here's the way it works:

There is a new optional parameter in the registerService call -
signatureURL.  In that parameter, you enter the URL that the MOBY
Central agent should look to for an RDF describing your service.  If
your registration was successful, you will receive a Registration
object, as usual, but the registration object now contains an extra
element <RDF> that contains the RDF describing your service signature. 
You should place that RDF at the location you indicated in your
signatureURL.  Nina's agent will come around occasionally and check that
document for any updates/additions, etc.  If the document is removed,
your service will be deregistered.  Any RDF tags present in that
document that are not familiar to MOBY will be ignored - thus you can
annotate your service as much as you wish without affecting the registry
agent.

Services registered with a signatureURL **cannot be deleted by the
deregisterService call!!**, only by the agent.  You can temporarily
register a service by registering it without a signatureURL - the next
time the agent goes exploring, it will delete your service (i.e. it
deletes services if it finds no RDF at the URL, or if there is no URL to
look to)

Once MOBY Central knows your URL, you can add new services without using
the MOBY Central API at all!  Simply add a new signature to the RDF
document, and the agent will register your new service next time it
explores your site.  Of course, if you don't want to write the RDF
yourself (and who would?!?) you can simply use the registerService call
of MOBY Central as usual, and it will return the RDF to you.

In the next few days, I will be setting up a temporary method call to be
used by all existing service providers that will allow you to send a
signautureURL to MOBY Central and retrieve an RDF document for all of
the services you currently have registered, so you will NOT have to
re-register them all! :-)  This will bring the database up to date with
a URL for everyone.

NOTE TO THOSE WITH THEIR OWN MOBY CENTRAL INSTALLATIONS

There is now an extra field in the service_instances table:
         signatureURL  varchar(255)  null is allowed.
You will need to alter your database the next time you cvs update.


Shortly - probably this weekend - I will be sending messages only to
those who have services registered with information on how to retrieve
your RDF signatures.

At the moment, all tests pass, so I think it should be a ~painless
transition.  Lete me know if you experience difficulties.

Best wishes all!

Mark


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