OME::Remote - the OME Remote Access API
OME::Remote::Dispatcher
OME::Remote::Prototypes
OME/SOAP/StandaloneServer.pl
The Remote Access API is currently very experimental. Use it at your own risk.
The classes in OME::Remote allow developers to access the OME API from languages other than Perl, by providing an interface to the API over an RPC protocol. The Remote Access framework has been written to be independent of the specific RPC protocol involved; we have experimented with both SOAP and XML-RPC. The XML-RPC server seems to interact better with other clients.
The OME::Remote::Dispatcher object is responsible for translating received RPC calls into the appropriate Perl API calls. All method calls are executed in the context of an OME session. All objects created by the Perl methods are serialized into the RPC messages as object references; the objects themselves are kept in a cache on the server side. This has two benefits: First, the objects maintain their integrity even in the absence of object-oriented method call support in the RPC protocol (i.e, XML-RPC). Second, this enforces object encapsulation across the RPC channel, adding a small extra layer of security. Malevolent and/or buggy user code cannot create and modify objects to trick the Remote Access server into doing something that it shouldn't; Remote Access clients only have access to Perl objects explicitly created by the methods of the Perl API.
Please see OME::Remote::Dispatcher for more information.
The methods in the Perl API which are accessible via the Remote Access server are specified in the OME::Remote::Prototypes class. This allows us to prevent certain methods from being available to remote clients, and also provides a better type-checking facility than is provided by Perl itself.
Please see OME::Remote::Prototypes for more information.
The StandaloneServer.pl script is the executable that starts the RPC daemon used by the Remote Access layer. It runs as a foreground process, and can listen on a non-privileged port, allowing the script to be run by a normal user. It also can be configured to act as either a SOAP server or an XML-RPC server. In either case, it publishes the methods in the OME::Remote::Dispatcher class.
perl StandaloneServer.pl <port number> <"SOAP" or "XMLRPC">
where <port number> is the TCP port to bind the RPC server to, and the second parameter determines whether the script will start a SOAP server or an XML-RPC server. The script will display on STDOUT the URL to connect RPC clients to.
In the case of the SOAP server, the OME::Remote::Dispatcher methods are served out of the OME/Remote/Dispatcher namespace. For the XML-RPC server, the methods are served out unqualified.
Douglas Creager (dcreager@alum.mit.edu)