2.4 Defining the interface

2.4.1 Generating stub, skeleton, protocol code from IDL

There are two ways of generating the stub, skeleton, and protocol code for a CORBA application. We can either run the IDL compiler on the command-line, or we can run it within the Functional Developer development environment. The second option is more convenient given that we are already using the environment.

: 1. Go to the project window for the My-Hello-World-Client project.

Simply building the project in the normal way is enough to invoke the IDL compiler. This convenience is thanks to the spec file in the project Sources list: when the build gets to the spec file, the build system looks in it to see what to do with it. The spec file in My-Hello-World-Client states with the Origin: and Idl-File: keywords that there is a OMG IDL file to compile, and with the Stubs: keyword that a project containing client stub code should be generated.

If we build My-Hello-World-Client now, the IDL compiler will read the IDL file and create the stubs code. Meanwhile the rest of the Dylan code in the project is also compiled.

: 2. Select Project > Build from the project window's menu.

The spec file in My-Hello-World-Server is similar, but asks for skeletons instead of stubs.

: 3. Select Project > Build in the My-Hello-World-Server project window.

After the build, each project's Sources page is updated to include new subprojects. The subprojects are as follows.

In the client project:

My-Hello-World-Stubs
: The stubs project contains implementation glue code that enables a client application to call a CORBA object in a server application over a network, using a Dylan protocol generated from the IDL.

In the server project:

My-Hello-World-Skeletons
: The skeletons project contains implementation glue code that enables server applications implementing CORBA objects to be called over a network by the Dylan protocol functions generated from the IDL.

In addition, a protocol subproject appears in both the stubs and the skeletons projects:

My-Hello-World-Protocol
: The protocol project contains open classes and generic functions, representing the spirit of the IDL declarations in Dylan. It is used in clients to call operations on CORBA objects in a server, and in a server as the basis of the implementation of those objects.