18.3.1 Starting a DDE server

To provide a LispWorks application with a DDE server, follow the following three steps.

1. Define a specialized Lisp DDE server class using define-dde-server. Here the server class is called foo-server and it has the service name " FOO ":

(define-dde-server foo-server "FOO")

2. Provide the server class with the functionality it requires by specializing methods on it and/or using define-dde-server-function. Here the server function is bar , which takes a string as an argument, and prints this to the standard output. For convenience, the system topic is used, though usually it is better to define your own topic.

(define-dde-server-function (bar :topic :system)

    :execute

    ((x string))

  (format t "~&~s~%" x)

  t)

3. Start an instance of the server foo-server using start-dde-server.

(start-dde-server `foo-server)

This function returns the server object, which responds to requests for conversations with the service name " FOO ", and accepts execute transactions for the function bar in the " System " topic.