Syntax

This is the syntax for the SET-CALLBACK-PROCEDURE( ) method:

SET-CALLBACK-PROCEDURE (callback-name, internal-procedure 
              [ , procedure-context ])

The parameters include:

  • callback-name — A character string value of "REQUEST-HEADER" or "RESPONSE-HEADER" to identify the type of callback.
  • internal-procedure — A character expression containing the name of the internal procedure you want executed for the specified callback. To unregister a callback definition, pass an empty string ("").
  • procedure-context — (Optional) A procedure object handle that points to an active procedure context that contains the specified internal procedure. This is typically a persistent procedure instantiated in the current OpenEdge session or the method calling context (THIS-PROCEDURE). If not specified, it is the value of THIS-PROCEDURE.

In general, you can define the internal procedure for a callback in any procedure context that is guaranteed to be active at the time you execute the SET-CALLBACK-PROCEDURE( )method, and that remains active until after the callback procedure is executed by OpenEdge. The time of this execution depends on the type of request:

  • Synchronous Web service requests — For either a SOAP request header callback or a SOAP response header callback, the procedure context must remain active until the operation invocation has completed execution.
  • Asynchronous Web service requests — For a SOAP request header callback, the procedure context must remain active until the operation invocation has completed execution. For a SOAP response header callback, the procedure context must remain active until activation of the PROCEDURE-COMPLETE event for the request and any results have been returned to the PROCEDURE-COMPLETE event procedure.