Summary
FRM095 - Calling a Function
Important Observations
- Functions are called locally using the CALL command. The CALL can pass a working list into the called function.
- The called function must have a RCV_LIST() defined on its FUNCTION statement
- Passed working lists must be identically defined, in caller and called function.
- The EXCHANGE command enables an "exchange list" of fields to be passed into the called function.
- A called function uses EXCHANGE to return fields to the caller.
- Remote functions running on the server are called using CALL_SERVER_FUNCTION
- The CALL_SERVER_FUNCTION can handle passing and returning working lists and the fields exchange list.
Tips & Techniques
- In a real application, the client/server connection would normally be established by a "connect" form at the start of the application.
- In this example we depended on the Visual LANSA IDE to start the connect to server.
What You Should Know
- How to CALL a function
- How to use the EXCHANGE command to pass field values into a called function
- How to use CALL_SERVER_FUNCTION