parametersopenedgeprogress-4gl

Processing unnamed optional include file parameters in Progress


I'm trying to add a simple IF statement to my include .i-file to handle optional unnamed parameters:

message.i:

/*
    - {1}: Message.
    - {2}: OPTIONAL Sender name
*/
&IF DEFINED({2}) <> 0 &THEN
    {2} = "Unknown sender".
&ENDIF.
MESSAGE "{2}" + ": " + "{1}" VIEW-AS ALERT-BOX.

test.p:

{message.i "hello world" }
// Should output "Unknown sender: hello world".
// Does not compile.

{message.i "hello world" "Michael" }
// Should output "Michael: hello world".

In this version, the message.i will throw error if the second parameter is missing.

I want to use unnamed parameters and avoid the parameter naming.

How I can fix the code to make it work?


Solution

  • You could check if the second parameter is empty :

    message.i

    &IF "{2}" <> "" &THEN
        MESSAGE "{2}" + ": " + "{1}" VIEW-AS ALERT-BOX.
    &ELSE
        MESSAGE "Unknown sender" + ": " + "{1}" VIEW-AS ALERT-BOX.
    &ENDIF.
    

    AblDojo example