7.27.3 DEF_MAP_EX and Calling a Procedure in a Service Program

When a DEF_MTH_EX does specify an ENTRYPOINT, it means that the external method being called is a procedure in a service program.

Only a maximum of one DEF_MAP_EX can specify FOR(*RESULT), as there can only be one return value for a procedure in a service program, but there can be none as not every procedure in a service program has a return value.

When a DEF_MAP_EX is used with such an associated DEF_MTH_EX these rules apply:

• The FOR value controls both what is mapped to and from RDML and whether a parameter is passed by value or by reference.

• In the case of *INPUT, the value is mapped from RDML before calling the external method and the parameter is passed by value.

• In the case of *BOTH, the value is mapped from RDML before calling the external method, the parameter is passed by reference and the value mapped back to RDML variables after calling the external method.

• In the case of *OUTPUT, the parameter is passed by reference and the value mapped back to RDML variables after calling the external method.

Important Note

TYPE(*SIGNED) FOR(*INPUT) is not supported. The IBM i operating system does not support C using its equivalent to RPG Signed passed by value to an RPG signed parameter.

Example 1: Define an argument that is a time to be passed in *USA format by value to a procedure

Def_Map_Ex Name(CloseTime) For(*INPUT) Type(*TIME) Format(*USA)

 

Example 2: Define the result value that is a null terminated string of maximum length 999 characters not counting the null terminator for a procedure

Def_Map_Ex Name(Conditions) For(*RESULT) Type(*VARCHAR) Length(999) Format(*NTS)

 

Example 3: Define an argument that is a float that will be passed back from a procedure

Def_Map_Ex Name(Tolerance) For(*OUTPUT) Type(*FLOAT) Length(4)