Work with user defined functions

User-defined functions (often referred to as DID-defined functions) may be considered to be a special, restricted form of Entries. In fact they are basically the same as Entries in almost any aspect. The big difference is that User-defined functions can only return one Record with exactly one Result field.

A User-defined function can best be looked at as the description of the interface of a program (the program execute function). The Input parameters describe the parameters of the program; only input parameters are allowed. The Result field describes the data the program must send back to the ITP Model when it uses the function.

Another major difference between Entries and User-defined functions is that there is no automatic support for creating a User-defined function; everything has to be created manually. User-defined functions are intended to describe a particular kind of service that has to be performed during the ITP Model execution, without the necessity to write down a complete WITH or FORALL construct in the ITP Model document: User defined functions can be used like any other function in the ITP Model development language.

A User-defined function consists of:

• the User-defined function attributes, e.g. the name of the User-defined function, or a descriptive text
• the set of Input parameters
• the Result field
• a reference to an iSeries program

From the panel "Work with User defined functions" User-defined functions can be created, changed, deleted, etcetera.