An Introduction to Functions › Additional Processing › Linking Functions

Linking Functions

CA 2E automatically links certain functions together. For external update functions, CA 2E automatically links to the database functions that update data. CA 2E also automatically provides the linkage to functions that allow lookup capabilities. You can use action diagrams to specify further links between functions.

For more information on action diagrams, refer to the chapter Modifying Actions Diagrams.

When HLL code is generated to implement several connected internal functions, such as functions that are implemented as inline code, the HLL used to generate the functions is determined by the source type of the external function, which calls the internal function or functions.

If you connect Execute User Source (EXCUSRSRC) functions together with other functions, you must ensure that the connected functions all have the same HLL implementation types (that they are all RPG or all COBOL functions.)

Although CA 2E does not impose any limitation on the recursive linking of external functions, some high-level languages do. For example, the same RPG program may not appear twice in a job's invocation stack. This means that you should avoid having a function calling itself, either directly or via another function.