External Action Blocks › Create the Calling Procedure Step or Action Block › Create External Action Logic

Create External Action Logic

The following ways to create logic for an EAB:

• Add a call to an existing subroutine
• Write code for a new subroutine, and add a call to that subroutine in the EAB
• Add logic directly into a CA Gen generated stub

When you use the CA Gen generated stub, much of the work is already done in a format that is acceptable to the CA Gen software.

EAB code can be written in any language that follows LE linkage conventions. The specific requirements exist, however, for the action block name and the order of parameters that are passed to and from the CA Gen generated load module.

For COBOL, the PROGRAM-ID field must be the same as the name, or entry point, of the interface routine that is called in the stub.

The CA Gen generated load module passes the following parameters to the EAB interface routine in the order indicated as follows:

For COBOL with High Performance View Passing

IEF-RUNTIME-PARM1

IEF-RUNTIME-PARM2

PSMGR-EAB-DATA (null array)

w_ia (import view)

w_oa (export view)

IEF-RUNTIME-PARM1 and IEF-RUNTIME-PARM2 are the first two parameters that are passed from the CA Gen generated load modules. These parameters must be coded on the entry statement of the interface routine and must always be passed in this order to any subordinate routines that are called. However, if user code that contains IMS or CICS-specific code is placed directly in the EAB stub these IEF-RUNTIME-PARM parameters are changed. For IMS, the IEF-RUNTIME-PARM parameters are mapped to the IO-PCB and ALT-IOPCB, respectively. If the user code uses the IO-PCB, the ALT-IOPCB, or both, remove the corresponding IEF-RUNTIME-PARM from the LINKAGE SECTION and the PROCEDURE DIVISION USING statement.

For CICS, the IEF-RUNTIME-PARM parameters are mapped to the CICS EXEC Interface Block (EIB) and the COMMAREA, respectively. If the user code uses DFHEIBLK, DFHCOMMAREA, or both remove the corresponding IEF-RUNTIME-PARM from the LINKAGE SECTION and the PROCEDURE DIVISION USING statement. In addition, remove these parameters if the modified EAB is processed by the CICS translator, as the CICS translator automatically includes a reference to DFHEIBLK and DFHCOMMAREA.

Note: High Performance View Passing impacts the order of parameters that are transferred into an EAB. By default, High Performance View Passing is set ON.

For component development, High Performance View Passing must be set ON for the component and the consuming model. The import and export views for COBOL are the fourth and fifth parameters that are passed and are represented as W-IA and W-OA.

The interface routine must contain data structures that correspond exactly to the import and export views of the EAB. The fields in the data structures correspond to attributes in the import and export views of the EAB. Each attribute field in the data structures must be preceded by a one-byte field that is defined in COBOL as PIC X. This one-byte field contains a value that is not changed.

PSMGR-EAB-DATA is an array set to zeros (Null array). For the target system implementation, this array is passed but not used. The array is used for IMS and CICS applications. Modify the stub using an editor that can save files in the appropriate character set format. The modified stub cannot contain control codes or header information unique to the editor.