External Action Blocks › How EABs are Created › Create External Action Logic

Create External Action Logic

You can create logic for an EAB in the following ways:

• 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 generated stub.

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

You can write EAB code in any language. Specific requirements exist, however, for the action block name and the order of parameters passed to and from the generated load module.

The generated load module passes the following parameters to the EAB interface routine. The parameters are passed in the following order:

For C with High Performance View Passing

Follow these steps:

1. IEF-RUNTIME-PARM1
2. IEF-RUNTIME-PARM2
3. PSMGR-EAB-DATA (null array)
4. w_ia (import view C)
5. w_oa (export view C)

Note: For more information about High Performance View Passing, see the Host Encyclopedia Construction User Guide or the Toolset Online Help.

For C Without High Performance View Passing

Follow these steps:

1. IEF-RUNTIME-PARM1
2. IEF-RUNTIME-PARM2
3. w_ia (import view C)
4. w_oa (export view C)
5. PSMGR-EAB-DATA (null array)

IEF-RUNTIME-PARM1 and IEF-RUNTIME-PARM2

Identifies the first two parameters passed from the 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.

w_ia and w_oa

Identifies the position of the import and export views () for C language depending on whether High Performance View Passing is used (see the previous table).

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

PSMGR-EAB-DATA

Identifies an array set to zeroes (null array). For target system implementation, this array is passed but not used (the array is used for IMS and CICS applications on the mainframe).

Note: For more information about the use of PSMGR-EAB-DATA, see the Host Encyclopedia Construction User Guide.

Note: For component development, High Performance View Passing must be set on for both the component and the consuming model.

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.

Note: Each attribute field in the data structures must be preceded by a one-byte field defined in C as char. This one-byte field contains a value that must not be changed.

Modify the stub using any editor that can save files in the appropriate character set format. The modified stub cannot contain any control codes or header information unique to the editor.