What is Module Pool Programming and its use?

A module pool can contain all possible declarative statements. All processing blocks are supported except for reporting event blocks and function modules. The module pool supports classic dynpros and selection screens. It can be executed using transaction codes. Module pools are created using ABAP Editor. It is also known as dialog programming. It is a method use in SAP ABAP to create custom SAP application using GUI (Graphical User Interface). It is a special type of programming that creates custom SAP screen based on business requirements.

Tcode:

SE80 : ABAP Development Workbench

SE51 : Screen Painter

SE41 : Menu Painter

SE38 : ABAP Editor

SE93 : TCODE Creation

Key Concepts of MPP:

1. Transaction Code: MPP programs are executed using transaction codes, typically starting with ‘Z’ or ‘Y’.
2. Screen Painter: A tool used to design the user interface.
3. Events:
   • Process Before Output (PBO): Triggered before the screen is displayed.
   • Process After Input (PAI): Triggered after user input is processed.
   • Process On Value Request (POVR): Triggered for F4 help.
   • Process On Help Request (POHR): Triggered for F1 help.

Basic Syntax:

1. Create a Module Pool Program:
2. Define Screens: CALL SCREEN 100.
3. Screen Layout: Use the Screen Painter (transaction SE51) to design the screen layout.
4. Flow Logic:

   PROCESS BEFORE OUTPUT.

   MODULE status_0100.

   PROCESS AFTER INPUT.

   MODULE user_command_0100.

5. Modules:                                                                                  MODULE status_0100 OUTPUT.

     ” Code to set screen status

   ENDMODULE.

   MODULE user_command_0100 INPUT.

     CASE sy-ucomm.

       WHEN ‘SAVE’.

         ” Code to handle save action

       WHEN ‘EXIT’.

         LEAVE PROGRAM.

     ENDCASE.

   ENDMODULE.