Introduction
SAP provides standard transactions to enter data into database. But a client may want to maintain some additional information in SAP other than what is provided.
To make provisions for this, additional screens have to be provided and additional fields must be added into appropriate database table.
To pave way for this, SAP has provided the option for screen exits. Usually, SAP provides the following:
- An append structure in the database table with the new fields.
- A subscreen area into the standard screen – where the programmer can attach his subscreen of his own program with the new fields.
- A function group under which the new subscreen has to be created with the new fields.
- Function exits to synchronize the PBO and PAI of the standard SAP program with the PBO and PAI of the subscreen – so that data can flow back and forth between the standard SAP program and the program written by the developer for the subscreen. These function modules also exist in the same function group under which the subscreen will have to be developed.
Finally, a linkage has to be done between the subscreen area of standard SAP screen with the custom subscreen constructed by the developer.
Typically, SAP provides an enhancement in which the developer can create an append structure, use the function exits to synchronize the PBO and PAI of the standard SAP program and the custom subscreen program, and make the necessary linking( as mentioned above in step 4. But, again, this is not a hard and fast rule. Linking in some case, is also done by configurations.) SAP also usually provides the name of the function group under which the subscreen has to be developed.
Necessary guidance about implementing a screen exit development is usually available in the Documentation section of the enhancement ( can be availed by transaction SMOD).
Pre-Requisites
The developer to work on screen exit should have essential knowledge on the following:
- DDIC concepts, including the knowledge of append structure.
- Concept of SAP Enhancements and implementing them using Projects.
- Concept of function exits.
- Knowledge on Module Pool – including subscreens, Tabstrip controls etc.
Steps