SAP comprises of the following events.
1. Initialization :
This is done before the standard selection screen is being processed.
Purpose : To set values to the selection text fields and to pass values to the parameters that are defined.
2. At selection screen :
The various validation processes take place at this level.
The checking of the text box, radio button values takes place at this event type.
The processing can be done as per the following methods .
a. single text box processing.
b. multiple text box processing.
c.radio button processing.
d. block processing.
e. field help processing.
Purpose ; To impose several constraints and limit the various possible inputs to the selection screen.
3. Start of selection :
It comprises of the non-declarative statements. It takes place before the first processing statement from the tables.
Purpose : It helps in preparing an outline for the data in case of lists.
4. Get :
The get function involves in getting the values from the table and then displaying them in the output screen.
5. Get late :
This is used to get the values from the tables after the initial processing of the values during the execution of the program.
6. End of selection:
This is to display the final output of the program from the tables.