Sap Technical

Screen Attributes

From the user's point of view, a transaction is a sequence of screens, displayed one after another. How do I determine this sequence? The transactions's attributes determine the first screen to be displayed. The attributes of the individual screens determine which screen is displayed after the current screen. You can also set the number of the subsequent screen dynamically from within the ABAP program.

For our example, the screen attributes need not be changed, since no subsequent screen is called.

Layout

To start the layout editor in the Screen Painter, choose Fullscreen. Here you can determine the layout of the screen. For Transaction DEMO_TRANSACTION, the desired fields can be copied from table SPFLI of the ABAP Dictionary. For further information, refer to the Structure link Screen Painter documentation.

Field Attributes

In the element list, you can display or change the attributes of each field on the screen. (Input/output fields, required fields, whether the possible entries button is displayed, whether the field is invisible, and so on.)

The fields Airline (SPFLI-CARRID) and Flight number (SPFLI-CONNID) are defined as input/output fields. All other fields are used only for outputting the flight data.

Flow logic

The flow logic code of a dialog screen consists of a few statements that syntactically resemble ABAP statements. You cannot use flow logic keywords in ABAP programs, or ABAP statements in screen flow logic. You enter the flow control code in the Screen Painter as one component of the screen.

The flow control for the screen in Transaction DEMO_TRANSACTION looks like this:

PROCESS BEFORE OUTPUT.

MODULE set_status_0100.

*

PROCESS AFTER INPUT

MODULE user_command_0100.

The PROCESS statement introduces the flow logic for the two events PBO and PAI. The MODULE statements each call one dialog module in the associated ABAP program. In this example, there is only one MODULE for each event PBO and PAI. However, the flow logic can, of course, contain more statements, calling more than one dialog module in each event. You can also call the same dialog module from more than one screen.

The flow logic syntax contains only a few statements. The most important are MODULE, FIELD, CHAIN, LOOP, and CALL SUBSCREEN. For information about flow logic syntax, choose Utilities Help on... from the flow logic editor. A dialog box appears, in which you select Flow logic keyword