Step loops are the predecessors of table controls and are defined without individual descriptions in the Screen Painter. A step loop contains screen elements that, unlike table controls, can occupy several rows, grouped together in one group that can be repeated several times within the step loop on the screen. The attributes of the screen elements of the first group determine the attributes of the entire step loop. For this reason, the fields of a group can only be created once in each of the dynpro and the ABAP program.
Processing of step loops and table controls is based on the step loop technique, whose main features are the statements LOOP ... ENDLOOP in the dynpro flow logic. These statements cause a loop pass via the step loop rows displayed on the screen and a data transport between the ABAP program and dynpro for all like-named data objects.
In the Screen Painter, you can also determine whether the size of the step loop is fixed or variable. For each screen, you can define more than one fixed step loop, but only one variable step loop. If the user changes the vertical size of the window, this also changes the vertical size of the variable step loop, whereby the PAI event is triggered.
Independent step loops are obsolete and are replaced by table controls, which are based on step loop but encapsulate them. Accordingly, the listed variants of the LOOP statement are obsolete in the dynpro flow logic. The LOOP statement of the dynpro flow logic should only be used with the WITH CONTROL addition, which assigns a table control to the statement.