A step loop is a repeated series of field-blocks in a screen. Each block can contain one or more fields, and can extend over more than one line on the screen.

Step loops as structures in a screen do not have individual names. The screen can contain more than one step-loop, but if so, you must program the LOOP...ENDLOOPs in the flow logic accordingly. The ordering of the LOOP...ENDLOOPs must exactly parallel the order of the step loops in the screen. The ordering tells the system which loop processing to apply to which loop. Step loops in a screen are ordered primarily by screen row, and secondarily by screen column.

Transaction TZ61 (development class SDWA) implements a step loop version of the table you saw in transaction TZ60.

Static and Dynamic Step Loops

Step loops fall into two classes: static and dynamic. Static step loops have a fixed size that cannot be changed at runtime. Dynamic step loops are variable in size. If the user re-sizes the window, the system automatically increases or decreases the number of step loop blocks displayed. In any given screen, you can define any number of static step loops, but only a single dynamic one.

You specify the class for a step loop in the Screen Painter. Each loop in a screen has the attributes Looptype (fixed=static, variable=dynamic) and Loopcount. If a loop is fixed, the Loopcount tells the number of loop-blocks displayed for the loop. This number can never change.

Programming with static and dynamic step loops is essentially the same. You can use both the LOOP and LOOP AT statements for both types.

Looping in a Step Loop

When you use LOOP AT <internal-table> with a step loop, the system automatically displays the step loop with vertical scroll bars. The scroll bars, and the updated (scrolled) table display, are managed by the system.

Use the following additional parameters if desired:

* FROM <line1> and TO <line2>

* CURSOR <scroll-var>