Secondary lists allow you to enhance the information presented in the basic list. The
user can, for example, select a line of the basic list for which he wants to see more
detailed information. You display these details on a secondary list.Secondary lists may
either overlay the basic list completely or you can display them in an extra window on
the screen. The secondary lists can themselves be interactive again.
How to select valid lines for secondary list ?
To prevent the user from selecting invalid lines, ABAP/4 offers several possibilities. At
the end of the processing block END-OF-SELECTION, delete the contents of one or
more fields you previously stored for valid lines using the HIDE statement. At the event
AT LINE-SELECTION, check whether the work area is initial or whether the HIDE
statement stored field contents there. In the latter case, create a secondary list, since
you previously stored field contents for valid lines only. After processing the secondary
list, clear the work area again. This prevents the user from trying to create further
secondary lists from the secondary list displayed.