PRB: "DO Nesting Too Deep" with ON KEY LABEL Command from 2.0

ID: Q105146

The information in this article applies to:

• Microsoft FoxPro for MS-DOS, versions 2.0, 2.5, and 2.5a
• Microsoft FoxPro for Windows, versions 2.5 and 2.5a

SYMPTOMS

An ON KEY LABEL command that works in FoxPro 2.0 generates a "DO nesting too deep" error message in FoxPro 2.5 for MS-DOS and Windows.

CAUSE

In FoxPro 2.0, you can use a recursive ON KEY LABEL command such as ON KEY LABEL SPACEBAR KEYBOARD '{SHIFT+SPACEBAR}.' However, if you use a recursive ON KEY LABEL command in FoxPro 2.5 for MS-DOS and Windows, you will receive the above-mentioned error. This is correct behavior because you are using a key that is used to call the ON KEY LABEL command.

RESOLUTION

To correct this problem, append the PLAIN clause to the end of the ON KEY LABEL command, as shown at the end of the "More Information" section below.

MORE INFORMATION

The following code illustrates the problem. This code can be run from a .PRG file.

   * Beginning of code

   ON KEY LABEL SPACEBAR KEYBOARD '{SHIFT+SPACEBAR}'
   CLEAR
   DEFINE POPUP fruits FROM 5,5 MULTISELECT MARGIN
   DEFINE BAR 1 OF fruits PROMPT '\<Apples' MARK CHR(3)
   DEFINE BAR 2 OF fruits PROMPT '\<Bananas' MARK CHR(4)
   DEFINE BAR 3 OF fruits PROMPT '\<Grapes' MARK CHR(5)
   DEFINE BAR 4 OF fruits PROMPT '\<Lemons' MARK CHR(6)

   ACTIVATE POPUP fruits

   * End of code

   ON KEY LABEL SPACEBAR KEYBOARD '{SHIFT+SPACEBAR}' PLAIN