Kbase P20050: Error 4123 multiple WAIT-FOR's not correctly nested
| Autor |
Progress Software Corporation - Progress |
| Acesso |
Público |
| Publicação |
18/03/2009 |
|
Status: Verified
SYMPTOM(s):
None of the widgets used in WAIT-FOR statement are SENSITIVE WAIT-FOR terminated. (4123)
FACT(s) (Environment):
All Supported Operating Systems
Progress 9.x
OpenEdge 10.x
CHANGE:
Closed windows in different order
CAUSE:
Well known programing problem at the application level. It happens when multiple WAIT-FOR statements are used and when they are not correctly nested: the event waited by a first WAIT-FOR is fired before the event of another WAIT-FOR that came later. As a consequence, the flow of the program is lost.
FIX:
Take care to ensure that the WAIT-FOR statements are correctly nested (i.e. make the event of a first WAIT-FOR impossible to occur before the event of a WAIT-FOR that comes next, as show below)
ParentWinHandle:VISIBLE = NO. /* so it is impossible to close the */
/* window and WAIT-FOR CLOSE OF */
/* THIS-PROCEDURE remains active */
RUN ChildWindow.w. /* want the WAIT-FOR in this Child */
/* Window to be active which makes */
/* two active WAIT-FOR statements */
ParentWindowHandle:VISIBLE = YES.
However, keep in mind that the best way to design event driven applications in Progress is to use a single WAIT-FOR statement for the entire application.