DOC: ON ERROR Not Invoked when Error Occurs in Error Event (136071)



The information in this article applies to:

  • Microsoft Visual FoxPro for Windows 3.0
  • Microsoft Visual FoxPro for Windows 3.0b
  • Microsoft Visual FoxPro for Windows 5.0
  • Microsoft Visual FoxPro for Windows 5.0a

This article was previously published under Q136071

SUMMARY

When an error occurs while executing an object's Error event procedure, Visual FoxPro suspends execution and displays the error message. Even an ON ERROR routine currently in effect is ignored. The Visual FoxPro Help file gives the following information about the Error event:

If a second error occurs in the Error event procedure while it is handling an error, Visual FoxPro calls the ON ERROR routine.

This is incorrect. When an error occurs while executing an object's Error event procedure, Visual FoxPro suspends execution and displays the error message. Even an ON ERROR routine currently in effect is ignored.

MORE INFORMATION

If code placed in an Error event handler can itself generate an error, place all error-handling code within the ON ERROR routine.

An object's Error event procedure is triggered when there is a run-time error in a method of that object. Using the Error event allows you to define code to handle an error at the object level.

Code to Reproduce Behavior

   SET PROCEDURE TO SYS(16)
   ON ERROR DO procerror

   oform1=CREATE('myform')
   oform1.SHOW
   read events

   DEFINE CLASS myform AS FORM
     ADD OBJECT cmd1 AS CommandError
   ENDDEFINE

   DEFINE CLASS CommandError AS COMMANDBUTTON
      TOP=5
      LEFT=10
      WIDTH=50
      PROCEDURE CLICK
         wiat WINDOW     && Error in code. Calls the error event
      ENDPROC

     PROCEDURE ERROR
      PARAMETERS x,Y,z,T
         WAIT WINDOW u    && Another error. Should call the ON ERROR
      ENDPROC
   ENDDEFINE

   PROCEDURE procerror
     WAIT WINDOW "this is an error"
				

Modification Type:MajorLast Reviewed:5/7/2003
Keywords:kbBug kbdocerr KB136071