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Q136071: DOC: ON ERROR Not Invoked when Error Occurs in Error Event

Article: Q136071
Product(s): Microsoft FoxPro
Version(s): WINDOWS:3.0,3.0b,5.0,5.0a
Operating System(s): 
Keyword(s): kbdocerr kbvfp300bBUG kbvfp500aBUG kbvfp500bug
Last Modified: 15-FEB-2000

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The information in this article applies to:

- Microsoft Visual FoxPro for Windows, versions 3.0, 3.0b, 5.0, 5.0a 
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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"

Additional query words:

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Keywords          : kbdocerr kbvfp300bBUG kbvfp500aBUG kbvfp500bug 
Technology        : kbVFPsearch kbAudDeveloper kbVFP300 kbVFP300b kbVFP500 kbVFP500a
Version           : WINDOWS:3.0,3.0b,5.0,5.0a

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