ErrorMessage, Message
Unlike Error, ErrorMessage
shouldn't be part of anyone's error-handling strategy in new
applications. Like Message, it's a backward-compatibility method
included to make it possible to port FoxPro 2.x code to Visual
FoxPro.ErrorMessage fires when an object's Valid returns .F. If
you return a string, it gets displayed in a WAIT WINDOW. Message
is similar. It fires when you land on an object, and places the
returned string in the Windows-style status bar (or at the bottom
of the screen, if you're not using the status bar).
Usage
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PROCEDURE oObject.ErrorMessage | oObject.Message
[ LPARAMETERS nIndex ]
|
ErrorMessage and Message share a weird bug with When and
Valid. When you define an ErrorMessage method or a Message method
for a control array, it doesn't always fire when it should. For
some types of controls, the class the control is based on must
include a definition for the same method or FoxPro can't find the
one for the control array. You don't have to actually put
anything in the method, just define it. Very strange. Of course,
it's also fairly irrelevant because we can't think of any reason
to use control arrays.ErrorMessage is the Visual FoxPro
replacement for the ERROR clause of @ ... GET. You can actually
put anything you want in the method, but whatever you return is
displayed in a WAIT WINDOW (if NOTIFY is ON). A better choice is
to present whatever message you need in the control's Valid
(using WAIT WINDOW or MessageBox) and then return 0 from the
Valid.Message replaces the MESSAGE clause of @ ... GET. It works
the same as ErrorMessage except the returned text appears in the
status bar. StatusBarText does the same thing and isn't labeled
"For Backward Compatibility."
Example
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PROCEDURE spnMonth.ErrorMessage
RETURN "Choose a month between 1 and 12"
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Copyright © 2002-2018 by Tamar E. Granor,
Ted Roche, Doug Hennig, and Della Martin. Click for license
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