Hi Chuck,
GotFocus/LostFocus is what all the other dumbass Windows Programming
languages have. But we have more power, more control since we have WHEN =
and
VALID. Those additional events make the difference between General =
Purpose
languages and highly specialized langguages, tailored for their job: =
Perfect
data-management. And perfect data starts with clean data, with validated
data.
Maybe it's clearer this way:
In GotFocus, you just entered the Control, in Lostfocus, you are already =
out
of the control. WHEN takes precedence before you enter, VALID is fired
BEFORE you are ALLOWED to leave.
Another difference between VALID and LOSTFOCUS is very important: As =
soon as
you leave the VALID, the entered data is accepted as to be validated and =
ok,
thus the Fieldstate is set (see GETFLDSTATE() for more info) which in =
turn
means, that the entered data gets written to the table. You can't revert
that in Lostfocus!
Another analogy would be, that you compare your object with a =
supermarket.
The VALID is the Cashregister-Zone. You need to validate each customer =
for
theft; that's what those antennas are good for. If you would do the
validation after the theft left the store (LOSTFOCUS), you're out of =
luck,
the user is already out of the objects responsibility.
Servus
wOOdy
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