Prevent field value change

[David Boomer]

I am trying to prevent changes to a field that has been previously entered:

I placed this code in the CanEditField field rule

tbl = table.current()
if tbl.mode_get() = 1 Then
ui_msg_box("Mode: Change Customer# YOU CANNOT CHANGE CUSTOMER# ONCE ASSIGNED TO AN ORDER!!", "You CANNOT change the Customer once assigned to an Order!!",UI_STOP_SYMBOL+UI_OK)
tbl.change_end(.f.)
Cancel(.f.)

Changes can still be made to the field.

How can I get this to work?

[Stan Mathews]

Re: Prevent field value change

Put the cancel() before the message and finish your if loop

tbl = table.current()
if tbl.mode_get() = 1 Then
	Cancel(.f.)
	ui_msg_box("Mode: Change Customer# YOU CANNOT CHANGE CUSTOMER# ONCE ASSIGNED TO AN ORDER!!", "You CANNOT change the Customer once assigned to an Order!!",UI_STOP_SYMBOL+UI_OK)
	tbl.change_end(.f.)
end if

[Stan Mathews]

Re: Prevent field value change

Might be a little cleaner to just set the Date Entry, Skip expression to something like

if(alltrim(yourfieldname)>"",.T.,.F.)

[Tom Cone Jr]

Re: Prevent field value change

I'm not sure it matters but strictly speaking your script, once it's patched, will prevent the user from being able to set focus in this field ONLY when the table is in change mode. I'd be concerned about two situations:

a) what if there are no changes pending and the user clicks on the field with her mouse ? Will this script prevent edits ? i.e. what if the mode of the table becomes "CHANGE" after the user clicks into the field?

b) what if the record was saved without a customer in the first place ? How do they "fix it" ?

I'd be inclined to block edits if the field is not empty.

[David Boomer]

Re: Prevent field value change

Thanks Stan & Tom...

if(alltrim(yourfieldname)>"",.T.,.F.) is a great idea... I will use it in other cases but in this case I have modified my requirements and have decided to allow a change after a warning...
So... Here is the code that I am now using to prevent a change:

if Orders->Custnum = 0 then
end
end if

response = ui_msg_box("??? CHANGE CUSTOMER NUMBER ???","Change Customer Number? Are you sure... If Payments have been made the database will have errors!??",UI_QUESTION_SYMBOL+UI_ATTENTION_SYMBOL+UI_OK_CANCEL)

if response <> 1 then
ui_msg_box("!!! Date To Process Change Aborted !!!","Change Customer Number Aborted by User",UI_INFORMATION_SYMBOL+UI_OK)
Cancel()
end
end if

ui_msg_box("!!! Change DateToProcess has been allowed!... ","If Payments have been made, the database will contain errors that will cost $$$ !!!!",UI_ATTENTION_SYMBOL+UI_OK)

So far it is working well.