How to ensure data integrity if the user closes Access

[Adam Tippelt]

If the user clicks the red x in the top right corner, or shuts Access via task manager, is there anyway of applying some sort of procedure for any data currently open?
If you have any dirty forms when the user closes Access, it automatically saves the file, whereas I'd rather have it undo/delete current changes - I'm trying to avoid any orphan records appearing in the database should a user close the application at the incorrect time.
I know it's possible to disable the red x button and implement my own close button, however some users might not like this, and it doesn't get round the problem of closing via task manager.

Thanks.

Adam.

[NeoPa]

The correct procedure for handling a user clicking on the X in the corner or using Task Manager to kill the process is really to speak to their manager to see if they can ensure they do nothing so completely stupid in future (They needn't be fired, as long as they are locked out of rooms with computers in they should be safe. See if someone can find them some buttons to count).

Of course RL often doesn't work as smoothly as that and we all know how many otherwise intelligent beings have no idea that killing a process is any more involved than avoiding that complicated question they didn't know how to answer. Sorted. Job done :-) The time spent by IT (assuming they are themselves competent) recovering from these various problems can stretch into man days sometimes and often into man hours.

None of that is particularly helpful I'm sure. If your company were enlightened enough to apply discipline to such employees I doubt you'd be asking the question in the first place ;-)

In truth, these methods are so powerful that there is little that can be done to stop a determined idiot. However, there are events (which have related event procedures) available whereby the saving of data can be cancelled (I believe it also works in this scenario but you ought to confirm for yourself). Try using the Form_Unload() event procedure (which has a Cancel parameter built-in) and only allowing the users to close a form from a Command Button you provide for them on the form (That way you can ensure they're not hitting any Xs by putting code in the event to indicate the proper Command Button was used).

[Adam Tippelt]

HA, so true...unfortunately...

So basically the only option would be to disable the X button, thereby forcing them to close via my own quit buttons.
That was the only option I had found, but I was hoping to not do this - annoyingly most idiots start to panic when controls are missing that they expect to be there - they don't seem to understand that this is done for a reason, think that it's a fault, and believe that closing via Task Manager is a far more sensible option.

I'd like to think the employees understand enough about Access to stop them from doing something like that, but you always have to prepare for the worst. (If such common sense existed and we didn't need to handle idiots, it's likely that this tool would only have 1K lines of code instead of 10K)

Ah well. I'll have to hope that my design will prevent any damage to live data.
Probably a stupid question, but if the user closed Access via the X button or Task Manager, does the Form_Close event procedure run?

Thanks for the info on Form_Unload, I'll see if it helps.

[NeoPa]

You needn't disable the X button on the form. Simply Cancel the event unless you detect it's been triggered by your command (or even send a message to use the command). In fact, you could even treat them as synonymous, but the application close is another matter.

Adam:
if the user closed Access via the X button or Task Manager, does the Form_Close event procedure run?

I'm not in a position to test that just now, but it should be easy enough to. Shove in an event procedure and see whether or not it runs.

In a rush now. Let me know how you get on or if anything else is required. I'll have more time tomorrow.

[Adam Tippelt]

Oh, I wasn't aware I could just cancel the event. When you have time can you elaborate on how I would do something like that? Is it similar to the KeyDown events?

[NeoPa]

Some events come with the inbuilt ability to be cancelled. Form_Open() & Form_Unload() are two such events.

The following code illustrates the technique, but shouldn't be used as is because otherwise the event would never complete :

Private Sub Form_Unload(Cancel As Integer)
    Cancel = True
End Sub

Typically the code should have a condition which must be met before cancelling.

[Adam Tippelt]

Hmmm...could I use a Global boolean variable? - The variable always = false unless the user exits via the correct means, then the variable = true.

And in the unload event the condition is whether the boolean variable = false.

So the system would treat it as:

If user exits via correct means then
 
Unload event doesn't run
 
Else
 
Unload event runs.
 
End if.

Would that work, or am I completely misunderstanding how the Unload event is initiated/works?

[NeoPa]

That's pretty well what I was suggesting yes.

The Command Button that you want them to use would have some code setting the variable (Private within each Form I would suggest.) to True. Until that point it would be False by default.

[Adam Tippelt]

Ok cheers NeoPa, that seems like a pretty straight forward way to solve the problem.

Thanks.

Adam.

[NeoPa]

Happy to help Adam :-)