Preventing close buttons from saving records in MS Access

Question

In a Microsoft Access form, whenever the current record changes, any changes in bound controls are silently saved to the database tables. This is fine, but I don't want it to happen when a user closes a form, because it is the direct opposite of what many people would expect.

The best example is when you try to close an excel file with unsaved changes, it asks whether the changes should be discarded. This is exactly what I'm trying to achieve in Access, but can't find any way to trap the close button's event in VBA.

The form's Unload event is the first event that is triggered when someone clicks the close button, but by then the changes are already written to the database.

Is this at all possible, or do I have to create my own close buttons? I'm comfortable with writing large amounts of code for trivial things like this but I hate having to clutter the GUI.

Answer 1

You have to work with Form_BeforeUpdate event. Below is an example; however it does create a typical warning message: "You can't save this record at this time. Microsoft Access may have encountered an error while trying to save a record. ..." - depending on your database settings. You can use simple workaround below to avoid displaying of that message.

Private Sub Form_BeforeUpdate(Cancel As Integer)
   Cancel = True
   'Or even better you can check certain fields here (If Then...)

End Sub


Private Sub Form_Error(DataErr As Integer, Response As Integer)
    If DataErr = 2169 Then 
        Response = True
    End If
End Sub

Answer 2

Sean gave an almost correct answer but it leaves gaps.

In general, the FORM's BeforeUpdate is the most important form event. It is your LAST line of defense and ALWAYS runs prior to a record being saved regardless of what prompted the save (form close, new record, your own save button, clicking into a subform, etc.) Although I occasionally use the control's BeforeUpdate event just so the user gets the error message sooner, the bulk of the validation code I write runs in the Form_BeforeUpdate event. This is the event you MUST use if you want to ensure that certain controls are not empty. No control level event will do this reliably for all situations. Primarily because if the control never gets focus, no control level event ever fires. Form_BeforeUpdate is also the event you would use if your validation involves multiple fields. If you are using any other control or event level event, you are wasting your time. There is always away around your "trap" and your table almost certainly contains invalid data.

Regarding the OP's question. If you want to force people to use your own save button and prompt them if they don't then you need a form level variable as Sean's suggestion implied. The only difference, is that you need to set it to False, in the form's Current event NOT the Open event. You want the flag to be reset for EVERY new record, not just when the form opens. Then you set it to True in your save button click event, just before you force the record to save with DoCmd.RunCommand acCmdSaveRecord.

Then finally, in the Form_BeforeUpdate event, you check the value of the variable.

If bClose = False Then
   If MsgBox("Do you want to save the changes?", vbYesNo) = vbNo Then
       Cancel = True
       If MsgBox("Do you want to discard the Changes?", vbYesNo) = vbYes Then           
            Me.Undo
       End If
       Exit Sub
   End If
End If

Answer 3

this is code I have that checks to see if the form is being closed or saved.

Private Sub Form_BeforeUpdate(Cancel As Integer)

If Not UsingSaveButton Then
    If MsgBox("Abandon Data?", vbInformation + vbYesNo) = vbNo Then
        Cancel = True
    Else
        DoCmd.RunCommand acCmdUndo
    End If
End If
End Sub

I have a Boolean Flag that is set to False on loading, and then when my Save button is used, I set it to true to allow the update to run through.
If the flag is not set, then they are leaving the record (either through going to a different record, or closing the form) so I ask if they actually want to save the changes.
The Cancel = True aborts the exit of the form or the move to a different record if any changes have been made.
The DoCmd.RunCommand acCmdUndo undoes any changes so they are not saved.