Requiring Input

When you are developing a worksheet that will be used by other people, you may want to make sure that they fill in certain cells before they are allowed to close the workbook. There is no built-in function in Excel to do this, but you can create a macro that will make the necessary check and stop the user for proceeding. This can be a rather simple macro, tied to the BeforeClose event.

The BeforeClose even is triggered whenever a workbook is closed by whatever means. The trick is the setting of the Cancel property within the event handler. Setting Cancel to True will stop the closing of the workbook and leaving it unchanged results in the workbook closing normally.

For example, the following macro checks whether cell A1 has anything in it; if it does, then the workbook is closed. If it doesn't, then the user is informed that something is missing and the closing is canceled.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    If Cells(1, 1).Value = "" Then
        MsgBox "Please fill cell A1"
        Cancel = True
    End If
End Sub

More elaborate macros can be created, if desired. For instance, you might have several different cells that need to be checked. The following version checks a range named "Mandatory" to see if each cell in the range contains something. If any of the cells are empty, then the workbook cannot be saved or closed. (This macro is triggered not only during the BeforeClose event, but also during the BeforeSave event.) The two event handlers are put into the code for the workbook and the ForceDataEntry macro is placed in a regular macro module.

Private Sub Workbook_BeforeClose(Cancel As Boolean)
    Cancel = ForceDataEntry()
End Sub

Private Sub Workbook_BeforeSave(ByVal SaveAsUI As Boolean, _
  Cancel As Boolean)
    Cancel = ForceDataEntry()
End Sub

Sub ForceDataEntry() As Boolean
    Dim rng As Range
    Dim c As Variant
    Dim rngCount As Integer
    Dim CellCount As Integer

    Set rng = Range("Mandatory")
    rngCount = rng.Count

    CellCount = 0
    For Each c In rng
        If Len(c) > 0 Then
            CellCount = CellCount + 1
        End If
    Next c
    ForceDataEntry = False
    If CellCount <> rngCount Then
        ForceDataEntry = True
    End If
End Sub

You should note that any implementation that requires macros (like this one does) suffers from one potential problem—users can decide to not enable macros when the workbook is loaded. If they run the workbook with the macros disabled, then they will still be able to save the workbook without all the mandatory cells containing values.

ExcelTips is your source for cost-effective Microsoft Excel training. This tip (9572) applies to Microsoft Excel 97, 2000, 2002, and 2003. You can find a version of this tip for the ribbon interface of Excel (Excel 2007 and later) here: Requiring Input.