excel/VBA pass a sheetname to a function - excel

Question

i have few sheet, and a need for once of it that a specific cell (A1) is equal "1" the label color become green once the change their value.
I declare in a ThisWorkBook the following function:
Public Function ColorLabel(LabelName)
Set Foglio = Sheets(LabelName)
Set Target = Foglio.Range("A1")
If Target = "1" Then
Foglio.Tab.ColorIndex = 4
Else
Foglio.Tab.ColorIndex = xlNone
end if
End Function
So, in every sheet i define the following code
Private function Worksheet_Change(ByVal Target As Range)
ColorLabel(ActiveSheet.CodeName)
end function
but I get the following error
Compilation error. Expected variable or routine and not form
What's wrong?
Someone help me?
Thanks!

Answer 1

Your Public Function ColorLabel(LabelName) should be placed in a Module, not inside one of the Sheets or the Workbook. Usualy we place there code that is related only to Sheets events or Workbook events.
see image for Public Function ColorLabel(LabelName) code
Your Private function Worksheet_Change(ByVal Target As Range) should be in the Workbook_SheetChange event (in the Workbook module):
Code:
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
ColorLabel (Sh.Name)
End Sub
You could improve your code, by not calling ColorLabel function on every change made to any cell in any sheet, by checking if the Target is inside Range("A1"), see code below:
Improved Code:
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
' call the ColorLabel function only if value in Cell A1 was modified
If Not Intersect(Target, Range("A1")) Is Nothing Then
ColorLabel (Sh.Name)
End If
End Sub

Answer 2

If the function is defined in the ThisWorkbook module, you should call it this way:
ThisWorkbook.ColorLabel Me.Name
and by the way, as it is written, ColorLabel shoud be a Sub not a function (it does not return anything).
However, better design would be:
move the sub to an independent code module
or
rename the sub into an event handler using Workbook_SheetChange

Answer 3

Why do you need to pass the name of the worksheet at all? Just pass a reference to the worksheet itself:
Public Function ColorLabel(Foglio As Worksheet)
Dim Target As Range
Set Target = Foglio.Range("A1")
If Target.Value = "1" Then
Foglio.Tab.ColorIndex = 4
Else
Foglio.Tab.ColorIndex = xlNone
End If
End Function
'If this is the event handler you want...
Private Function Worksheet_Change(ByVal Target As Range)
ColorLabel Me
End Function
'Or in ThisWorkbook:
Private Sub Workbook_SheetChange(ByVal Sh As Object, ByVal Target As Range)
ColorLabel Sh
End Sub