Name Manager using VBA - Macro vs. Function Call Gives Different Response - vba

Question

I have an XLA I'm use to make calculations and I'd like to create variables in the Name Manager to use in those calculations. I want to check to see if those named ranged already exist and if not let the user assign values to them. I have a Sub() that I'm using to set the Name Manager -example below- :
Public Sub SetNames()
On Error Resume Next
IsRangeName = CheckName("test")
If IsRangeName = Empty Then
Application.ThisWorkbook.Names.Add Name:="test", RefersTo:=0
End If
End Sub
If I go into the "Macro" menu and run the SetNames routine it works and sets test = 0 in the Name Manager.
However, what I want to do is run this through a Function and allow the function to use the variables in the Name Manager if they exist, if they don't exist then those values get set to an initial value in the Name Manager through the subroutine.
When I try to run the following code the values are never set in the Name Manager:
Sub Function1()
Call SetNames()
-Do Other Things-
End Function
All of the names are declared as global variables.
The intent is to have a user install the add-in and on the first function call using the add-in the Name Manager gets set, either to initialize the names or to allow the user to set the initial value. I don't want the user to go through the Macro ribbon option and execute the subroutine to initialize the Name Manager names.
Any help on this would be appreciated.

Answer 1

This seems to work in my quick testing, but you should be sure it performs in whatever your final use case is. It's a hack around the restrictions on a UDF being able to update the workbook, so it's outside of "normal" usage.
Sub SetNameIfMissing(swb As String)
Dim r As Name, wb As Workbook
Set wb = Workbooks(swb)
On Error Resume Next
Set r = wb.Names("test")
On Error GoTo 0
If r Is Nothing Then
Debug.Print "adding name..."
wb.Names.Add "test", 99
Else
Debug.Print "already added"
End If
End Sub
Function SetIt(v)
Dim wb
wb = Application.Caller.Parent.Parent.Name
'using Evaluate gets around the UDF restriction
Application.Caller.Parent.Evaluate "SetNameIfMissing(""" & wb & """)"
SetIt = "OK" 'or whatever return value is useful...
End Function

Answer 2

Not sure what "CheckName" is in your script - you didn't provide it .. however, I got it to work via:
1) comment out On Error Resume Next - this allows you to see CheckNames failing.
2) Replaced CheckNames with a loop to loop throw the defined names, looking for ours.
3) change your "function" definition from "sub" to "function".
test it, runs fine.
Sets the "test" name if it doesn't exist. Change it manually to another value, run again, doesn't touch it.
Public Sub SetNames()
'On Error Resume Next
For i = 1 To Application.ThisWorkbook.Names.Count
If Application.ThisWorkbook.Names(i).Name = "test" Then
IsRangeName = True
Exit For
End If
Next i
If Not IsRangeName Then
Application.ThisWorkbook.Names.Add Name:="test", RefersTo:=1
End If
End Sub
Function Function1()
Call SetNames
'-Do Other Things-
End Function