Question

I simply want to fill-up cells in my spreadsheet from a VBA function. By example, I would like to type =FillHere() in a cell, and in result I will have a few cells filled-up with some data.

I tried with such a function:

Function FillHere()
  Dim rngCaller As Range
  Set rngCaller = Application.Caller
  rngCaller.Cells(1, 1) = "HELLO"
  rngCaller.Cells(1, 2) = "WORLD"
End Function

It breaks as soon as I try to modify the range. Then I tried this (even it’s not really the behavior I’m looking for):

Function FillHere()
    Dim rngCaller As Range
    Cells(1, 1) = "HELLO"
    Cells(1, 2) = "WORLD"
End Function

This is not working neither. But it works if I start this function from VBA using F5! It seems it’s not possible to modify anything on the spreadsheet while calling a function… some libraries do that though…

I also tried (in fact it was my first idea) to return a array from the function. The problem is that I only get the first element in the array (there is a trick that implies to select a whole area with the formula at the top left corner + F2 + CTRL-SHIFT-ENTER, but that means the user needs to know by advance the size of the array).

I’m really stuck with this problem. I’m not the final end-user so I need something very easy to use, with, preferably, no argument at all.

PS: I’m sorry I asked this question already, but I wasn’t registered at that time and it seems that I can’t participate to the other thread anymore.

Answer 1

You will need to do this in two steps:

Change your module to be something like:

Dim lastCall As Variant
Dim lastOutput() As Variant

Function FillHere()
    Dim outputArray() As Variant
    ReDim outputArray(1 To 1, 1 To 2)
    outputArray(1, 1) = "HELLO"
    outputArray(1, 2) = "WORLD"

    lastOutput = outputArray
    Set lastCall = Application.Caller

    FillHere = outputArray(1, 1)
End Function

Public Sub WriteBack()
    If IsEmpty(lastCall) Then Exit Sub
    If lastCall Is Nothing Then Exit Sub

    For i = 1 To UBound(lastOutput, 1)
        For j = 1 To UBound(lastOutput, 2)
            If (i <> 1 Or j <> 1) Then
                lastCall.Cells(i, j).Value = lastOutput(i, j)
            End If
        Next
    Next

    Set lastCall = Nothing
End Sub

Then in order to call the Sub go into the ThisWorkbook area in VBA and add something like:

Private Sub Workbook_SheetCalculate(ByVal Sh As Object)
    Call WriteBack
End Sub

What this does is return the value of the topleft cell and then after calculation completes populates the rest. The way I wrote this it assumes only one FillHere function will be called at a time. If you want to have multiple ones which recalculate at the same time then you will need a more complicated set of global variables.

One word of warning is that this will not care what it overwrites when it populates the other cells.

Edit:
If you want to do this on a Application wide basis in an XLA. The code for the ThisWorkbook area should be something like:

Private WithEvents App As Application

Private Sub App_SheetCalculate(ByVal Sh As Object)
    Call WriteBack
End Sub

Private Sub Workbook_Open()
    Set App = Application
End Sub

This will wire up the Application Level calculation.