Pass array function into user defined function - vba

Question

I have a standard user defined function that concationates all the unique values. What I am trying to do is to perform this function on a range that satisfies a condition.
Function ConcatUniq(xRg As Range, xChar As String) As String
'updateby Extendoffice 20151228
Dim xCell As Range
Dim xDic As Object
Set xDic = CreateObject("Scripting.Dictionary")
For Each xCell In xRg
xDic(xCell.Value) = Empty
Next
ConcatUniq = Join$(xDic.Keys, xChar)
Set xDic = Nothing
End Function
Lets make an example:
If we have the following data:
A1:A5 = {1,2,2,4,1}
B1:B5 = {"group1", "group1","group1", "group2", "group2"}
C1 = "group1"
Now I want to find the unique values using the ConcatUniq function for all numbers that are in group1. Usually, if I want to perform another function for example the median I would do the following:
=MEDIAN(IF(B1:B5=C1,A1:A5))
Activate it using cntrl shift enter which gives 2 (create an array function from it).
For some reasons this does not work in combination with a user defined function.
=ConcatUniq(IF(B1:B5=C1,A1:A5)," ")
Desired result:
1 2
Does someone know how I could fix this problem?

Answer 1

You need to use ParamArray to accommodate array returned from Excel's array formula. As ParamArray should always be the last one, so your method signature will change.
This will work with =ConcatUniq(" ",IF(B1:B5=C1,A1:A5)) on CTRL + SHIFT + ENTER
Public Function ConcatUniq(xChar As String, ParamArray args())
Dim xDic As Object
Dim xVal
Set xDic = CreateObject("Scripting.Dictionary")
For Each xVal In args(0)
If Not Not xVal Then
xDic(xVal) = Empty
End If
Next
ConcatUniq = Join$(xDic.Keys, xChar)
End Function

Answer 2

Perhaps something like this:
Public Function ConcatUniq(ByVal rangeOrArray As Variant, ByVal xChar As String) As String
Dim generalArray As Variant
If IsArray(rangeOrArray) Then
'operate on it as if was an array
generalArray = rangeOrArray
Else
If TypeName(rangeOrArray) = "Range" Then
'operate on it as if was a Range
If rangeOrArray.Cells.Count > 1 Then
generalArray = rangeOrArray.Value
Else
generalArray = Array(rangeOrArray.Value)
End If
Else
'Try to process as if it was a derivative of a value of a single cell range.....
generalArray = Array(rangeOrArray)
End If
End If
Dim xDic As Object
Set xDic = CreateObject("Scripting.Dictionary")
Dim xCell As Variant
For Each xCell In generalArray
If xCell <> False Then xDic(xCell) = Empty ' EDIT - HACKY....
Next
ConcatUniq = Join$(xDic.Keys, xChar)
End Function
You can see that that whole block of if-elses can be factored out to be a separate function to transform worksheet input to a unified form for operating on values of a worksheet.

Answer 3

The easiest solution would probably be to introduce an additional function. This function would take care of the condition and would generate an array consisting only of data fulfilling the condition.
Try something like this:
function condition_check(data1() as integer, data2() as string, condition_value as string) as integer
number_of_elements = Ubound(data1)
j = 0
for i = 0 to number_of_elements
if data2(i) = condition_value then
condition_check(j) = data1(i)
j = j+1
end if
next i
end function