UnNest indefinite number of nested objects in vba - vba

Question

I would like to take any number of objects via a ParamArray and then add them, or variables nested within them to a collection. The tricky part is that if that nested object is a container of some sort (collection, scripting dictionary or even a custom class with a count method) also has variables nested within it, I want it to return those in the collection, NOT the container.
It would go something like this, let's start by creating a use case:
Sub MakeItems()
Dim ReturnedColl as Collection
Dim aString as String
Dim TopColl as New Collection, NestedColl as New Collection, SubNestedDic as New Dictionary
Dim aRangeofManyCells as Range, aRangeofOneCell as Range
Dim anObject as newObject, NestedObject as New Object, SubNestedObject as New Object
aString = "Just a string"
Set aRangeofManyCells = Range("A1:C3")
Set aRangeofOneCell = Range("A4")
SubNestedDic.Add SubNestedObject
SubNestedDic.Add aRangeofOneCell
NestedColl.Add SubNestedDic
NestedColl.Add NestedObject
NestedColl.Add SubNestedDic
NestedColl.Add aRangeofManyCells
TopColl.Add aString
TopColl.AddNestedColl
Set ReturnedColl = UnNest(TopColl, TopColl, anObject, Range("Sheet1:Sheet3!Q1"))
For each Item in ReturnedColl
'do something
Next Item
End Sub
Here comes the part I can't figure out.
I would want to do a loop like this making the Item the new Items, and then look into each Item within item (if it has any), but without losing track of the original Items, because I'll have to go to the next Item.
Function UnNest(ParamArray Items() as Variant) as Collection
For Each Item in Items
If Item 'is a container of some sort' Then
'some kind of loop through all nests, subnests, subsubnests,...
Else
UnNest.Add Item
Endif
Next Item
End Function
So the end result should be a collection that holds:
"Just a String" from aString
9 range objects corresponding to the cells Range("A1:C3") from aRangeofManyCells
1 range object corresponding to Range("A4"), from aRangeofOneCell
The objects anObject, NestedObject, and SubNestedObject
All of the above 2x, because I put TopColl as an argument to the Function 2x
And also,
an additional anObject, because I added that as an argument to the function
3 Range objects, corresponding to Sheet1Q1, Sheet2Q2, Sheet3Q3
I know that's a tall order, but there has got to be some way to do that loop.
Thanks for any help!

Answer 1

This routine would appear to solve one of your use cases. Certainly it worked for me although I was not passing anything other than regular variables and arrays.
One problem I could not overcome was that I could not determine the type of an Object. Unless you can solve that problem, I do not see how to achieve your entire objective.
Sub DeNestParamArray(RetnValue() As Variant, ParamArray Nested() As Variant)
' Coded Nov 2010
' Each time a ParamArray is passed to a sub-routine, it is nested in a one
' element Variant array. This routine finds the bottom level of the nesting and
' sets RetnValue to the values in the original parameter array so that other routine
' need not be concerned with this complication.
Dim NestedCrnt As Variant
Dim Inx As Integer
NestedCrnt = Nested
' Find bottom level of nesting
Do While True
If VarType(NestedCrnt) < vbArray Then
' Have found a non-array element so must have reached the bottom level
Debug.Assert False ' Should have exited loop at previous level
Exit Do
End If
If NumDim(NestedCrnt) = 1 Then
If LBound(NestedCrnt) = UBound(NestedCrnt) Then
' This is a one element array
If VarType(NestedCrnt(LBound(NestedCrnt))) < vbArray Then
' But it does not contain an array so the user only specified
' one value; a literal or a non-array variable
' This is a valid exit from this loop
Exit Do
End If
NestedCrnt = NestedCrnt(LBound(NestedCrnt))
Else
' This is a one-dimensional, non-nested array
' This is the usual exit from this loop
Exit Do
End If
Else
Debug.Assert False ' This is an array but not a one-dimensional array
Exit Do
End If
Loop
' Have found bottom level array. Save contents in Return array.
ReDim RetnValue(LBound(NestedCrnt) To UBound(NestedCrnt))
For Inx = LBound(NestedCrnt) To UBound(NestedCrnt)
If VarType(NestedCrnt(Inx)) = vbObject Then
Set RetnValue(Inx) = NestedCrnt(Inx)
Else
RetnValue(Inx) = NestedCrnt(Inx)
End If
Next
End Sub
Public Function NumDim(ParamArray TestArray() As Variant) As Integer
' Returns the number of dimensions of TestArray.
' If there is an official way of determining the number of dimensions, I cannot find it.
' This routine tests for dimension 1, 2, 3 and so on until it get a failure.
' By trapping that failure it can determine the last test that did not fail.
' Coded June 2010. Documentation added July 2010.
' * TestArray() is a ParamArray because it allows the passing of arrays of any type.
' * The array to be tested in not TestArray but TestArray(LBound(TestArray)).
' * The routine does not validate that TestArray(LBound(TestArray)) is an array. If
' it is not an array, the routine return 0.
' * The routine does not check for more than one parameter. If the call was
' NumDim(MyArray1, MyArray2), it would ignore MyArray2.
Dim TestDim As Integer
Dim TestResult As Integer
On Error GoTo Finish
TestDim = 1
Do While True
TestResult = LBound(TestArray(LBound(TestArray)), TestDim)
TestDim = TestDim + 1
Loop
Finish:
NumDim = TestDim - 1
End Function