[TYPO3-shop] Feature suggestion for Commerce

[Peter Raykov]

Hi all,

If a shop works international, the prices must be calculated with or 
without different VATs and for different currencies. This makes the 
calculated prices ugly like 213.04 and makes impossible to show prices 
in the "supermarket" style like 59.99 or 1.95. The conventional round 
function is useless, because the introduced by the rounding error is 
different for small and big prices and can't be controlled easy.

Below is a small function written by me many years ago for MS Excel, 
that rounds a price within defined tolerance (not digital places) and 
optional formats the last digits in the "99" style (of course within the 
tolerance).

IMHO a similar Commerce feature will be very useful.

Peter

'---------------------------------------------------------
Public Function RoundFlex(N As Double, Optional Tolerance As Variant, 
Optional LastDigits As Variant) As Double
     If N <> 0 Then
         Dim K As Double, er As Single, L As Double
         Dim LD As Double, Delta As Double
         If IsMissing(Tolerance) Then
             er = 0.01       'Default Tolerance is 1%
         Else
             er = CSng(Tolerance)
             If er <= 0 Or er >= 1 Then Error.Raise 6    'Interval 0-1 only
         End If
         If IsMissing(LastDigits) Then
             Delta = 0                     'No supermarket style
         Else
             LD = CLng(LastDigits)
             If LD < 1 Then Error.Raise 6
             LD = Val("." + Str$(LD))    '<1
             Delta = 1 - LD
             er = er * LD                'to be in the tolerance
         End If
         K = 10 ^ Int(Log10(2 * Abs(N) * er))
         LD = Sgn(N) * K * Delta
         RoundFlex = K * Round(N / K + LD) - LD
     Else
         RoundFlex = 0
     End If
End Function