NullSafe Functions: Ensuring Safe Variables

Public Class Utility

    Public Const WILDCARD_ID As Integer = -1

    '****************************************************************
    ' NullSafeString
    '****************************************************************
    Public Shared Function NullSafeString(ByVal arg As Object, Optional ByVal returnIfEmpty As String = "") As String

        Dim returnValue As String

        If (arg Is DBNull.Value) OrElse (arg Is Nothing) OrElse (arg Is String.Empty) Then
            returnValue = returnIfEmpty
        Else
            Try
                returnValue = CStr(arg).Trim
            Catch
                returnValue = returnIfEmpty
            End Try

        End If

        Return returnValue

    End Function

    '****************************************************************
    ' NullSafeInteger
    '****************************************************************
    Public Shared Function NullSafeInteger(ByVal arg As Object, Optional ByVal returnIfEmpty As Integer = WILDCARD_ID) As Integer

        Dim returnValue As Integer

        If (arg Is DBNull.Value) OrElse (arg Is Nothing) OrElse (arg Is String.Empty) Then
            returnValue = returnIfEmpty
        Else
            Try
                returnValue = CInt(arg)
            Catch
                returnValue = returnIfEmpty
            End Try
        End If

        Return returnValue

    End Function

    '****************************************************************
    '   NullSafeDouble
    '****************************************************************
    Public Shared Function NullSafeDouble(ByVal arg As Object, Optional ByVal returnIfEmpty As Integer = WILDCARD_ID) As Double

        Dim returnValue As Double

        If (arg Is DBNull.Value) OrElse (arg Is Nothing) OrElse (arg Is String.Empty) Then
            returnValue = returnIfEmpty
        Else
            Try
                returnValue = CDbl(arg)
            Catch
                returnValue = returnIfEmpty
            End Try
        End If

        Return returnValue

    End Function

    '****************************************************************
    ' NullSafeBoolean
    '****************************************************************
    Public Shared Function NullSafeBoolean(ByVal arg As Object) As Boolean

        Dim returnValue As Boolean

        If (arg Is DBNull.Value) OrElse (arg Is Nothing) OrElse (arg Is String.Empty) Then
            returnValue = False
        Else
            Try
                returnValue = CBool(arg)
            Catch
                returnValue = False
            End Try
        End If

        Return returnValue

    End Function

End Class