Attribute VB_Name = "udf_isNothing"
'-------------------------------------------------------------------------------
'File         : udf_isNothing.bas
'               Copyright mpl by ERB software
'               All rights reserved
'               http://wiki.yaslaw.info/dokuwiki/doku.php/vba/cast/strtodate
'Environment  : VBA 2007 +
'Version      : 1.0.3
'Name         : _isNothing
'Author       : Stefan Erb (ERS)
'History      : 30.04.2014 - ERS - Creation
'               11.07.2018 - ERS - Leerer Array mit IsMissing prüfen
'               03.09.2018 - ERS - Korrektur bei isMissing
'-------------------------------------------------------------------------------
Option Explicit

'/**
' * Prüft, ob eine Variable Null, Empty, Nothing, Leerstring, leerer Array etc ist
' *
' *     boolean = isNothing(object)
' *     boolean = isNothing(vaule)
' *
' * @param  Variant     Variable die geprüft werden soll
' * @return Boolean
' */
Public Function isNothing(ByRef iValue As Variant) As Boolean
    isNothing = True
    Select Case TypeName(iValue)
        Case "Nothing", "Empty", "Null":    Exit Function
        Case "Collection", "Dictionary":    If iValue.count = 0 Then Exit Function
        Case "String":                      If Len(trim(iValue)) = 0 Then Exit Function
        Case "Iterator":                    If Not iValue.isInitialized Then Exit Function
        '//TODO: weitere Spezialfälle
        Case Else:
            If IsArray(iValue) Or IsMissing(iValue) Then Exit Function
    End Select
    isNothing = False
End Function