'**********************************************************************************************************
' Name:                 isSheetValid
' Author:               mielk | 2012-11-16
'
' Comment:              Function to check if the given Excel worksheet is valid and you can refer to its
'                       properties and methods without errors.
'
'                       Using this function is very helpful since it lets you avoid
'                       Run-time error '-2147221080 (800401a8)': Automation error.
'                       This error is generated, when the code tries to refer to a property or a method
'                       of a Sheet type variable, but the sheet pointed by this variable had been deleted
'                       before or the Excel workbook containing this sheet had been closed.
'
' Parameters:
'   wks                 The Excel worksheet to be checked.
'
' Returns:
'   Boolean             True - if the given worksheet is valid and you can refer to it without any errors.
'                       False - if the given worksheet is invalid, that means it is corrupted or had been
'                               closed or deleted before this method has been called and referring to it
'                               will raise an error.
'
'
' --- Changes log -----------------------------------------------------------------------------------------
' 2012-11-16            mielk           Function created.
'**********************************************************************************************************
Public Function isSheetValid(wks As Excel.Worksheet) As Boolean
    Const METHOD_NAME As String = "isSheetValid"
    '------------------------------------------------------------------------------------------------------
    Dim strSheetName As String
    '------------------------------------------------------------------------------------------------------
    
    On Error Resume Next
    strSheetName = wks.name
    
    'Check method is very easy - if the name of the given worksheet has been assigned to the variable
    '[strSheetName], this worksheet is valid and you can refer to it. Otherwise, error would be generated
    'and step [strSheetName = wks.name] would be skipped because of [On Error Resume Next] statement above.
    isSheetValid = VBA.Len(strSheetName)
    
End Function