Trouble referencing sheet code names - excel

Question

Here's the basic problem: I am writing an Excel macro and I would like to use the worksheet code names to try to eliminate any errors down the road. I can use the code name for Sheet1 and it works fine, but when I try to use the other codes, like Sheet3 or Sheet7 the editor doesn't recognize them and if I run the macro Excel kicks up an error telling me that my "variable is not defined".
For example:
Option Explicit
Sub Test()
Dim SheetObject As Worksheet
Dim SheetObject2 As Worksheet
Set SheetObject = Sheet1
Set SheetObject2 = Sheet3
MsgBox (SheetObject.Name)
MsgBox (SheetObject2.Name)
End Sub
If I comment out any code referring to SheetObject2 the macro runs correctly. If I put them in I get the errors. I definitely have a Sheet3, and the code name is definitely Sheet3. I've looked around Google all day and can't seem to come up with any solutions, any help would be great.
Thanks in advance,
Jesse

Answer 1

My last employer collected data and created national statistics. Much of that data came in the form of Excel workbooks so I have had a lot of relevant experience.
If you are running your own macro and if this is a one-off exercise then tests like this may be adequate:
Debug.Assert WbookTgt.WsheetTgt.Range("A1").Value = "Date"
Many languages have an Assert statement as a development aid; this is the VBA version. If the assertion is not true, the macro will stop with this statement highlighted.
If this approach is not adequate, you should consider developing parameterised macros that perform checking and updating tasks. I have looked through some of my old macros but most would not be intelligible to someone new to VBA. I have extracted code to create two macros which I hope will give you some ideas.
Macro 1 - OpenWorkbook
Organisations that regularly supply data often use names like: "Xxxxx 1409.xlsx" and "Xxxxx 1410.xlsx" for the September and October versions of their data. You could, for example, update the macro each month for the latest name or you could change the filename to a standard value. Either of these possibilities would be a nuisance and I would be particularly opposed to the second idea because I like to archive all the workbooks I have processed.
OpenWorkbook() uses the Dir statement to search a folder for a file that matches a template such as “Xxxxx*.xls*”. If a single file matches this template, the macro opens the workbook and returns a reference to it.
Macro 2 – CheckWorksheets
You may have noticed that some VBA routines have a fixed number of parameters while others have a variable number of parameters. For example, the following are all valid calls of CheckWorksheets:
If CheckWorksheets(WbookTgt, WbookThis, “Name1”) then
If CheckWorksheets(WbookTgt, WbookThis, “Name1”, “Name2”) then
If CheckWorksheets(WbookTgt, WbookThis, “Name1”, “Name2”, “Name3”) then
CheckWorksheets has three parameters. The first two are workbook references. The third is ParamArray SheetName() As Variant. Any parameter after the first two is placed in array SheetName which can be as large as necessary. Here all the trailing parameters are strings but they could be of any type.
I can use OpenWorkbook to open this month’s version of the source file and then use CheckWorksheets to confirm all the worksheets required by my macro are present.
Worksheet Errors”
These two macros require a worksheet Errors be present in a specified workbook. If the macros detect an error, they add a detailed error message to this worksheet. I have found this a convenient technique for capturing the details of any errors.
Macros Demo1 and Demo2
I have included two macros that demonstrate the use of these macros with workbooks on my system. If you amend Demo1 and Demo2 to operate on some of your workbooks, you should get an idea of what OpenWorkbook and CheckWorksheets can do for you.
Come back with questions as necessary but the more you can decipher OpenWorkbook and CheckWorksheets yourself, the faster you will develop your own skills
Option Explicit
Sub Demo1()
Dim Path As String
Dim WbookThis As Workbook
Dim WbookTgt As Workbook
' Application.ThisWorkbook identifies the workbook containing this macro.
Set WbookThis = Application.ThisWorkbook
' I find it convenient to place my target workbooks in the folder
' holding the workbook containing the macro(s).
Path = WbookThis.Path
Set WbookTgt = OpenWorkbook(Path, "Combined*.xls*", WbookThis)
If WbookTgt Is Nothing Then
' Detailed error message already recorded in "Errors"
Call MsgBox("Wokbook failed checks", vbOKOnly)
Else
With WbookTgt
Debug.Print .Path & "\" & .Name & " opened."
.Close SaveChanges:=False
End With
End If
End Sub
Sub Demo2()
Dim Path As String
Dim WbookThis As Workbook
Dim WbookTgt As Workbook
' Application.ThisWorkbook identifies the workbook containing this macro.
Set WbookThis = Application.ThisWorkbook
' I find it convenient to place my target workbooks in the folder
' holding the workbook containing the macro(s).
Path = WbookThis.Path
Set WbookTgt = OpenWorkbook(Path, "Combined 2.04.xls*", WbookThis)
If WbookTgt Is Nothing Then
' Detailed error message already recorded in "Errors"
Call MsgBox("Wokbook failed checks", vbOKOnly)
Exit Sub
End If
With WbookTgt
If Not CheckWorksheets(WbookTgt, WbookThis, "Critical Path", "Dyn Dims") Then
Call MsgBox("Wokbook failed checks", vbOKOnly)
.Close SaveChanges:=False
Exit Sub
End If
Debug.Print .Path & "\" & .Name & " contains worksheets Critical and Dym Dims"
.Close SaveChanges:=False
End With
End Sub
Function CheckWorksheets(ByRef WbookTgt As Workbook, ByRef WbookError As Workbook, _
ParamArray SheetName() As Variant) As Boolean
' * Return True if WbookTgt contains every specified worksheet.
' * WbookTgt is the workbook to be checked
' * WbookError identifies the workbook containing worksheet "Error" to which any
' error message will be added.
' * SheetName() is an array of worksheet names.
Dim ErrorMsg As String
Dim FoundError As Boolean
Dim FoundSheet() As Boolean
Dim FoundSheetsCount As Long
Dim InxName As Long
Dim InxWsheet As Long
Dim NotFoundSheetsCount As Long
Dim RowErrorNext As Long
Dim SheetNamesFound As String
' Size FoundSheet to match SheetName. Array elements initialised to False
ReDim FoundSheet(LBound(SheetName) To UBound(SheetName))
FoundSheetsCount = 0
NotFoundSheetsCount = 0
With WbookTgt
For InxName = LBound(SheetName) To UBound(SheetName)
NotFoundSheetsCount = NotFoundSheetsCount + 1 ' Assume not found until found
For InxWsheet = 1 To .Worksheets.Count
If SheetName(InxName) = .Worksheets(InxWsheet).Name Then
FoundSheet(InxName) = True
FoundSheetsCount = FoundSheetsCount + 1
NotFoundSheetsCount = NotFoundSheetsCount - 1
Exit For
End If
Next
Next
End With
If NotFoundSheetsCount = 0 Then
CheckWorksheets = True
Exit Function
End If
SheetNamesFound = ""
ErrorMsg = WbookTgt.Path & "\" & WbookTgt.Name & " does not contain "
If NotFoundSheetsCount = 1 Then
ErrorMsg = ErrorMsg & "this expected worksheet:"
Else
ErrorMsg = ErrorMsg & "these expected worksheets:"
End If
For InxName = LBound(SheetName) To UBound(SheetName)
If Not FoundSheet(InxName) Then
ErrorMsg = ErrorMsg & vbLf & " " & SheetName(InxName)
Else
SheetNamesFound = SheetNamesFound & vbLf & " " & SheetName(InxName)
End If
Next
If FoundSheetsCount = 0 Then
' No need to add list of found sheet names
Else
ErrorMsg = ErrorMsg & vbLf & "but does contain "
If FoundSheetsCount = 1 Then
ErrorMsg = ErrorMsg & "this expected worksheet:"
Else
ErrorMsg = ErrorMsg & "these expected worksheets:"
End If
ErrorMsg = ErrorMsg & SheetNamesFound
End If
With WbookError
With .Worksheets("Errors")
RowErrorNext = .Cells(Rows.Count, "A").End(xlUp).Row + 1
With .Cells(RowErrorNext, "A")
.Value = Now()
.VerticalAlignment = xlTop
End With
.Cells(RowErrorNext, "B").Value = ErrorMsg
End With
End With
CheckWorksheets = False
End Function
Function OpenWorkbook(ByVal Path As String, ByVal FileTemplate As String, _
ByRef WbookError As Workbook) As Workbook
' * If Path & FileTemplate identifies a single workbook, open it and return
' it as an object. If Path & FileTemplate does not represent a single
' workbook, report the problem in worksheet Errors and return Nothing.
' * WbookError identifies the workbook containing worksheet "Error".
' * Path must be the name of the folder in which the required workbook is located
' * FileTemplate can either be a specific filename or can contain wild cards
' providing only one file matches the template.
' * WbookError identifies the workbook containing worksheet "Error" to which any
' error message will be added.
Dim ErrorMsg As String
Dim FileNameCrnt As String
Dim FileNameMatch As String
Dim RowErrorNext As Long
FileNameMatch = Dir$(Path & "\" & FileTemplate, vbNormal)
If FileNameMatch = "" Then
' No matches found
ErrorMsg = "Template " & Path & "\" & FileTemplate & " does not match any file"
Else
' At least one match.
' If only one match, its name is in FileNameMatch
Do While True
FileNameCrnt = Dir$
If FileNameCrnt = "" Then
' No more matches
Exit Do
End If
' A second or subsequent match has been found.
If FileNameMatch <> "" Then
' This is the second match.
' Initialise error message and report name of first match
ErrorMsg = "Template " & Path & "\" & FileTemplate & " matches more than one file:" & _
vbLf & " " & FileNameMatch
FileNameMatch = "" ' No single match
End If
' Add name of current match to error message
ErrorMsg = ErrorMsg & vbLf & " " & FileNameCrnt
Loop
End If
If FileNameMatch = "" Then
' No single match found.
' ErrorMsg contains an appropriate error message
With WbookError
With .Worksheets("Errors")
RowErrorNext = .Cells(Rows.Count, "A").End(xlUp).Row + 1
With .Cells(RowErrorNext, "A")
.Value = Now()
.VerticalAlignment = xlTop
End With
.Cells(RowErrorNext, "B").Value = ErrorMsg
Set OpenWorkbook = Nothing
End With
End With
Else
' Single match found
Set OpenWorkbook = Workbooks.Open(Path & "\" & FileNameMatch)
End If
End Function
Response to extra question
VBA has nothing quite as convenient as VB's Try but it does have some error handling under programmer control.
If you use a command such as:
Worksheets("Sheet2").Delete
the user will be asked to confirm the deletion. To avoid this, use:
Application.DisplayAlerts = False
Worksheets("Sheet2").Delete
Application.DisplayAlerts = True
I have seen code with Application.DisplayAlerts = False at the start of a macro which means no alert will be displayed for the user's attention even if the pogrammer was not expecting it. By bracketing the Delete, I ensure only the alert I was expecting is suppressed.
Consider:
Sub OpenFile()
Dim InputFileNum As Long
InputFileNum = FreeFile
Open "Dummy.txt" For Input As InputFileNum
Debug.Print "File successfully opened"
Close InputFileNum
End Sub
The file "Dummy.txt" does not exist so the macro will stop on the Open statement.
You will sometimes see code like this:
Sub OpenFile()
Dim InputFileNum As Long
On Error GoTo ErrorCode
InputFileNum = FreeFile
Open "Dummy.txt" For Input As InputFileNum
Call MsgBox("File successfully opened", vbOKOnly)
Close InputFileNum
Exit Sub
ErrorCode:
Debug.Print "Unexpected error: " & Err.Number & " " & Err.Description
End Sub
Here I have provided a general handler for any error condition that may occur. I do not approve although I accept that this is slightly better than having the non-technical user seeing the faulty statement highlighted. The trouble is any error will result in the same unhelpful error message.
I never include error handling during development. If an error occurs, I want the macro to stop on the faulty statement so I can consider how to avoid the error. Here I should check the file exists before attempting to open it. I prefer something like this:
Sub OpenFile()
Dim FileSysObj As Object
Dim InputFileNum As Long
On Error GoTo ErrorCode
Set FileSysObj = CreateObject("Scripting.FileSystemObject")
If Not FileSysObj.FileExists("Dummy.txt") Then
Call MsgBox("I am unable to find ""Dummy.txt"". List of helpful suggestions.", vbOKOnly)
Exit Sub
End If
InputFileNum = FreeFile
Open "Dummy.txt" For Input As InputFileNum
Call MsgBox("File successfully opened", vbOKOnly)
Close InputFileNum
Exit Sub
ErrorCode:
Debug.Print "Unexpected error: " & Err.Number & " " & Err.Description
End Sub
I have including checking code for the error I expect. If the file does not exist, I have displayed a message which I hope will help the user fix the problem for themselves.
Sometimes you cannot avoid an error. To test the code below, I created file Dummy.txt but set the "Read access denied" flag. There is no easy method (to my knowledge) for a VBA macro to test this flag. I have a general handler for unexpected errors but I switch it off for the Open statment so I can include specific code for open failures. I have removed the code that uses FileExists() to test if Dummy.txt exists because it is easier to include it with the other open file error tests.
Sub OpenFile()
Dim FileSysObj As Object
Dim InputFileNum As Long
On Error GoTo ErrorCode ' General handler for unexpected errors
InputFileNum = FreeFile
Err.Clear
On Error Resume Next ' Record error in Err object and continue
Open "Dummy.txt" For Input As InputFileNum
Select Case Err.Number
Case 0
' No error.
Case 53 ' File does not exist
Call MsgBox("I am unable to find ""Dummy.txt"". List of helpful suggestions.", vbOKOnly)
Exit Sub
Case 75 ' Path/File access error
Call MsgBox("It appears file ""Dummy.txt"" exists but I do not have permission to read it.", vbOKOnly)
Exit Sub
Case Else
Call MsgBox("My attempt to open ""Dummy.txt"" failed with an unexpected error condition" & vbLf & _
" " & Err.Number & " " & Err.Description, vbOKOnly)
Exit Sub
End Select
On Error GoTo ErrorCode ' Restore general handler for unexpected errors
Call MsgBox("File successfully opened", vbOKOnly)
Close InputFileNum
Exit Sub
ErrorCode:
Debug.Print "Unexpected error: " & Err.Number & " " & Err.Description
End Sub
Visit http://support.microsoft.com/kb/146864 for a long list of error codes and more information about error handling.