Excel Automation

Here is the few functions to automate the excel application.

'To Open a Microsoft Excel application with default new work book

Function CreateExcel()
Dim excelSheet
Set ExcelApp = CreateObject("Excel.Application") 'Create a new Microsoft Excel object
ExcelApp.Workbooks.Add
ExcelApp.Visible = True
Set CreateExcel = ExcelApp
End Function

'To Close the given Microsoft Excel document

Sub CloseExcel(ExcelApp)
Set excelSheet = ExcelApp.ActiveSheet
Set excelBook = ExcelApp.ActiveWorkbook
Set fso = CreateObject("Scripting.FileSystemObject")
On Error Resume Next
fso.CreateFolder "C:\Temp"
fso.DeleteFile "C:\Temp\ExcelExamples.xls"
excelBook.SaveAs "C:\Temp\ExcelExamples.xls"
ExcelApp.Quit
Set ExcelApp = Nothing
Set fso = Nothing
Err = 0
On Error GoTo 0
End Sub

'The SaveWorkbook method saves a workbook according to the workbook identifier.
'The method overwrites the previously saved file in the given path.
'excelApp - a reference to the Microsoft Excel application
'workbookIdentifier - The name or number of the requested workbook
'path - The location to which the workbook should be saved
'Returns "OK" on success and "Bad Workbook Identifier" on failure

Function SaveWorkbook(ExcelApp, workbookIdentifier, path) 'As String
Dim workbook 'As Excel.workbook
On Error Resume Next
Set workbook = ExcelApp.Workbooks(workbookIdentifier)
On Error GoTo 0
If Not workbook Is Nothing Then
Set fso = CreateObject("Scripting.FileSystemObject")
'If the path has no file extension then add the 'xls' extension
If InStr(path, ".") = 0 Then
path = path & ".xls"
End If
On Error Resume Next
fso.DeleteFile path
Set fso = Nothing
Err = 0
On Error GoTo 0
workbook.SaveAs path
SaveWorkbook = "OK"
Else
SaveWorkbook = "Bad Workbook Identifier"
End If
End Function

'The SetCellValue method sets the given 'value' in the cell which is identified by
'its row, column, and parent Microsoft Excel sheet
'excelSheet - The Microsoft Excel sheet that is the parent of the requested cell
'row - the cell's row in the excelSheet
'column - the cell's column in the excelSheet
'value - the value to be set in the cell

Sub SetCellValue(excelSheet, row, column, value)
On Error Resume Next
excelSheet.Cells(row, column) = value
On Error GoTo 0
End Sub

'The GetCellValue returns the cell's value according to its row, column, and sheet
'excelSheet - The Microsoft Excel sheet in which the cell exists
'row - The cell's row
'column - The cell's column
'return 0 if the cell cannot be found

Function GetCellValue(excelSheet, row, column)
value = 0
Err = 0
On Error Resume Next
tempValue = excelSheet.Cells(row, column)
If Err = 0 Then
value = tempValue
Err = 0
End If
On Error GoTo 0
GetCellValue = value
End Function

'The GetSheet method returns a Microsoft Excel sheet according to the sheet Identifier
'ExcelApp - The Microsoft Excel application which is the parent of the requested sheet
'sheetIdentifier - The name or the number of the requested Microsofr Excel sheet
'return Nothing on failure

Function GetSheet(ExcelApp, sheetIdentifier) 'As Excel.worksheet
On Error Resume Next
Set GetSheet = ExcelApp.Worksheets.Item(sheetIdentifier)
On Error GoTo 0
End Function

'The InsertNewWorksheet method inserts a new worksheet into the active workbook or
'the workbook identified by the workbookIdentifier. The new worksheet will get a default
'name if the sheetName parameter is empty, otherwise the sheet has the sheetName
'as its name.
'Return - The new sheet as an object
'ExcelApp - The Microsoft Excel application object into which the new worksheet should be added
'workbookIdentifier - An optional identifier of the worksheet into which the new worksheet should be added
'sheetName - The optional name of the new worksheet.

Function InsertNewWorksheet(ExcelApp, workbookIdentifier, sheetName) 'As Excel.worksheet
Dim workbook 'As Excel.workbook
Dim worksheet 'As Excel.worksheet
'If the workbookIdentifier is empty, work on the active workbook
If workbookIdentifier = "" Then
Set workbook = ExcelApp.ActiveWorkbook
Else
On Error Resume Next
Err = 0
Set workbook = ExcelApp.Workbooks(workbookIdentifier)
If Err <> 0 Then
Set InsertNewWorksheet = Nothing
Err = 0
Exit Function
End If
On Error GoTo 0
End If
sheetCount = workbook.Sheets.Count
workbook.Sheets.Add , sheetCount
Set worksheet = workbook.Sheets(sheetCount + 1)
'If the sheetName is not empty, set the new sheet's name to sheetName
If sheetName <> "" Then
worksheet.Name = sheetName
End If
Set InsertNewWorksheet = worksheet
End Function

'The RenameWorksheet method renames a worksheet'
'ExcelApp - The Microsoft Excel application that is the worksheet's parent
'workbookIdentifier - The worksheet's parent workbook identifier
'worksheetIdentifier - The worksheet's identifier
'sheetName - The new name for the worksheet

Function RenameWorksheet(ExcelApp, workbookIdentifier, worksheetIdentifier, sheetName) 'As String
Dim workbook 'As Excel.workbook
Dim worksheet 'As Excel.worksheet
On Error Resume Next
Err = 0
Set workbook = ExcelApp.Workbooks(workbookIdentifier)
If Err <> 0 Then
RenameWorksheet = "Bad Workbook Identifier"
Err = 0
Exit Function
End If
Set worksheet = workbook.Sheets(worksheetIdentifier)
If Err <> 0 Then
RenameWorksheet = "Bad Worksheet Identifier"
Err = 0
Exit Function
End If
worksheet.Name = sheetName
RenameWorksheet = "OK"
End Function

'The RemoveWorksheet method removes a worksheet from a workbook
'ExcelApp - The Microsoft Excel application that is the worksheet's parent
'workbookIdentifier - The worksheet's parent workbook identifier
'worksheetIdentifier - The worksheet's identifier

Function RemoveWorksheet(ExcelApp, workbookIdentifier, worksheetIdentifier) 'As String
Dim workbook 'As Excel.workbook
Dim worksheet 'As Excel.worksheet
On Error Resume Next
Err = 0
Set workbook = ExcelApp.Workbooks(workbookIdentifier)
If Err <> 0 Then
RemoveWorksheet = "Bad Workbook Identifier"
Exit Function
End If
Set worksheet = workbook.Sheets(worksheetIdentifier)
If Err <> 0 Then
RemoveWorksheet = "Bad Worksheet Identifier"
Exit Function
End If
worksheet.Delete
RemoveWorksheet = "OK"
End Function

'The CreateNewWorkbook method creates a new workbook in the Microsoft Excel application
'ExcelApp - The Microsoft Excel application to which an new Microsoft Excel workbook will be added

Function CreateNewWorkbook(ExcelApp)
Set NewWorkbook = ExcelApp.Workbooks.Add()
Set CreateNewWorkbook = NewWorkbook
End Function

'The OpenWorkbook method opens a previously saved Microsoft Excel workbook and adds it to the Application
'excelApp - The Microsoft Excel application to which the workbook will be added.
'path - The path of the workbook that will be opened
'Returns Nothing on failure

Function OpenWorkbook(ExcelApp, path)
On Error Resume Next
Set NewWorkbook = ExcelApp.Workbooks.Open(path)
Set OpenWorkbook = NewWorkbook
On Error GoTo 0
End Function

'The ActivateWorkbook method sets one of the workbooks in the application as the active workbook
'ExcelApp - The workbook's parent Microsft Excel application
'workbookIdentifier - The name or the number of the workbook

Sub ActivateWorkbook(ExcelApp, workbookIdentifier)
On Error Resume Next
ExcelApp.Workbooks(workbookIdentifier).Activate
On Error GoTo 0
End Sub

'The CloseWorkbook method closes an open workbook
'ExcelApp - The parent Microsoft Excel application of the workbook
'workbookIdentifier - The name or the number of the workbook

Sub CloseWorkbook(ExcelApp, workbookIdentifier)
On Error Resume Next
ExcelApp.Workbooks(workbookIdentifier).Close
On Error GoTo 0
End Sub

'The CompareSheets method compares two sheets.
'If there is a difference between the two sheets then the value in the second sheet
'will be changed to red and contain the string:
'Compare conflict - Value was 'Value2', Expected value is 'value2'"
'sheet1, sheet2 - The Microsoft Excel sheets to be compared
'startColumn - The column to start comparing in the two sheets
'numberOfColumns - The number of columns to be compared
'startRow - The row to start comparing in the two sheets
'numberOfRows - The number of rows to be compared

Function CompareSheets(sheet1, sheet2, startColumn, numberOfColumns, startRow, numberOfRows, trimed) 'As Boolean
Dim returnVal 'As Boolean
returnVal = True
'If one of the sheets does not exist, do not continue the process
If sheet1 Is Nothing Or sheet2 Is Nothing Then
CompareSheets = False
Exit Function
End If
'Loop through the table and fill values into the two worksheets
For r = startRow to (startRow + (numberOfRows - 1))
For c = startColumn to (startColumn + (numberOfColumns - 1))
Value1 = sheet1.Cells(r, c)
Value2 = sheet2.Cells(r, c)
'If 'trimed' equals True then user wants to ignore blank spaces
If trimed Then
Value1 = Trim(Value1)
Value2 = Trim(Value2)
End If
'if the values of a cell are not equal in the two worksheets
'create an indicator that the values are not equal and set the return value
'to False
If Value1 <> Value2 Then
Dim cell 'As Excel.Range
sheet2.Cells(r, c) = "Compare conflict - Value was '" & Value2 & "', Expected value is '" & Value1 & "'."
Set cell = sheet2.Cells(r, c)
cell.Font.Color = vbRed
returnVal = False
End If
Next
Next
CompareSheets = returnVal
End Function

'***********************************************
'Main Script which calls all above the functions.

Dim ExcellApp 'As Excel.Application
Dim excelSheet1 'As Excel.worksheet
Dim excelSheet2 'As Excel.worksheet
Set ExcelApp = CreateExcel()
'Create a workbook with two worksheets
ret = RenameWorksheet(ExcelApp, "Book1", "Sheet1", "Example1 Sheet Name")
ret = RenameWorksheet(ExcelApp, "Book1", "Sheet2", "Example2 Sheet Name")
'Save as the workbook under a different name
ret = SaveWorkbook(ExcelApp, "Book1", "E:\Example1.xls")
'Fill the worksheets
Set excelSheet1 = GetSheet(ExcelApp, "Example1 Sheet Name")
Set excelSheet2 = GetSheet(ExcelApp, "Example2 Sheet Name")
For column = 1 to 10
For row = 1 to 10
SetCellValue excelSheet1, row, column, row + column
SetCellValue excelSheet2, row, column, row + column
Next
Next
'Compare the two worksheets
ret = CompareSheets(excelSheet1, excelSheet2, 1, 10, 1, 10, False)
If ret Then
MsgBox "The two worksheets are identical"
End If
'Change the values in one sheet
SetCellValue excelSheet1, 1, 1, "Yellow"
SetCellValue excelSheet2, 2, 2, "Hello"
'Compare the worksheets again
ret = CompareSheets(excelSheet1, excelSheet2, 1, 10, 1, 10, True)
If Not ret Then
MsgBox "The two worksheets are not identical"
End If
'Save the workbook by index identifier
SaveWorkbook ExcelApp, 1, ""
'Close the Microsoft Excel application
CloseExcel ExcelApp