Thursday, 11 January 2018

VBA - WorkbookGuts class - open up an Excel workbook by unzipping, and prettify any xml therein

So a Microsoft Excel workbook .xlsx or .xlsm is in fact a zipped file and here I give code that allows the unzipping and inspection of the contents therein. I have a class to give in this post but also use classes given in the previous two posts, so if you think code is missing then look to prior posts

Dependencies

The two other classes required to complete this project are the RecursiveXmlPrettifier class and the RecursiveExplorerWindows class. These classes allow us to explore all the sub directories in the unzipped folder as well as prettify any Xml files therein.

The two type library dependencies are Microsoft Scripting Runtime for file operations and Microsoft Shell Controls and Automation for (un)zipping a file.

With Thanks to Ron deBruin - NewZip

There is an absolute gem borrowed from Ron deBruin at https://www.rondebruin.nl which creates a new zip file directly from a sequence of bytes. Fantastic!

How to use this - instructions for demo

The code in the test module illustrate the two main methods on the WorkbookGuts class, open and close. But also given in the test code is logic to open up all the windows and also the prettify the xml files. Without the prettification of the xml files they would not be readable in Notepad, one would have to open them up in Visual Studio and say Format Document which would be a pain.

There is documentation for this directory structure at Microsoft's Open Xml SDK 2.5 for Office.

Future Posts

I will post further on this zip format. I will comment how I think it is quite complicated if not too complicated. I will also post on Microsoft's Open Xml SDK 2.5 for Office and contrast its complexity with the simplicity of VBA. As an epilogue to that series of posts, I will compare this serialization format with that of Google Sheets which seems tons simpler.


The WorkbookGuts class


Option Explicit

'*Tools->References
'* Microsoft Scripting Runtime                      C:\Windows\sysWOW64\scrrun.dll
'* Microsoft Shell Controls and Automation          C:\Windows\sysWOW64\shell32.dll



Private mfso As New Scripting.FileSystemObject

Public bDebug As Boolean
Public bVerbose As Boolean

Friend Function ApplicationDirectory() As String
    
    Dim sApplicationDirectory As String
    sApplicationDirectory = mfso.BuildPath(Environ$("TMP"), "VBAEquivOfOpenXML")
    
    If Not mfso.FolderExists(sApplicationDirectory) Then mfso.CreateFolder (sApplicationDirectory)
    
    ApplicationDirectory = sApplicationDirectory

End Function

Friend Function ExtractFolder(ByVal sWookbookName As String) As String

    If mfso.FileExists(sWookbookName) Then
        
        Dim filWorkbook As Scripting.File
        Set filWorkbook = mfso.GetFile(sWookbookName)
        
        ExtractFolder = mfso.BuildPath(ApplicationDirectory, Split(filWorkbook.Name, ".")(0))
    End If

End Function


Friend Function LeafName(ByVal sWookbookName As String) As String

    If mfso.FileExists(sWookbookName) Then
        Dim filWorkbook As Scripting.File
        Set filWorkbook = mfso.GetFile(sWookbookName)
    
        LeafName = filWorkbook.Name
    End If
    
    Debug.Assert VBA.InStr(1, LeafName, "\", vbTextCompare) = 0
    
End Function

Friend Function LeafNameToZip(ByVal sWookbookName As String) As String
    Dim sLeafName As String
    sLeafName = LeafName(sWookbookName)
    
    LeafNameToZip = VBA.Replace(VBA.Replace(sLeafName, ".xlsm", ".zip"), ".xlsx", ".zip")
End Function



Public Sub CloseTheGutsOfTheWorbook(ByVal sWookbookName As String, Optional sNewWorkbookName As String = "")

    On Error GoTo ErrHandler

    If LenB(sNewWorkbookName) = 0 Then sNewWorkbookName = sWookbookName

    If mfso.FileExists(sWookbookName) Then
        
        Dim filWorkbook As Scripting.File
        Set filWorkbook = mfso.GetFile(sWookbookName)
        
        Dim sApplicationDirectory As String
        sApplicationDirectory = ApplicationDirectory
    
        Dim sWorkbookZip As String
        sWorkbookZip = mfso.BuildPath(sApplicationDirectory, LeafNameToZip(sWookbookName))
    
        With New Shell32.Shell
            
            Dim sExtractFolder As String
            sExtractFolder = mfso.BuildPath(sApplicationDirectory, Split(filWorkbook.Name, ".")(0))
            
            If mfso.FileExists(sWorkbookZip) Then Call mfso.DeleteFile(sWorkbookZip, True)
            
            NewZip sWorkbookZip
            Debug.Assert mfso.FileExists(sWorkbookZip)
            'Call mfso.CreateFile(sWorkbookZip)
            
            Dim oExtractFolderNamespace As Shell32.Folder
            Set oExtractFolderNamespace = .Namespace(sExtractFolder)

            '.Namespace(sWorkbookZip).CopyHere .Namespace(sExtractFolder).Items
            
            Dim oZippedFileNamespace As Shell32.Folder
            Set oZippedFileNamespace = .Namespace(sWorkbookZip)
            
            oZippedFileNamespace.CopyHere oExtractFolderNamespace.Items
            
            
            
            '* above line is multi-threaded it seems, need to wait
            While oZippedFileNamespace.Items.Count <> oExtractFolderNamespace.Items.Count
                DoEvents
                Application.Wait CDate(Now() + CDate("00:00:01"))
                DoEvents
            Wend
        End With
        
        'CopyFileEH sWorkbookZip, sNewWorkbookName
        mfso.CopyFile sWorkbookZip, sNewWorkbookName
    End If

SingleExit:
    Exit Sub
    
ErrHandler:
    If bDebug Then
        Stop
        Resume
    Else
        Err.Raise Err.Number, Err.Source, Err.Description
    End If


End Sub

'* https://www.rondebruin.nl/win/s7/win001.htm
'* With thanks to Ron deBruin @ https://www.rondebruin.nl
Private Sub NewZip(ByVal sPath As String)
    'Create empty Zip File
    'Changed by keepITcool Dec-12-2005
    If Len(Dir(sPath)) > 0 Then Kill sPath
    Open sPath For Output As #1
    Print #1, Chr$(80) & Chr$(75) & Chr$(5) & Chr$(6) & String(18, 0)
    Close #1
End Sub


Public Function OpenTheGutsOfTheWorbook(ByVal sWookbookName As String, ByVal oPrettifyXml As RecursiveXmlPrettifier) As String
    
    On Error GoTo ErrHandler
    
    If mfso.FileExists(sWookbookName) Then
    
        Dim filWorkbook As Scripting.File
        Set filWorkbook = mfso.GetFile(sWookbookName)
    
        Dim sApplicationDirectory As String
        sApplicationDirectory = ApplicationDirectory
        
        
        Dim sWorkbookZip As String
        sWorkbookZip = mfso.BuildPath(sApplicationDirectory, LeafNameToZip(sWookbookName))
        
        mfso.CopyFile sWookbookName, sWorkbookZip

        With New Shell32.Shell

            '* Introduction to the Shell Namespace
            '* https://msdn.microsoft.com/en-us/library/windows/desktop/cc144090(v=vs.85).aspx
            Dim oFolder As Shell32.Folder
            Set oFolder = .Namespace(sApplicationDirectory)
            
            Dim oFolderItem As Shell32.FolderItem
            Set oFolderItem = oFolder.ParseName(filWorkbook.Name)
            
            Dim sExtractFolder As String
            sExtractFolder = mfso.BuildPath(sApplicationDirectory, Split(filWorkbook.Name, ".")(0))
            
            If mfso.FolderExists(sExtractFolder) Then Call mfso.DeleteFolder(sExtractFolder)
            If Not mfso.FolderExists(sExtractFolder) Then CreateFolderMultipleAttempts sExtractFolder  ' mfso.CreateFolder sExtractFolder
            Debug.Assert mfso.FolderExists(sExtractFolder)
            
            .Namespace(sExtractFolder).CopyHere .Namespace(sWorkbookZip).Items
            
            OpenTheGutsOfTheWorbook = sExtractFolder '* so the caller can shell explorer too
            
            If Not oPrettifyXml Is Nothing Then
                oPrettifyXml.PrettyPrintAllInFolder sExtractFolder
            
            End If
            
        End With

    End If
    
SingleExit:
    Exit Function
    
ErrHandler:
    If bDebug Then
        Stop
        Resume
    Else
        Err.Raise Err.Number, Err.Source, Err.Description
    End If

End Function


Function CreateFolderMultipleAttempts(ByVal sFolder As String)
    
    On Error GoTo ErrHandler
    
    Dim dtInterval As Date
    dtInterval = Interval(1)
    
    Const lMaxAttempts As Long = 3

    Dim lAttempts As Long
    lAttempts = 0

Retry:
    On Error Resume Next
    
    If lAttempts < lMaxAttempts Then
        lAttempts = lAttempts + 1
        If bVerbose Then Debug.Print "Attempting (" & lAttempts & " of " & lMaxAttempts & ") to call [" & TypeName(mfso) & "].CreateFolder"
        
        '**********************************************************************************************************************************
        '* CORE OPERATION
        '**********************************************************************************************************************************
        mfso.CreateFolder sFolder
        '**********************************************************************************************************************************
        '* END OF CORE OPERATION
        '**********************************************************************************************************************************
        
    End If

    If Err.Number <> 0 Then
        If lAttempts < lMaxAttempts Then
            '* still have some goes left, report (of verbose) then wait
            If bVerbose Then Debug.Print "(" & Err.Number & ") " & Err.Description & " whilst attempting to call [" & TypeName(mfso) & "].CreateFolder"
    
            If dtInterval > 0 Then
                If bVerbose Then Debug.Print "reattempting after interval " & VBA.FormatDateTime(dtInterval)
                Application.Wait Now() + dtInterval
            End If
            Err.Clear
    
            GoTo Retry
        Else
            '* no more attempts left, throw to caller
            On Error GoTo 0
            Err.Raise Err.Number, Err.Source, Err.Description
        End If
    End If

SingleExit:
    Exit Function
    
ErrHandler:
    If bDebug Then
        Debug.Print "step-thru: (" & Err.Number & ") " & Err.Description & " whilst attempting to create folder '" & sFolder & "'"
        Stop
        Resume
    Else
        Err.Raise Err.Number, Err.Source, Err.Description
    End If
End Function

Private Function Interval(ByVal lIntervalSeconds As Long) As Date
    
    Dim lHours As Long
    lHours = lIntervalSeconds \ 3600
    
    Dim lMinutes As Long
    lMinutes = (lIntervalSeconds Mod 3600) \ 60
    
    Dim lSeconds As Long
    lSeconds = (lIntervalSeconds Mod 3600) Mod 60
    
    Dim sInterval As String
    sInterval = Right$("00" & lHours, 2) & ":" & Right$("00" & lMinutes, 2) & ":" & Right$("00" & lSeconds, 2)


    Interval = CDate(sInterval)
End Function

The tstTestWorkbookGuts standard (test) module


Option Explicit
Option Private Module

'*Tools->References
' *** Microsoft Scripting Runtime


Private Const msBOOKNAME As String = "n:\WorkbookGuts\Book1.xlsx"

Private mfso As New Scripting.FileSystemObject


Sub TestOpenTheGutsOfTheWorbook()
    Dim oGuts As WorkbookGuts
    Set oGuts = New WorkbookGuts
    
    oGuts.bDebug = True
    
    Dim oRecursiveExplorerWindows As RecursiveExplorerWindows
    Set oRecursiveExplorerWindows = New RecursiveExplorerWindows
    
    Debug.Assert oGuts.ExtractFolder(msBOOKNAME) = Environ$("userprofile") & "\AppData\Local\Temp\VBAEquivOfOpenXML\Book1"
    
    '* close off windows that will prevent the extract operation
    oRecursiveExplorerWindows.CloseFolderAndAllSubfolder oGuts.ExtractFolder(msBOOKNAME)
    
    
    Dim oRecursiveXmlPrettifier As RecursiveXmlPrettifier
    Set oRecursiveXmlPrettifier = New RecursiveXmlPrettifier
    
    
    Dim sTempDir As String
    sTempDir = oGuts.OpenTheGutsOfTheWorbook(msBOOKNAME, oRecursiveXmlPrettifier)
    
    oRecursiveExplorerWindows.OpenFolderAndAllSubfolder sTempDir

    Debug.Print "TestOpenTheGutsOfTheWorbook"

End Sub

Sub TestCloseTheGutsOfTheWorbook()
    Dim oGuts As WorkbookGuts
    Set oGuts = New WorkbookGuts
    
    
    Const sRETURNED As String = "Book1 returned.xlsx"
    Dim sReturnedWorkbook As String
    sReturnedWorkbook = VBA.Replace(msBOOKNAME, "Book1.xlsx", sRETURNED)
    
    On Error Resume Next
    Dim wbReturnedWorkbook As Excel.Workbook
    Set wbReturnedWorkbook = Application.Workbooks.Item(sRETURNED)
    On Error GoTo 0
    
    Debug.Assert wbReturnedWorkbook Is Nothing '<-- returned workbook should be closed otherwise permission denied
    
    oGuts.bDebug = True
    oGuts.CloseTheGutsOfTheWorbook msBOOKNAME, sReturnedWorkbook

    Debug.Print "TestCloseTheGutsOfTheWorbook"
End Sub

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