Comments on: Reading XML Files in VBA

By: david fischer

david fischer — Fri, 08 Apr 2011 10:49:00 +0000

If you want to pull in an XML Database you could also try using an XML Editor

By: Nigel

Nigel — Fri, 15 Oct 2010 17:11:00 +0000

Interesting stuff…

No-one uses the inbuilt parsing functions of Microsoft’s XML document objects if they can avoid it: go find a PERL or a Python developer and pay them some money. Or buy them beer, they don’t get out much.

That being said, we do still need to do this for ourselves from time to time, and I have some VBA lying around to do it. The problem is posting this stuff: Blogspot has issues with source code in general, XML in particular, and anything containing ‘>’ is going to be a major headache when the material is cleaned up for (say) RSS readers.

Let’s see how your custom tags cope with this…



'

' Sample Input file:

'

'  

'  

'       

'           FTSE

'           100

'           GBP

'       

'       

'           CAC40

'           40.6221038366675

'           USD

'       

'   

'

'

What we have here (if it’s loaded intellibly) is code to export and reload a very, very simple table: columns and rows, no nested data structure at all. 

Even this requires careful wrapping: if you’re lucky, you’ll get away with assuming that your XML-to-Excel parser doesn’t need to be told to look for a root element called FUND_SETUP (all XML files have a root element and I’m told that MS XMLDocument6 never fails to parse to parse it out and read the name) and you don’t need to look for the first-level element name as you get this for free in the ChildNodes collection…

I believe the guy who told me that. But I can see why Python programmers don’t get out much, and I now know why nobody ever buys them beer. Me, I specify the root element, and I specify the names of the elements I want to import.

This code’s taken from a ‘relation’ object: a class that wraps an array and allows us to refer to the rows and columns by name - so what you’ll see in the code sample below is an array (m_arrData), a dictionary of column names (m_dictCols) and a dictionary that acts as a row index (m_dictRows).

What you’ll also see is that there’s a lot of work in a very simple data structure: it’s not just the overhead in all the data-cleaning, no-one’s ever managed to code up an XML import-export library that is truly ‘generic’, even for plain-vanilla relational data.

'

'

'





Public Sub LoadFromXML(objXMLdocument6 As MSXML2.DOMDocument60, _

              Optional IndexColumnName As String = "", _

              Optional RootTag As String = "", _

              Optional RowTag As String = "", _

              Optional bIgnoreRowAttributes As Boolean = True, _

              Optional bUseFirstRowFormat As Boolean = True)

              

 On Error Resume Next

 

' This method will load tabular data from an XML file

' It is sensitive to file format, and will not accept all valid XML data:

' files: it expects that the XML file will represent simple tabular data



' Optional RootTag As String = ""

 ' Optional, identifies the parent node for the data table.

 ' By default, the root node of the XML document will be used

 

' Optional  RowTag As String = ""

 ' Optional, identifies the nodes or entities that we will use as rows in this relation

 ' By default, all child nodes of the root entity will be loaded as rows

 

' Optional  IndexColumnName As String = ""

 ' Optional, identifies the data 'column' we will use as the unique row identifier

 ' By default, the first attribute or the name of the first child node of the row entity will be used

 

' Optional  bIgnoreRowAttributes As Boolean

 ' Read the child nodes only, ignoring the attributes of the entities that define each row

 

' Optional  bUseFirstRowFormat As Boolean

  'Do not scan the entire document to determine the column list



' Duplicated Row ID's will be excluded from the final result: we

' only retain the row with the first occurrence of a given row ID





' Sample usage:

'

'    Dim objXMLdocument6 As MSXML2.DOMDocument60

'    Set objXMLdocument6 = New MSXML2.DOMDocument60

'    objXMLdocument6.Load "C:TempFund_setup.xml"

'

'    Dim relFund_Setup As clsRelation

'    Set relFund_Setup = New clsRelation

'    relETF_Setup.LoadFromXML objXMLdocument6, "ID", "FUND_SETUP", "FUND", False, True

'

' Sample Input file:

'

'  

'  

'       

'           FTSE

'           100

'           GBP

'       

'       

'           CAC40

'           40.6221038366675

'           USD

'       

'   





Dim oXMLattribute   As MSXML2.IXMLDOMAttribute

Dim oXMLnode        As MSXML2.IXMLDOMNode

Dim oXMLnodeRoot    As MSXML2.IXMLDOMNode

Dim oXMLnodeChild   As MSXML2.IXMLDOMNode

Dim oXMLnodeList    As MSXML2.IXMLDOMNodeList





Dim varData As Variant



Dim iRowCount As Integer

Dim iColCount As Integer

Dim iRow As Integer

Dim iCol As Integer

Dim i As Integer

Dim j As Integer

Dim strColName As String

Dim strRowID As String

 



    

    If RootTag = "" Then

        Set oXMLnodeRoot = Nothing

        Set oXMLnodeRoot = objXMLdocument6.selectNodes("/*").Item(0)

        RootTag = oXMLnodeRoot.baseName

    Else

        Set oXMLnodeList = objXMLdocument6.getElementsByTagName(RootTag)

        Set oXMLnodeRoot = oXMLnodeList.NextNode

    End If

    

    If oXMLnodeRoot Is Nothing Then

        GoTo ExitSub

    End If

    

    

    For Each oXMLattribute In oXMLnodeRoot.Attributes

        

        If Me.Attributes.Exists(oXMLattribute.Name) Then

            Me.Attributes(oXMLattribute.Name) = oXMLattribute.Value

        Else

            Me.Attributes.Add oXMLattribute.Name, oXMLattribute.Value

        End If

        

    Next ' oXMLattribute

    



    If Not oXMLnodeRoot.hasChildNodes Then

        GoTo ExitSub

    End If

    

    Set oXMLnodeList = Nothing

    If RowTag = "" Then

        Set oXMLnodeList = objXMLdocument6.selectNodes("./*/*")

    Else

        Set oXMLnodeList = objXMLdocument6.getElementsByTagName(RowTag)

    End If

    

    

    iRowCount = oXMLnodeList.Length

    

    If iRowCount = 0 Then

        GoTo ExitSub

    End If

            

    ' Two passes through the document:

    '   First pass, get the dimensions and column names;

    '   (this pass can be specified as 'use Row 1 only')

    '   Second pass, populate the relation's data array.

    

    Set m_dictCols = Nothing

    Set m_dictCols = New Scripting.Dictionary

    

    If IndexColumnName <> "" Then

        m_dictCols.Add IndexColumnName, 1

    End If

    

    For Each oXMLnode In oXMLnodeList

            

        If bIgnoreRowAttributes = False Then

            For Each oXMLattribute In oXMLnode.Attributes

                If Not m_dictCols.Exists(oXMLattribute.Name) Then

                    m_dictCols.Add oXMLattribute.Name, m_dictCols.Count + 1

                End If

            Next oXMLattribute

        End If

        

        For Each oXMLnodeChild In oXMLnode.childNodes

            

            If Not m_dictCols.Exists(oXMLnodeChild.nodeName) Then

                m_dictCols.Add oXMLnodeChild.nodeName, m_dictCols.Count + 1

            End If

                

        Next oXMLnodeChild

        

        If bUseFirstRowFormat Then

            Exit For

        End If

        

    Next

    

    If m_dictCols.Count = 0 Then

        GoTo ExitSub

    End If

    

    If IndexColumnName = "" Then

        IndexColumnName = m_dictCols.Keys(0)

    End If

            

 



    iColCount = m_dictCols.Count

    

    

    

    Set m_dictRows = New Scripting.Dictionary

    iRow = 0

    ReDim varData(1 To iRowCount, 1 To iColCount)

 

    

     For Each oXMLnode In oXMLnodeList

     iRow = iRow + 1

           

        If bIgnoreRowAttributes = False Then

        For Each oXMLattribute In oXMLnode.Attributes

        

            strColName = ""

            strColName = oXMLattribute.Name

            

            If m_dictCols.Exists(strColName) Then

                iCol = m_dictCols(strColName)

                varData(iRow, iCol) = oXMLattribute.Value

            End If

            

        Next oXMLattribute

        End If

        

        For Each oXMLnodeChild In oXMLnode.childNodes



By: Vikas
Vikas — Fri, 15 Oct 2010 08:34:00 +0000
Thank you very much for your post regarding reading XML file .
It is really usefull.


By: bj
bj — Fri, 26 Mar 2010 05:18:00 +0000
I even preceded it with ‘ that time and it still dissapeared. 
I’ll take the front bracket off the  line and try again so please remember to put it back on.  
?xml version=”1.0??>



By: bj
bj — Fri, 26 Mar 2010 05:16:00 +0000
Hmmm that was interesting... the xml code went into the html blackhole.
Here it is again:
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By: bj
bj — Fri, 26 Mar 2010 05:14:00 +0000
Hi guys.
I'm not new to VBA but I am to XML and the use of inbuilt parsers.
I am trying to parse an XML file but it is driving me nuts right now. I have an xml file, sampled as follows:
So far I can get the highest level node titles but not the "Categories" which I need and the best, neatest, smallest lot of code I have so far, in a day of looking, trying and modifying is the following:
Sub getWikiInfoViaXML()
    Dim xmlDoc As New DOMDocument

    Dim fileOK As Boolean

    Dim myNode As IXMLDOMElement

    Dim myCNode As IXMLDOMNode

    Dim a As Integer
    fileOK = xmlDoc.Load("FilePAthallPages.xml")
    a = 2

    If fileOK Then

        With Sheets("Wiki Source Docs")

            For Each myNode In xmlDoc.selectNodes("//page")

                .Cells(a, 1) = myNode.getAttribute("title")

                a = a + 1

            Next myNode

        End With

    Else

        MsgBox "Unable to open the file selected"

    End If

End Sub
Any help would be appreciated.
TIA.
Cheers,
BJ


By: Jon Peltier
Jon Peltier — Mon, 22 Jun 2009 01:46:00 +0000
I would have just said "code like mine".
I also thought I needed a variant for Split. I had to test it just now to check. No day is wasted if I learn something.


By: jeffrey weir
jeffrey weir — Sun, 21 Jun 2009 01:36:00 +0000
keepITCool: on a site dedicated to teaching, sharing, and community; I’m surprised you write ‘crappy’. Guess I must be an idealist too…



By: Dick Kusleika
Dick Kusleika — Sun, 21 Jun 2009 00:57:00 +0000
You're surprised I write crappy code?  You must be some kind of idealist.
I thought I had to use a Variant for Split.  That's a new one on me.  As for writing to cells in a loop, I never do that when it counts - I swear.


By: keepITcool
keepITcool — Sat, 20 Jun 2009 07:10:00 +0000
Dick,

As pointed out by others your use of XML has room for improvement. But on a site dedicated to Excel I'm amazed that you (and others) still write crappy code. 
IMHO Variants are only used when there's no alternative, code should run for non US separators and I never pump data to a sheet on a cell by cell basis. Following code does the same as yours, but is tidy. Example is latebound, so a reference to XML 3 or 6 is not needed.
Sub ReadStateXML()

Dim adList() As Double

Dim asText() As String

Dim sFile As String

Dim sXpath As String

Dim i As Long

Dim j As Long

  

  sFile = "C:UsersxxxDocuments1198.kml"



  'Reminder: XML is caseSensitive!

  sXpath = "//Placemark/MultiGeometry/Point/coordinates"

  

  With CreateObject("MSXML2.DOMDocument")

    Debug.Assert Len(Dir(sFile)) 'Check the file exists

    .Load sFile

    Debug.Assert .parseError.errorCode = 0

    With .documentElement.selectNodes(sXpath)

      Debug.Assert .Length

      ReDim adList(.Length - 1, 1)

      For i = 0 To .Length - 1

        asText = Split(.Item(i).Text, ",")

        For j = 0 To 1

          'Use Val not Cstr

          adList(i, j) = Val(asText(j))

        Next

      Next

      Range("A2").Resize(.Length, 2) = adList

    End With

  End With

  

End Sub