By inspection, the breakdown of the file is as follows:    

A simple explanation of this XML is that it is a tree structure. The loc node is the base node of the tree, and everything else is a child node of it. The waypoints are one level below this. Each of the other nodes (name, coord, etc.) is a child node of the waypoint.

The MSXML object uses a zero-based system to refer to items within the XML tree. The first waypoint will be childnode(0). The second waypoint will be childnode(1). The attributes within each tag are also zero-based, so in the coord node, lat is attribute(0) and lon is attribute(1).

Note: In the Name node, the CDATA at the beginning of the text tells the parser that the following information is plain text and should not be marked up. It is handled automatically by the XML parser. The Waypoint ID (an attribute of this node) is assigned by the www.geocaching.com database and can be used as a simple identifier on a GPS. (Most GPS units do not allow you to use elaborate naming of waypoints.)

The COM Add-In

The COM Add-In should read the loc file and place a Pushpin on a MapPoint 2002 map for each waypoint. The Add-In should have a user interface where the user can indicate the location of the loc file and make selections about formatting, such as whether to display the headings and how to display the coordinates. The heading for the Pushpin should have the cache name and ID number. The description should contain the actual coordinates.

Creating a COM Add-In in Visual Basic has been explored in other articles. I used the information in Rich Born’s article "MapPoint Graticule COM Add-In" and from MSDN to develop this Add-In.

To get started:    

Option Explicit Public m_formDisplayed As Boolean Public g_oApp As MapPoint.Application Dim m_frmAddIn As New frmAddIn Sub Hide() '--Hides the form and remembers its state On Error Resume Next m_formDisplayed = False m_frmAddIn.Hide End Sub Sub Show() '--Shows the form and remembers its state On Error Resume Next If m_frmAddIn Is Nothing Then Set m_frmAddIn = New frmAddIn End If Set m_frmAddIn.g_oApp = g_oApp Set m_frmAddIn.Connect = Me m_formDisplayed = True m_frmAddIn.Show vbModal End Sub '------------------------------------------------ 'This method adds the Add-In to MapPoint '------------------------------------------------ Private Sub AddinInstance_OnConnection(ByVal Application As Object, ByVal ConnectMode As AddInDesignerObjects.ext_ConnectMode, _ ByVal AddInInst As Object, custom() As Variant) On Error GoTo error_handler 'Save the MapPoint instance Set g_oApp = Application '--The following has the name of the menu item that is added: g_oApp.AddCommand "Waypoint Importer", "Show", Me If ConnectMode = ext_cm_AfterStartup Then If GetSetting(App.Title, "Settings", "DisplayOnConnect", _ "0") = "1" Then 'Set this to display the form on connect Me.Show End If End If Exit Sub error_handler: MsgBox Err.Description End Sub '------------------------------------------------ 'This method removes the Add-In from MapPoint '------------------------------------------------ Private Sub AddinInstance_OnDisconnection(ByVal RemoveMode As AddInDesignerObjects.ext_DisconnectMode, custom() As Variant) On Error Resume Next 'Delete the commands that were added for this Add-In g_oApp.RemoveCommands Me Unload m_frmAddIn Set m_frmAddIn = Nothing End Sub

You will need a few references in the project, so add the following from the Project/References menu:    

I like to use the Common Dialog control to help manage anything to do with opening and saving files, so we’ll use it. From the Project/Components menu, add a reference to Microsoft Common Dialog.

We are now ready to get to the good stuff! Open the default form, frmAddIn and add the following to it:

   
• A textbox named txtPath to hold the path of the loc file.
   
• A Browse button named cmdBrowse, to browse for a file if you don’t know the path.
   
• An Import button named cmdImport, to start the import routine.
   
• A Cancel button named cmdCancel, to escape the Add-In.
   
• A common dialog control named CommonDialog1 to provide the browse functionality.
   
• A frame for controlling Pushpin Properties. In this frame, add the following three option buttons:
       
• optNone, with the caption set to “no caption”
       
• optTitle, with the caption set to “Title Only”
       
• optFull, with the caption set to “Full caption”
• A frame for selection of coordinate display. In this frame, add the following two option buttons:
       
• optCoordDecimal, with the caption set to “Decimal degrees”
       
• optionDMM, with the caption set to “Degree decimal minutes,” which is the format most geocachers use
   
• A checkbox named chkView to display a message box of information for every point imported.
• Labels for the above controls as needed for usability.
• For the option buttons, choose which one of each group should be the default, and set it’s value property to true

Here is the complete code for the form. I’ll talk about the details below.

'these are required for the "DESIGNER" Public Connect As Connect Public g_oApp As MapPoint.Application Option Explicit Private Sub CancelButton_Click() Connect.Hide End Sub Private Sub cmdBrowse_Click() CommonDialog1.Filter = _ "EasyGPS (*.loc)|*.loc|XML (*.xml)|*.xml|All (*.*)|*.*" CommonDialog1.ShowOpen txtPath.Text = CommonDialog1.FileName End Sub Private Sub cmdImport_Click() Dim xDoc As MSXML2.DOMDocument Dim mpApp As MapPoint.Application Dim mpMap As MapPoint.Map Dim mpPushpin As MapPoint.Pushpin Dim mpLocation As MapPoint.Location Dim lRecordCount As Long Dim nodelist As IXMLDOMNodeList Dim node As IXMLDOMNode Dim strName As String 'name of geocache Dim strID As String 'waypoint ID Dim dblLat As Double 'latitude Dim dblLong As Double 'longitude Dim strLink As String 'hyperlink to geocaching.com ‘Some simple error checking If CommonDialog1.FileName = "" Then MsgBox "You must select a file first!" Exit Sub End If 'initialize XML doc Set xDoc = New MSXML2.DOMDocument xDoc.Load (CommonDialog1.FileName) 'initialize MapPoint app Set mpApp = g_oApp 'New MapPoint.Application Set mpMap = mpApp.ActiveMap mpApp.Visible = True mpApp.UserControl = True 'loop through XML lRecordCount = xDoc.documentElement.childNodes.Length If lRecordCount > 0 Then 'read in the elements For Each node In xDoc.documentElement.childNodes If node.baseName = "waypoint" Then 'We are looking at a waypoint 'we know the child nodes follow the following pattern strName = node.childNodes(0).Text strID = node.childNodes(0). _ Attributes.Item(0).Text 'ID attribute dblLat = node.childNodes(1). _ Attributes.Item(0).Text 'Latitude dblLong = node.childNodes(1). _ Attributes.Item(1).Text strLink = node.childNodes(3).Text 'Add Pushpin Set mpPushpin = mpMap.AddPushpin( _ mpMap.GetLocation(dblLat, dblLong, 1), _ strID & " - " & strName) If optCoordDecimal Then 'display coorýýýý Decimal Degrees format mpPushpin.Note = CStr(dblLat) & ", " & _ CStr(dblLong) & vbCrLf & _ strLink Else 'diplay cood in Decimal minutes format mpPushpin.Note = MakeDecDeg(dblLat) & _ ", " & MakeDecDeg(dblLong) & vbCrLf & _ strLink End If mpPushpin.Symbol = 25 'Big RED Dot! See library at http://msdn.microsoft.com/ library/default.asp?url=/library/en-us/MapPoint/html/ BIZOMPSymbol.asp If optHeading Then mpPushpin.BalloonState = _ geoDisplayName 'heading only ElseIf optFull Then mpPushpin.BalloonState = _ geoDisplayBalloon Else mpPushpin.BalloonState = _ geoDisplayNone End If Set mpLocation = mpPushpin.Location mpLocation.GoTo If chkView Then MsgBox strName & vbCrLf & strID & _ vbCrLf & dblLat & vbCrLf & _ dblLong & vbCrLf & strLink End If End If Next End If 'cleanup Cleanup: Set xDoc = Nothing Connect.Hide Exit Sub err_import: MsgBox "Error: " & Err.Number & _ vbCrLf & Err.Description GoTo Cleanup End Sub Private Sub txtPath_Change() 'if typed in manually, update commondialog property If CommonDialog1.FileName <> txtPath.Text Then CommonDialog1.FileName = txtPath End If End Sub Private Function MakeDecDeg(dblDecimal As Double) As String 'convert decimal degrees into degrees, minutes decimal minutes 'Rahn Lieberman 10/21/02 from formula ‘at http://nris.state.mt.us/wis/location/LatLong.asp 'There is the occasional rounding error in the least significant digit Dim intDeg As Integer Dim dblMin As Double Dim dblTmp As Double Dim blnFlag As Boolean If dblDecimal < 0 Then 'if direction is S or W, convert to pos number ‘ and convert back later blnFlag = True dblDecimal = Abs(dblDecimal) End If intDeg = Int(dblDecimal) 'retrieve degrees dblTmp = dblDecimal - intDeg 'decimal fraction dblMin = dblTmp * 60 'fraction to decimal min 'round to 3 decimal places dblMin = (Int(dblMin * 1000)) / 1000 If blnFlag Then intDeg = 0 - intDeg MakeDecDeg = CStr(intDeg) & " " & CStr(dblMin) End Function