"Object Variable Not Set" on IXMLDOMNode of MsXml-DOMDocument procedure

So I have this pretty large XML file (40MB) that I'll have to repeatedly search. I've been schooled on the benefits of DOMDocument usage with XPath, and I thought I had it right, but I'm getting the Obj Var Not Set nonsense.

Here's the initial load...I think its loading because it delays an appropriate length of time for a 40mb file & returns no error.

Dim someElement As IXMLDOMNode
Dim xmlDoc As Object
Set xmlDoc = CreateObject("Msxml2.DOMDocument.6.0")

'<-thats a valid file name lookup
xmlDoc.Load DLookup("gsgtver", "Eramdat", "EramID = 1") 

So heres where it gets dicey. I need a IXMLDOMNode to开发者_Python百科 read the parced xmlDoc object. I checked the MsXml 6.0 reference library, and I'm getting the var type when I dim (you know, the list of types that fill in for us noobs). And after I have a IXMLDOMNode set I get the list of methods (like ".text") when I try to assign, but I'm bangin on this error ..... could be a bum xpath string (although I pretty much verbatim stole it from the xpath tutorial).

sNodeName = "/Fix_Records/FixRecord/FixID[1]/Latitude"
Set someElement = xmlDoc.SelectSingleNode(sNodeName)

'yes, I dimmed xBuffer as a string up above
sBuffer = someElement.text 

Incedently, I REALLY wanna do a "FixID = 'mystring' " sorta thing, but I'm doing element 1 just to get it workin. And here's the top of the xml file:

<Fix_Records xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
             xsi:noNamespaceSchemaLocation="Fix.xsd"> 
 <!-- ******************************************************** -->
 <!-- Local SITE ID        : ZAB                               -->
 <!-- Local Release Version: a082a210                          -->
 <!-- NASD/NADR Version    : z084b210                          -->
 <!-- Date                 : 02-03-2011 19:02:56               -->
 <!-- ******************************************************** -->

    <FixRecord>
      <FixId>00BTR</FixId>
      <IcaoCode>K7</IcaoCode>
      <FixType>WAYPOINT</FixType>
      <FixName>BTR055100</FixName>
      <FixinUs>true</FixinUs>
      <IsNational>true</IsNational>
      <HighPowerVor>false</HighPowerVor>
      <DPositionMapData>false</DPositionMapData>
      <Latitude>31170205N</Latitude>
      <Longitude>089353453W</Longitude>
      <AngularCorr>-0.010472</AngularCorr>
      <XSpherical>0.006082693951808</XSpherical>
      <YSpherical>-0.85612436871425</YSpherical>
      <ZSpherical>0.516734038096893</ZSpherical>
    </FixRecord>
    <FixRecord>
      <FixId>00N10</FixId>
      <IcaoCode>MM</IcaoCode>

Thank you.....you smart people rock.

Your XPath is wrong. "/Fix_Records/FixRecord/FixID[1]/Latitude" means you're looking for the Latitude child element of the first FixID child element of THE FixRecord element.

But:

• There are many FixRecord elements,
• For any given FixRecord, there is only one FixId child element (no need to specify [1]), and
• Most importantly, FixId does not have a Latitude child element! So you're looking for something that isn't there, which is what is causing the error.
  • Also watch out for case sensitivity as pointed out by @James Walford. FixId not FixID

I think that what you want is: "/Fix_Records/FixRecord[1]/Latitude".

When you feel ready to go to the next level, try this:

"/Fix_Records/FixRecord[FixId='mystring']/Latitude".

If that doesn't work, there may be some namespace weirdness... Try adding xsi: before each node specification in the Xpath:

"/xsi:Fix_Records/xsi:FixRecord[1]/xsi:Latitude"
"/xsi:Fix_Records/xsi:FixRecord[xsi:FixId='mystring']/xsi:Latitude"

Keep up the spirits, you'll get there eventually!!

You have a case sensitive problem - you're looking for FixID, you've actually got FixId. When you try and access its text you throw an exception as you have no actual object.

EDIT: as pointed out by Jean-François Corbett, your XPath is also wrong. Here is an updated Xpath solving both problems:

"/Fix_Records/FixRecord[FixId='Id you want']/Latitude"

You may also want to test if you've got a node to access, see the answer below for some tips.

Once the XML is loaded, there's still a possibility of a parsing error. This code may help you to find where the problem lies. Change it accordingly to fit your environment.

The error numbers (6666) are obviously a joke, you must have proper err numbers for your application.

Edit: Also, try parse your XML (or at least part of it) in a XML validator, like http://www.validome.org/xml/validate/.

Public Sub readXMLDoc()

    Dim objXML As MSXML2.DOMDocument
    Dim lookupNode As MSXML2.IXMLDOMNode
    Dim vOut As Variant
    Dim sNodeName As String
    Dim sParseError As String


    On Error GoTo ProcError

    Set objXML = New MSXML2.DOMDocument

    objXML.async = False
    objXML.LoadXML "c:\XMLSample.xml"

    If objXML Is Nothing Then Err.Raise 6666, , "Error while opening the XML file"

    sParseError = objXML.parseError.reason

    If Len(sParseError) > 0 Then Err.Raise 6666, , "Error while parsing the XML file: " & sParseError

    sNodeName = "/Fix_Records/FixRecord/FixID[1]/Latitude"

    Set lookupNode = objXML.SelectSingleNode(sNodeName)

    If lookupNode.ChildNodes.Length > 0 Then

        'Do your handling

    End If

ProcExit:

    Exit Sub

ProcError:

    Debug.Assert False
    Debug.Print Err.Description
    Resume ProcExit

End Sub