IXMLDOMNode.definition

[danjevans]

Sorry if this has been asked before or is just plain stupid, I'm new to all this.

After applying a Schema to an XMLDOMDocument40 object, I'm trying to work out which Schema rule has caused a failure. I can tell which element in the XML is wrong and want to use this to et the Schema rule that deals with it. I was under the impression that IXMLDOMNode.definition could do this but I can't for the life of me get it to work.

If anyone could post a short working example, I would be eternally grateful.

I'm using MSXML 4 and VB6.

Thanks in advance,

[MartinLiss]

There's some stuff in here that you have to change/remove but this is basically what you want to do.

Public Sub ValidateXML()
'***************************************************************************
'Purpose: Validate the modified xml file against the schema
'Inputs:  None
'Outputs: True if OK, False if not.
'***************************************************************************
 
    Dim oxmlSchema As MSXML2.XMLSchemaCache40
    Dim oxmlValidateDoc As MSXML2.DOMDocument40
    Dim strText As String
    Dim intIndex As Integer
    
    Screen.MousePointer = vbHourglass
    
    On Error GoTo ErrorRoutine
    
    'Create the schema cache and add the schema to it.
    Set oxmlSchema = New MSXML2.XMLSchemaCache40
    oxmlSchema.Add "", frmFileLoc.SchemaLocation & "\" & gstrSchemaName
    
    'Create an XML DOMDocument object.
    Set oxmlValidateDoc = New MSXML2.DOMDocument40
    
    'Assign the schema cache to the schemas collection.
    Set oxmlValidateDoc.schemas = oxmlSchema
    
    oxmlValidateDoc.async = False
    'Load the xml file as the DOM document.
    oxmlValidateDoc.Load MyXML_Filename
    
    Screen.MousePointer = vbNormal
    
    'Return validation results in message to the user.
    If oxmlValidateDoc.parseError.errorCode <> 0 Then
        If oxmlValidateDoc.parseError.errorCode = -2146697210 Then
            Err.Raise 1004
        Else
            ' Remove tabs from the text
            strText = Replace(oxmlValidateDoc.parseError.srcText, Chr$(9), "")
            frmValidate.lblResults.Alignment = vbLeftJustify
            frmValidate.lblResults.Caption = _
                    "Error: " & oxmlValidateDoc.parseError.reason _
                    & vbCrLf _
                    & "Found in line number " & oxmlValidateDoc.parseError.Line _
                    & "  line position " & oxmlValidateDoc.parseError.linepos & "." _
                    & vbCrLf & vbCrLf _
                    & strText _
                    & vbCrLf & vbCrLf _
                    & "(Other errors may be present.)"
            frmValidate.imgSad.Visible = True
            frmValidate.imgHappy.Visible = False
            frmValidate.Show vbModal
            frmMain.sbarStatus.Panels(1).Text = "Knowledge base validation failed"
        End If
    Else
        frmValidate.lblResults.Alignment = vbCenter
        frmValidate.lblResults.Caption = vbCrLf & vbCrLf _
                                       & "Knowledge base validation passed"
        frmValidate.imgSad.Visible = False
        frmValidate.imgHappy.Visible = True
        frmValidate.Show vbModal
        frmMain.sbarStatus.Panels(1).Text = "Knowledge base validation passed"
    End If
    
    Set oxmlSchema = Nothing
    Set oxmlValidateDoc = Nothing
 
    Exit Sub
    
ErrorRoutine:
 
    If Err.Number = 1004 Then
        MsgBox ResolveResString(resMissingTempFile), _
               vbExclamation + vbOKOnly, _
               ResolveResString(resErrorTitle, "|1", "Validation")
    Else
        DisplayError "ValidateXML"
    End If
   
End Sub

[danjevans]

Thanks for the response. I should have made myself clearer - I have a piece of code similar to that which you have posted; however I would like to extend it so that as well as displaying the piece of XML that has broken the Schema, I would like to display the Schema rule that it has broken.

I had assumed that the IXMLDOMNode.definition property would be ideal for this, acting as a pointer to the definition of the node in the Schema but I cannot seem to get it to work. In fact, even with XML that does match the Schema perfectly, the .definition property is always Nothing.

Any thoughts?

Thanks again,

[MartinLiss]

I've never tried to do that. Does this help at all?

[danjevans]

That page is similar to the one I found first whilst searching the MSDN. It makes it look so simple that I must be doing something wrong. Perhaps I am not hooking the Schema up to the XML object properly. I am using the technique that you listed above though and I've got the impression that this is the standard way of doing it.

Taken straight from the MSDN:
"Returns the XML-Data Schema ElementType for a given ELEMENT node. For example, given the element <myelement>, the definition method returns the node <ElementType name="myelement"> in the specified external schema. Returns Null when a DTD is used or when no schema is present."

I have an element node called <moon> and a Schema rule <Element name="moon"> and it still doesn't work. Does this mean that I MUST use the <ElementType> elements, which means I MUST use XDR Schemas (which my colleague is eager to tell me are a pile of ...)?

I'm beginning to suspect that this is simply one of those things that Cannot Be Done.

Thanks,

[danjevans]

Having just tried the same example using XDR instead of normal Schema's, the .definition property worked. I can only assume then that this property is only usable when using Microsofts XDR Schemas. Dead end

Can anyone think of any other way to find out which Schema rule has been broken by a particular XML element?

Thanks,