Can't cause MSXML 6 XSD validation error

Question

Hi folks,

VBA in Excel 2007, MSXML 6 - I'm trying to test that validation against an XSD I developed will fail if there are problems in documents associated with the schema.  I've been able to trigger validation errors against this schema using the Eclipse (Helios) XML tools, but I can't seem to cause MSXML 6 validation to fail unless it's something like basic well-formedness of the data document.  The schema document itself loads and validates without problems in MSXML 6.  I've tried 1) setting parseOnLoad true for the data document, 2)doing a manual validate() on the data document, and also adding the schema to a schemaCache and validating against that.  None of them will trip, again, unless it's a basic well-formedness problem.

It's been a while since I've had to do this, and I'm guessing I'm somehow not getting the namespaces wired correctly.  Would appreciate it if someone could let me know if the cause of the problem jumps out at them.

Here's the test code:

Sub checkSchema()
    Dim vMyErr As Variant
    
    Dim oXSDDoc As DOMDocument60
    Set oXSDDoc = New DOMDocument60
    oXSDDoc.async = False
    
    'Load XML Schema from a file
    oXSDDoc.validateOnParse = True
    oXSDDoc.Load (ThisWorkbook.Path & "\PSTTLTD2.xsd")
    If oXSDDoc.parseError.ErrorCode <> 0 Then
        Set vMyErr = oXSDDoc.parseError
        MsgBox "XML parsing error " + vMyErr.reason
    End If
    
    oXSDDoc.Validate
    If oXSDDoc.parseError.ErrorCode <> 0 Then
        Set vMyErr = oXSDDoc.parseError
        MsgBox "XML parsing error " + vMyErr.reason
    End If
    'Load XML document from a file
    Dim oSourceDoc As DOMDocument60
    Set oSourceDoc = New DOMDocument60
    oSourceDoc.async = False
    
    oSourceDoc.validateOnParse = True
    oSourceDoc.Load (ThisWorkbook.Path & "\XMLFinalSchemaTestDoc.xml")
    If oSourceDoc.parseError.ErrorCode <> 0 Then
        Set vMyErr = oSourceDoc.parseError
        MsgBox "XML parsing error " + vMyErr.reason
    End If
    oSourceDoc.Validate
    If oSourceDoc.parseError.ErrorCode <> 0 Then
        Set vMyErr = oSourceDoc.parseError
        MsgBox "XML parsing error " + vMyErr.reason
    End If
    
    'Validate with Schema Cache
    'Reload schema into cache.
    Set oXSDDoc = New DOMDocument60
    oXSDDoc.async = False
    oXSDDoc.Load (ThisWorkbook.Path & "\PSTTLTD2.xsd")
    Set oSchemaCache = New XMLSchemaCache60
    oSchemaCache.Add "urn:histogramList", oXSDDoc
    
    Set oSourceDoc.Schemas = oSchemaCache
    oSourceDoc.Validate
    If oSourceDoc.parseError.ErrorCode <> 0 Then
        Set vMyErr = oSourceDoc.parseError
        MsgBox "XML parsing error " + vMyErr.reason
    End If
End Sub

Here's the schema:

<?xml version="1.0" encoding="UTF-8"?>
<xs:schema targetNamespace="urn:histogramList"
      xmlns:xs="http://www.w3.org/2001/XMLSchema"
      xmlns:hL="urn:histogramList"
      elementFormDefault="qualified">
    <xs:element name="HistogramList">
       <xs:complexType>
          <xs:sequence>
             <xs:element name="Histogram" minOccurs="1" maxOccurs="unbounded">
                <xs:complexType>
                   <xs:sequence>
                     <xs:element name="DataRecord" minOccurs="1" maxOccurs="unbounded">
                        <xs:complexType>
                           <xs:sequence>
                               <xs:element name="Start" type="xs:integer" minOccurs="1" maxOccurs="1"/>
                               <xs:element name="Stop" type="xs:integer" minOccurs="1" maxOccurs="1"/>
                               <xs:element name="NumberOf" type="xs:integer" minOccurs="1" maxOccurs="1"/>
                            </xs:sequence>
                        </xs:complexType>
                     </xs:element>
                  </xs:sequence>
                  <xs:attribute name="ResourceName" use="required">
                     <xs:simpleType>
                        <xs:restriction base="xs:string">
                           <xs:pattern value="([a-zA-Z]([a-zA-Z0-9]|_|-)*){1}(\.([a-zA-Z]([a-zA-Z0-9]|_|-)*){1})*"/>
                        </xs:restriction>
                     </xs:simpleType>
                  </xs:attribute>
                  <xs:attribute name="HistogramType" type="xs:NMTOKENS" use="required"/>
               </xs:complexType>
            </xs:element>
          </xs:sequence>
       </xs:complexType>
    </xs:element>
 </xs:schema>

Here's a snippet of the XML document that I can't get to fail validation in MSXML - note that there is a missing required attribute on the <Histogram> element, and the first <DataRecord> element is actually misnamed "xDataRecord":

<?xml version="1.0"?>
<HistogramList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:histogramList PSTTLTD2.xsd"
xmlns="urn:histogramList">
	<Histogram  HistogramType="Net Usage">
		<xDataRecord><Start>7632000</Start><Stop>7660800</Stop><NumberOf>0</NumberOf></xDataRecord>
		<DataRecord><Start>7660800</Start><Stop>7689600</Stop><NumberOf>0</NumberOf></DataRecord>
		<DataRecord><Start>7689600</Start><Stop>7718400</Stop><NumberOf>0</NumberOf></DataRecord>
		<DataRecord><Start>7718400</Start><Stop>7747200</Stop><NumberOf>-6</NumberOf></DataRecord>
 

The XSD file is co-located with both the spreadsheet containing the VBA code, and the XML data document, so, as near as I can tell, the filename without a path should be valid (in any event, nothing complains that it can't locate the XSD, and the same simple location format reference also works in Eclipse when the XSD is in the same workspace).  However, note that I also tried a file reference in the following (example) format for the schema location:

urn:MyData file://C://Documents and Settings//All Users//Application Data//My Application//MyData.xsd

The longer format didn't seem to make any difference.)

Thanks for any help!

Answer 1

When I used MSXML 6 to perform schema validation then I simply added the schema to a schema collection, set that as the schemas property and validated while loading the document; here is a sample (with VBScript but of course the API to use is the same with VBA and early binding):

Dim xmlDoc, schemaCache

Set xmlDoc = CreateObject("Msxml2.DOMDocument.6.0")

Set schemaCache = CreateObject("Msxml2.XMLSchemaCache.6.0")
schemaCache.add "urn:histogramList", "test2012073101.xsd"

xmlDoc.schemas = schemaCache

xmlDoc.validateOnParse = True
xmlDoc.setProperty "MultipleErrorMessages", True

If xmlDoc.load("test2012073101.xml") then
  WScript.Echo "Document is well-formed and valid."
Else
  For Each pErr In xmlDoc.parseError.allErrors
    WScript.Echo "Error " & pErr.reason & " for " & pErr.errorXPath
  Next
End If

Now with the input XML being

<?xml version="1.0"?>
<HistogramList xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="urn:histogramList test2012073101.xsd"
xmlns="urn:histogramList">
	<Histogram  HistogramType="Net Usage">
		<xDataRecord><Start>7632000</Start><Stop>7660800</Stop><NumberOf>0</NumberOf></xDataRecord>
		<DataRecord><Start>7660800</Start><Stop>7689600</Stop><NumberOf>0</NumberOf></DataRecord>
		<DataRecord><Start>7689600</Start><Stop>7718400</Stop><NumberOf>0</NumberOf></DataRecord>
		<DataRecord><Start>7718400</Start><Stop>7747200</Stop><NumberOf>-6</NumberOf></DataRecord>
  </Histogram>
</HistogramList>

and the schema being as you posted I get the following error messages as the output:

Error Erforderliches Attribut 'ResourceName' fehlt.
 for /*[local-name()="HistogramList" and namespace-uri()="urn:histogramList"]/*[local-name()="Histogram" and namespace-u
ri()="urn:histogramList"][1]
Error Der Inhalt des Elements '{urn:histogramList}xDataRecord' ist gemäß dem Inhaltsmodell des übergeordneten Elements '
{urn:histogramList}Histogram' nicht gültig.
Erwartet: {urn:histogramList}DataRecord.
 for /*[local-name()="HistogramList" and namespace-uri()="urn:histogramList"]/*[local-name()="Histogram" and namespace-u
ri()="urn:histogramList"][1]/*[local-name()="xDataRecord" and namespace-uri()="urn:histogramList"][1]

Sorry, I am on a German version of Windows here so the messages MSXML outputs are German but it correctly complaints about the missing attribute and the incorrect child element.

If you don't want to load the scheme explicitly then I think you can also do

Dim xmlDoc, schemaCache

Set xmlDoc = CreateObject("Msxml2.DOMDocument.6.0")

'Set schemaCache = CreateObject("Msxml2.XMLSchemaCache.6.0")
'schemaCache.add "urn:histogramList", "test2012073101.xsd"

'xmlDoc.schemas = schemaCache

xmlDoc.validateOnParse = True
xmlDoc.resolveExternals = True
xmlDoc.setProperty "MultipleErrorMessages", True

If xmlDoc.load("test2012073101.xml") then
  WScript.Echo "Document is well-formed and valid."
Else
  For Each pErr In xmlDoc.parseError.allErrors
    WScript.Echo "Error " & pErr.reason & " for " & pErr.errorXPath
  Next
End If

That way the schema is loaded from the location given in the schemaLocation attribute.

---

MVP Data Platform Development My blog

Answer 2

Thanks, Martin.

I've got it working in VBA if I follow your steps in those precise sequences.