Catching Line Numbers with XmlDocument.Validate()

  • Thread starter Thread starter Guest
  • Start date Start date
G

Guest

I have this code:

XmlDocument x = new XmlDocument();
x.Schemas.Add(
null //use the targetnamespace stored in the schema file
, ExtendedTreeViewSchema //URL of schema file.
);

x.LoadXml(XmlSource);

x.Validate(new ValidationEventHandler(Handler));

The event handler looks like this:

private static void Handler(object sender, ValidationEventArgs e)
{

if (e.Severity == XmlSeverityType.Error || e.Severity ==
XmlSeverityType.Warning)
System.Diagnostics.Trace.WriteLine(
String.Format("Line: {0}, Position: {1} \"{2}\"",
e.Exception.LineNumber, e.Exception.LinePosition,
e.Exception.Message));

}

In VS2005 IDE I can take an XML document and purposely invalidate a couple
of lines according to the schema specification. Having done so, I see the
following messages in the VS2005 IDE:

Warning 1 The 'columnValue' element is invalid - The value 'AUD'' is invalid
according to its datatype
VS also tells me this warning occurred on Line 31 at Column 30

Warning 2 The 'columnValue' element is invalid - The value 'CRC*'' is
invalid according to its datatype
VS also tells me that this warning occurred on Line 41 at column 31.

Both Warnings and Lines/Column numbers are what I expect based on the errors
I purposely made in the file.


When I run the code using the same XML file, I get the same messages but
the Line and Column numbers are always 0:

Line: 0, Position: 0 "The 'columnValue' element is invalid - The value
'AUD'' is invalid according to its datatype

Line: 0, Position: 0 "The 'columnValue' element is invalid - The value
'CRC*'' is invalid according to its datatype

What am I doing wrong?
 
Thus wrote Brian,
I have this code:

XmlDocument x = new XmlDocument();
x.Schemas.Add(
null //use the targetnamespace stored in the schema file
, ExtendedTreeViewSchema //URL of schema file.
);
x.LoadXml(XmlSource);

x.Validate(new ValidationEventHandler(Handler));

The event handler looks like this:

private static void Handler(object sender, ValidationEventArgs e)
{
if (e.Severity == XmlSeverityType.Error || e.Severity ==
XmlSeverityType.Warning)
System.Diagnostics.Trace.WriteLine(
String.Format("Line: {0}, Position: {1} \"{2}\"",
e.Exception.LineNumber, e.Exception.LinePosition,
e.Exception.Message));
}

In VS2005 IDE I can take an XML document and purposely invalidate a
couple of lines according to the schema specification. Having done
so, I see the following messages in the VS2005 IDE:

Warning 1 The 'columnValue' element is invalid - The value 'AUD'' is
invalid
according to its datatype
VS also tells me this warning occurred on Line 31 at Column 30
Warning 2 The 'columnValue' element is invalid - The value 'CRC*'' is
invalid according to its datatype VS also tells me that this warning
occurred on Line 41 at column 31.

Both Warnings and Lines/Column numbers are what I expect based on the
errors I purposely made in the file.

When I run the code using the same XML file, I get the same messages
but the Line and Column numbers are always 0:

Line: 0, Position: 0 "The 'columnValue' element is invalid - The value
'AUD'' is invalid according to its datatype

Line: 0, Position: 0 "The 'columnValue' element is invalid - The value
'CRC*'' is invalid according to its datatype

What am I doing wrong?
Click to expand...

Validation warnings are disabled by default. What you need to do is create
an XmlReaderSettings object and enable warnings through that object.

Unfortunately, there seems to be no way to pass your own XmlReaderSettings
object to XmlDocument.Validate(). Instead, you can use a validating XmlReader
and an XmlNodeReader to validate an existing XmlDocument like this:

// Configure validation options
XmlReaderSettings settings = new XmlReaderSettings();
settings.CloseInput = true;
settings.ValidationEventHandler += OnValidationEvent; // Your callback...
settings.ValidationType = ValidationType.Schema;
settings.ValidationFlags =
XmlSchemaValidationFlags.ReportValidationWarnings |
XmlSchemaValidationFlags.ProcessIdentityConstraints |
XmlSchemaValidationFlags.ProcessInlineSchema |
XmlSchemaValidationFlags.ProcessSchemaLocation;

// Wrap document in an XmlNodeReader and run validation on top of that
XmlNodeReader nodeReader = new XmlNodeReader(xmlDocument);
using(XmlReader validatingReader = XmlReader.Create(nodeReader, settings)) {
while(validatingReader.Read()) { /* just loop through document */ }
}

Cheers,
 
Still getting Line number zero, position zero in the Handler. Here is the
relevant code:

XmlDocument x = new XmlDocument();
x.LoadXml(XmlSource);

XmlReaderSettings settings = new XmlReaderSettings();
settings.CloseInput = true;
settings.ValidationEventHandler += Handler;

settings.ValidationType = ValidationType.Schema;
settings.Schemas.Add(null, ExtendedTreeViewSchema);
settings.ValidationFlags =
XmlSchemaValidationFlags.ReportValidationWarnings |
XmlSchemaValidationFlags.ProcessIdentityConstraints |
XmlSchemaValidationFlags.ProcessInlineSchema |
XmlSchemaValidationFlags.ProcessSchemaLocation ;


XmlNodeReader nodeReader = new XmlNodeReader(x);
using (XmlReader validatingReader = XmlReader.Create(nodeReader, settings))
{
while (validatingReader.Read()) { /* just loop through document */ }
}

And the handler:

private static void Handler(object sender, ValidationEventArgs e)
{

if (e.Severity == XmlSeverityType.Error || e.Severity ==
XmlSeverityType.Warning)
System.Diagnostics.Trace.WriteLine(
String.Format("Line: {0}, Position: {1} \"{2}\"",
e.Exception.LineNumber, e.Exception.LinePosition,
e.Exception.Message));

}

As before, I see the expected error messages but not the line numbers.
 
It works when I do away with the XmlDocument and replace XmlNodeReader with
StringReader, i.e.,

StringReader r = new StringReader(XmlSource);

using (XmlReader validatingReader = XmlReader.Create(r, settings)) {
while (validatingReader.Read()) { /* just loop through document */ }
}
 
Back
Top