XDR Validation with XmlSchemaCollection
If the XML-Data Reduced (XDR) schema you are validating against is stored in the XmlSchemaCollection, it is associated with the namespace URI specified when the schema was added to the collection. XmlValidatingReader maps the namespace URI in the XML document to the schema that corresponds to that URI in the collection.
Important
The XmlSchemaCollection class is now obsolete and has been replaced with the XmlSchemaSet class. For more information about the XmlSchemaSet class see, XmlSchemaSet for Schema Compilation.
For example, if the root element of the XML document is <bookstore xmlns="urn:newbooks-schema">
, when the schema is added to the XmlSchemaCollection it references the same namespace, as follows:
xsc.Add("urn:newbooks-schema", "newbooks.xdr")
xsc.Add("urn:newbooks-schema", "newbooks.xdr");
The following code example creates an XmlValidatingReader that takes an XmlTextReader and adds an XDR schema, HeadCount.xdr, to the XmlSchemaCollection:
Imports System.IO
Imports System.Xml
Imports System.Xml.Schema
Namespace ValidationSample
Class Sample
Public Shared Sub Main()
Dim tr As New XmlTextReader("HeadCount.xml")
Dim vr As New XmlValidatingReader(tr)
vr.Schemas.Add("xdrHeadCount", "HeadCount.xdr")
vr.ValidationType = ValidationType.XDR
AddHandler vr.ValidationEventHandler, AddressOf ValidationHandler
While vr.Read()
PrintTypeInfo(vr)
If vr.NodeType = XmlNodeType.Element Then
While vr.MoveToNextAttribute()
PrintTypeInfo(vr)
End While
End If
End While
Console.WriteLine("Validation finished")
End Sub
Public Shared Sub PrintTypeInfo(vr As XmlValidatingReader)
If vr.SchemaType IsNot Nothing Then
If TypeOf vr.SchemaType Is XmlSchemaDatatype Or TypeOf vr.SchemaType Is XmlSchemaSimpleType Then
Dim value As Object = vr.ReadTypedValue()
Console.WriteLine($"{vr.NodeType}({vr.Name},{value.GetType().Name}):{value}")
End If
End If
End Sub
Public Shared Sub ValidationHandler(sender As Object, args As ValidationEventArgs)
Console.WriteLine("***Validation error")
Console.WriteLine($"Severity:{args.Severity}")
Console.WriteLine($"Message:{args.Message}")
End Sub
End Class
End Namespace
using System;
using System.IO;
using System.Xml;
using System.Xml.Schema;
namespace ValidationSample
{
class Sample
{
public static void Main()
{
var tr = new XmlTextReader("HeadCount.xml");
var vr = new XmlValidatingReader(tr);
vr.Schemas.Add("xdrHeadCount", "HeadCount.xdr");
vr.ValidationType = ValidationType.XDR;
vr.ValidationEventHandler += new ValidationEventHandler (ValidationHandler);
while(vr.Read())
{
PrintTypeInfo(vr);
if (vr.NodeType == XmlNodeType.Element)
{
while(vr.MoveToNextAttribute())
PrintTypeInfo(vr);
}
}
Console.WriteLine("Validation finished");
}
public static void PrintTypeInfo(XmlValidatingReader vr)
{
if (vr.SchemaType != null)
{
if(vr.SchemaType is XmlSchemaDatatype || vr.SchemaType is XmlSchemaSimpleType)
{
object value = vr.ReadTypedValue();
Console.WriteLine($"{vr.NodeType}({vr.Name},{value.GetType().Name}):{value}");
}
}
}
public static void ValidationHandler(object sender, ValidationEventArgs args)
{
Console.WriteLine("***Validation error");
Console.WriteLine($"\tSeverity:{args.Severity}");
Console.WriteLine($"\tMessage:{args.Message}");
}
}
}
The following outlines the contents of the input file, HeadCount.xml, to be validated:
<!--Load HeadCount.xdr in SchemaCollection for Validation-->
<HeadCount xmlns='xdrHeadCount'>
<Name>Waldo Pepper</Name>
<Name>Red Pepper</Name>
</HeadCount>
The following outlines the contents of the XDR schema file, HeadCount.xdr, to be validated against:
<Schema xmlns="urn:schemas-microsoft-com:xml-data" xmlns:dt="urn:schemas-microsoft-com:datatypes">
<ElementType name="Name" content="textOnly"/>
<AttributeType name="Bldg" default="2"/>
<ElementType name="HeadCount" content="eltOnly">
<element type="Name"/>
<attribute type="Bldg"/>
</ElementType>
</Schema>
See also
Feedback
https://aka.ms/ContentUserFeedback.
Coming soon: Throughout 2024 we will be phasing out GitHub Issues as the feedback mechanism for content and replacing it with a new feedback system. For more information see:Submit and view feedback for