I’m currently working on an XML File Explorer application, which I intend on highlighting XML files which do not conform to an XSD schema, as part of this I have created a class for containing the details of performing XSD validation against an XML document, which I thought I would share with you (although the XML File Explorer will be open source).
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml;
using System.Xml.Schema;
namespace KetoLibrary.Xml
{
public class XsdValidator
{
public List<XmlSchema> Schemas { get; set; }
public List<String> Errors { get; set; }
public List<String> Warnings { get; set; }
public XsdValidator()
{
Schemas = new List<XmlSchema>();
}
/// <summary>
/// Add a schema to be used during the validation of the XML document
/// </summary>
/// <param name="schemaFileLocation">The file path for the XSD schema file to be added for validation</param>
/// <returns>True if the schema file was successfully loaded, else false (if false, view Errors/Warnings for reason why)</returns>
public bool AddSchema(string schemaFileLocation)
{
if (String.IsNullOrEmpty(schemaFileLocation)) return false;
if (!File.Exists(schemaFileLocation)) return false;
// Reset the Error/Warning collections
Errors = new List<string>();
Warnings = new List<string>();
XmlSchema schema;
using (var fs = File.OpenRead(schemaFileLocation))
{
schema = XmlSchema.Read(fs, ValidationEventHandler);
}
var isValid = !Errors.Any() && !Warnings.Any();
if (isValid)
{
Schemas.Add(schema);
}
return isValid;
}
/// <summary>
/// Perform the XSD validation against the specified XML document
/// </summary>
/// <param name="xmlLocation">The full file path of the file to be validated</param>
/// <returns>True if the XML file conforms to the schemas, else false</returns>
public bool IsValid(string xmlLocation)
{
if (!File.Exists(xmlLocation))
{
throw new FileNotFoundException("The specified XML file does not exist", xmlLocation);
}
using (var xmlStream = File.OpenRead(xmlLocation))
{
return IsValid(xmlStream);
}
}
/// <summary>
/// Perform the XSD validation against the supplied XML stream
/// </summary>
/// <param name="xmlStream">The XML stream to be validated</param>
/// <returns>True is the XML stream conforms to the schemas, else false</returns>
private bool IsValid(Stream xmlStream)
{
// Reset the Error/Warning collections
Errors = new List<string>();
Warnings = new List<string>();
var settings = new XmlReaderSettings
{
ValidationType = ValidationType.Schema
};
settings.ValidationEventHandler += ValidationEventHandler;
foreach (var xmlSchema in Schemas)
{
settings.Schemas.Add(xmlSchema);
}
var xmlFile = XmlReader.Create(xmlStream, settings);
try
{
while (xmlFile.Read()) { }
}
catch (XmlException xex)
{
Errors.Add(xex.Message);
}
return !Errors.Any() && !Warnings.Any();
}
private void ValidationEventHandler(object sender, ValidationEventArgs e)
{
switch (e.Severity)
{
case XmlSeverityType.Error:
Errors.Add(e.Message);
break;
case XmlSeverityType.Warning:
Warnings.Add(e.Message);
break;
}
}
}
}
The code is pretty simple but I’m a fan of hiding away any complexities so that I don’t have to think about them when I’m working on a project. The usage for this class is pretty simple as well, requiring you pass in the XSD schemas and then call IsValid specifying the XML file to validate.
public void MultipleSchemas()
{
var validator = new XsdValidator();
validator.AddSchema(@"SchemaDoc1.xsd");
validator.AddSchema(@"SchemaDoc2.xsd");
var isValid = validator.IsValid(@"ValidXmlDoc1.xml");
}
Both the XsdValidator and the usage example are hosted on GitHub Gists so feel free to head over to here and do what you want.
