C# – Possible to validate xml against xsd using code at runtime

cschemaxmlxml-validationxsd

I have xml files that I read in at runtime, is is possible to validate the xml against an xsd file at runtime? using c#

Best Answer

Try this:

public void ValidateXmlDocument(
    XmlReader documentToValidate, string schemaPath)
{
    XmlSchema schema;
    using (var schemaReader = XmlReader.Create(schemaPath))
    {
        schema = XmlSchema.Read(schemaReader, ValidationEventHandler);
    }

    var schemas = new XmlSchemaSet();
    schemas.Add(schema);

    var settings = new XmlReaderSettings();
    settings.ValidationType = ValidationType.Schema;
    settings.Schemas = schemas;
    settings.ValidationFlags =
        XmlSchemaValidationFlags.ProcessIdentityConstraints |
        XmlSchemaValidationFlags.ReportValidationWarnings;
    settings.ValidationEventHandler += ValidationEventHandler;

    using (var validationReader = XmlReader.Create(documentToValidate, settings))
    {
        while (validationReader.Read())
        {
        }
    }
}

private static void ValidationEventHandler(
    object sender, ValidationEventArgs args)
{
    if (args.Severity == XmlSeverityType.Error)
    {
        throw args.Exception;
    }

    Debug.WriteLine(args.Message);
}

Related Solutions

Java – What’s the best way to validate an XML file against an XSD file

The Java runtime library supports validation. Last time I checked this was the Apache Xerces parser under the covers. You should probably use a javax.xml.validation.Validator.

import javax.xml.XMLConstants;
import javax.xml.transform.Source;
import javax.xml.transform.stream.StreamSource;
import javax.xml.validation.*;
import java.net.URL;
import org.xml.sax.SAXException;
//import java.io.File; // if you use File
import java.io.IOException;
...
URL schemaFile = new URL("http://host:port/filename.xsd");
// webapp example xsd: 
// URL schemaFile = new URL("http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd");
// local file example:
// File schemaFile = new File("/location/to/localfile.xsd"); // etc.
Source xmlFile = new StreamSource(new File("web.xml"));
SchemaFactory schemaFactory = SchemaFactory
    .newInstance(XMLConstants.W3C_XML_SCHEMA_NS_URI);
try {
  Schema schema = schemaFactory.newSchema(schemaFile);
  Validator validator = schema.newValidator();
  validator.validate(xmlFile);
  System.out.println(xmlFile.getSystemId() + " is valid");
} catch (SAXException e) {
  System.out.println(xmlFile.getSystemId() + " is NOT valid reason:" + e);
} catch (IOException e) {}

The schema factory constant is the string http://www.w3.org/2001/XMLSchema which defines XSDs. The above code validates a WAR deployment descriptor against the URL http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd but you could just as easily validate against a local file.

You should not use the DOMParser to validate a document (unless your goal is to create a document object model anyway). This will start creating DOM objects as it parses the document - wasteful if you aren't going to use them.

C# – Case insensitive ‘Contains(string)’

You could use the String.IndexOf Method and pass StringComparison.OrdinalIgnoreCase as the type of search to use:

string title = "STRING";
bool contains = title.IndexOf("string", StringComparison.OrdinalIgnoreCase) >= 0;

Even better is defining a new extension method for string:

public static class StringExtensions
{
    public static bool Contains(this string source, string toCheck, StringComparison comp)
    {
        return source?.IndexOf(toCheck, comp) >= 0;
    }
}

Note, that null propagation ?. is available since C# 6.0 (VS 2015), for older versions use

if (source == null) return false;
return source.IndexOf(toCheck, comp) >= 0;

USAGE:

string title = "STRING";
bool contains = title.Contains("string", StringComparison.OrdinalIgnoreCase);

Best Answer

Related Solutions

Java – What’s the best way to validate an XML file against an XSD file

C# – Case insensitive ‘Contains(string)’

Related Topic