C# – how to find restriction values in a simple xsd element with c#

cxmlxsd

How can I retrieve these enumeration types on an xsd simpleType with c#? Here is a sample simple type?

<xs:simpleType name="PaymentType">
    <xs:restriction base="xs:string">
      <xs:enumeration value="Cash" />
      <xs:enumeration value="CreditCard" />
  </xs:restriction>
</xs:simpleType>

thank you

Best Answer

You could look at using the Schema Object Model (SOM) as in this code:

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Xml;
using System.Xml.Schema;

namespace Testing.Xml
{
    class Program
    {
        static void Main(string[] args)
        {
            // read the schema
            XmlSchema schema;
            using (var reader = new StreamReader(@"c:\path\to\schema.xsd"))
            {
                schema = XmlSchema.Read(reader, null);
            }

            // compile so that post-compilation information is available
            XmlSchemaSet schemaSet = new XmlSchemaSet();
            schemaSet.Add(schema);
            schemaSet.Compile();

            // update schema reference
            schema = schemaSet.Schemas().Cast<XmlSchema>().First();

            var simpleTypes = schema.SchemaTypes.Values.OfType<XmlSchemaSimpleType>()
                                               .Where(t => t.Content is XmlSchemaSimpleTypeRestriction);

            foreach (var simpleType in simpleTypes)
            {
                var restriction = (XmlSchemaSimpleTypeRestriction) simpleType.Content;
                var enumFacets = restriction.Facets.OfType<XmlSchemaEnumerationFacet>();

                if (enumFacets.Any())
                {
                    Console.WriteLine("" + simpleType.Name);
                    foreach (var facet in enumFacets)
                    {
                        Console.WriteLine(facet.Value);
                    }
                }
            }
        }
    }
}

This code only works for named simple types though - if you have elements or attributes that contain anonymous simple types then it gets a lot more complicated as you have to walk all the elements and attributes to find simple types that have restriction content with enumeration facets.

Related Solutions

C# – String representation of an Enum

Try type-safe-enum pattern.

public sealed class AuthenticationMethod {

    private readonly String name;
    private readonly int value;

    public static readonly AuthenticationMethod FORMS = new AuthenticationMethod (1, "FORMS");
    public static readonly AuthenticationMethod WINDOWSAUTHENTICATION = new AuthenticationMethod (2, "WINDOWS");
    public static readonly AuthenticationMethod SINGLESIGNON = new AuthenticationMethod (3, "SSN");        

    private AuthenticationMethod(int value, String name){
        this.name = name;
        this.value = value;
    }

    public override String ToString(){
        return name;
    }

}

Update Explicit (or implicit) type conversion can be done by

adding static field with mapping
```
private static readonly Dictionary<string, AuthenticationMethod> instance = new Dictionary<string,AuthenticationMethod>();
```
- n.b. In order that the initialisation of the the "enum member" fields doesn't throw a NullReferenceException when calling the instance constructor, be sure to put the Dictionary field before the "enum member" fields in your class. This is because static field initialisers are called in declaration order, and before the static constructor, creating the weird and necessary but confusing situation that the instance constructor can be called before all static fields have been initialised, and before the static constructor is called.
filling this mapping in instance constructor
```
instance[name] = this;
```

and adding user-defined type conversion operator

public static explicit operator AuthenticationMethod(string str)
{
    AuthenticationMethod result;
    if (instance.TryGetValue(str, out result))
        return result;
    else
        throw new InvalidCastException();
}

C# – How to detect the SimpleType in XSD file

If you are just trying to parse the schema then you should take a look at this code sample from the tutorial How Do I...Use the Xml Schema Object Model?. (I did notice that the restriction is not fully implemented -- it doesn't get the restriction base type or any facets.)

Applying to your code sample would give something like this:

    // Add the customer schema to a new XmlSchemaSet and compile it.
    // Any schema validation warnings and errors encountered reading or 
    // compiling the schema are handled by the ValidationEventHandler delegate.
    XmlSchemaSet schemaSet = new XmlSchemaSet();
    schemaSet.ValidationEventHandler += new ValidationEventHandler(ValidationCallback);
    schemaSet.Add("http://www.w3.org/2001/XMLSchema", "D:\\TMP\\test.xsd");
    schemaSet.Compile();

    // Retrieve the compiled XmlSchema object from the XmlSchemaSet
    // by iterating over the Schemas property.
    XmlSchema customerSchema = null;
    foreach (XmlSchema schema in schemaSet.Schemas())
    {
        customerSchema = schema;
    }

    // Iterate over all schema items
    foreach (object item in xmlSchema.Items)
    {
        if (item is XmlSchemaAttribute)
        {
        }
        else if (item is XmlSchemaComplexType)
        {
        }
        else if (item is XmlSchemaSimpleType)
        {
            XmlSchemaSimpleType simpleType = item as XmlSchemaSimpleType;
            Console.WriteLine("SimpleType found with name=" + simpleType.Name);
        }
        else if (item is XmlSchemaElement)
        {
        }
        else if (item is XmlSchemaAnnotation)
        {
        }
        else if (item is XmlSchemaAttributeGroup)
        {
        }
        else if (item is XmlSchemaNotation)
        {
        }
        else if (item is XmlSchemaGroup)
        {
        }
        else
        {
            Console.WriteLine("Not Implemented.");
        }
    }

Best Answer

Related Solutions

C# – String representation of an Enum

C# – How to detect the SimpleType in XSD file

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