PolicyConversionContext.GetBindingAssertions Method

Definition

Namespace:

System.ServiceModel.Description

Assembly:

System.ServiceModel.dll

Gets a collection of policy assertions from metadata.

public:
 abstract System::ServiceModel::Description::PolicyAssertionCollection ^ GetBindingAssertions();

public abstract System.ServiceModel.Description.PolicyAssertionCollection GetBindingAssertions ();

abstract member GetBindingAssertions : unit -> System.ServiceModel.Description.PolicyAssertionCollection

Public MustOverride Function GetBindingAssertions () As PolicyAssertionCollection

Returns

PolicyAssertionCollection

An ICollection<T> of type XmlElement that contains binding policy assertions.

Examples

The following code example shows an implementation of the ImportPolicy method that writes all policy assertions to the console. The code comments describe how to locate a specific custom policy assertion, create and insert an implementing binding element, and remove the assertion from the collection.

public void ImportPolicy(MetadataImporter importer,
    PolicyConversionContext context)
{
    Console.WriteLine("The custom policy importer has been called.");
    foreach (XmlElement assertion in context.GetBindingAssertions())
    {
        Console.WriteLine(assertion.NamespaceURI + " : " + assertion.Name);
        // locate a particular assertion by Name and NamespaceURI
        XmlElement customAssertion = context.GetBindingAssertions().Find(name1, ns1);
        if (customAssertion != null)
        {
          // Found assertion; remove from collection.
          context.GetBindingAssertions().Remove(customAssertion);
          Console.WriteLine(
            "Removed our custom assertion from the imported "
            + "assertions collection and inserting our custom binding element."
          );
            // Here if you find the custom policy assertion that you are looking for,
            // add the custom binding element that handles the functionality that the policy indicates.
            // Attach it to the PolicyConversionContext.BindingElements collection.
            // For example, if the custom policy had a "speed" attribute value:
            /*
              string speed
                = customAssertion.GetAttribute(SpeedBindingElement.name2, SpeedBindingElement.ns2);
              SpeedBindingElement e = new SpeedBindingElement(speed);
              context.BindingElements.Add(e);
            */
        }

        // write assertion name in red.
        Console.ForegroundColor = ConsoleColor.Red;
        Console.WriteLine(assertion.NamespaceURI + " : " + assertion.Name);

        //write contents in gray.
        Console.WriteLine(assertion.OuterXml);
        Console.ForegroundColor = ConsoleColor.Gray;
    }
}

The following code example shows how to register IPolicyImportExtension implementations using the <policyImporters> configuration section.

<configuration>
  <system.serviceModel>
    <client>
      <metadata>
        <policyImporters>
          <extension type="CustomPolicyImporter, assembly"/>
        </policyImporters>
      </metadata>
    </client>
  </system.serviceModel>
</configuration>

The following code example demonstrates how a custom binding element can implement IPolicyExportExtension to attach a custom policy assertion to the binding assertions.

public class MyBindingElement : BindingElement, IPolicyExportExtension
{
// BindingElement implementation . . .

    public void ExportPolicy(
     MetadataExporter exporter, PolicyConversionContext context)
    {
        XmlDocument xmlDoc = new XmlDocument();
        XmlElement xmlElement =
               xmlDoc.CreateElement("MyPolicyAssertion");
        context.GetBindingAssertions().Add(xmlElement);
    }

    // Note: All custom binding elements must return a deep clone
    // to enable the run time to support multiple bindings using the
    // same custom binding.
    public override BindingElement Clone()
    {
        // this is just a placeholder
        return null;
    }

    // Call the inner property.
    public override T GetProperty<T>(BindingContext context)
    {
        return context.GetInnerProperty<T>();
    }
}

public class Program {
    public static void Main(string[] args) {
        EndpointAddress address =
            new EndpointAddress("http://localhost/metadata");
        CustomBinding customBinding =
            new CustomBinding(new BasicHttpBinding());
        customBinding.Elements.Add(new MyBindingElement());
        ContractDescription contract =
            ContractDescription.GetContract(typeof(MyContract));
        ServiceEndpoint endpoint =
            new ServiceEndpoint(contract, customBinding, address);
        MetadataExporter exporter = new WsdlExporter();
        exporter.ExportEndpoint(endpoint);
    }
}

Remarks

The collection returned from GetBindingAssertions is not a copy. You can add and remove assertions as necessary.