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How to: Export Custom WSDL

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This topic explains how to export custom WSDL information. To do this we will define a new code attribute called WsdlDocumentationAttribute that will add custom information into the WSDL generated by the service.

To export custom WSDL information

  1. Implement the IWsdlExportExtension interface. This interface can be implemented on a class that implements any of the following interfaces: IOperationBehavior, IContractBehavior, or IEndpointBehavior. It can also be implemented on a class derived from BindingElement. This sample implements IWsdlExportExtension on an attribute class that implements IContractBehavior.

  2. IWsdlExportExtension defines two methods ExportEndpoint(WsdlExporter, WsdlEndpointConversionContext) and ExportContract(WsdlExporter, WsdlContractConversionContext). These methods allow you to modify or add (or both modify and add) additional information into the WsdlContractConversionContext. This sample, in the ExportContract(WsdlExporter, WsdlContractConversionContext) method, retrieves a collection of OperationDescription objects and then iterates through the collection checking for a WsdlDocumentationAttribute. If one is found, the text associated with the attribute is extracted, a summary element is generated, and the summary element is added into the DocumentationElement of the operation.

    public void ExportContract(WsdlExporter exporter, WsdlContractConversionContext context)
{
    Console.WriteLine("Inside ExportContract");
    if (context.Contract != null)
    {
        // Set the document element; if this is not done first, there is no XmlElement in the
        // DocumentElement property.
        context.WsdlPortType.Documentation = string.Empty;
        // Contract comments.
        XmlDocument owner = context.WsdlPortType.DocumentationElement.OwnerDocument;
        XmlElement summaryElement = Formatter.CreateSummaryElement(owner, this.Text);
        context.WsdlPortType.DocumentationElement.AppendChild(summaryElement);

        foreach (OperationDescription op in context.Contract.Operations)
        {
            Operation operation = context.GetOperation(op);
            object[] opAttrs = op.SyncMethod.GetCustomAttributes(typeof(WsdlDocumentationAttribute), false);
            if (opAttrs.Length == 1)
            {
                string opComment = ((WsdlDocumentationAttribute)opAttrs[0]).Text;

                // This.Text returns the string for the operation-level attributes.
                // Set the doc element; if this is not done first, there is no XmlElement in the
                // DocumentElement property.
                operation.Documentation = String.Empty;

                XmlDocument opOwner = operation.DocumentationElement.OwnerDocument;
                XmlElement newSummaryElement = Formatter.CreateSummaryElement(opOwner, opComment);
                operation.DocumentationElement.AppendChild(newSummaryElement);
            }
        }
    }
}

Example

The following code example shows the full implementation of the WsdlDocumentationAttribute class.

public class WsdlDocumentationAttribute : Attribute, IContractBehavior, IWsdlExportExtension
{
string text;
       XmlElement customWsdlDocElement = null;
public WsdlDocumentationAttribute(string text)
{ this.text = text;}

       public WsdlDocumentationAttribute(XmlElement wsdlDocElement)
        { this.customWsdlDocElement = wsdlDocElement; }

        public XmlElement WsdlDocElement
        {
            get { return this.customWsdlDocElement; }
            set { this.customWsdlDocElement = value; }
        }
       public string Text
{
get { return this.text; }
set { this.text = value; }
}

     public void ExportContract(WsdlExporter exporter, WsdlContractConversionContext context)
{
          Console.WriteLine("Inside ExportContract");
if (context.Contract != null)
{
                // Set the document element; if this is not done first, there is no XmlElement in the
                // DocumentElement property.
                context.WsdlPortType.Documentation = string.Empty;
                // Contract comments.
                XmlDocument owner = context.WsdlPortType.DocumentationElement.OwnerDocument;
                XmlElement summaryElement = Formatter.CreateSummaryElement(owner, this.Text);
                context.WsdlPortType.DocumentationElement.AppendChild(summaryElement);

                foreach (OperationDescription op in context.Contract.Operations)
                {
                    Operation operation = context.GetOperation(op);
                    object[] opAttrs = op.SyncMethod.GetCustomAttributes(typeof(WsdlDocumentationAttribute), false);
                    if (opAttrs.Length == 1)
                    {
                        string opComment = ((WsdlDocumentationAttribute)opAttrs[0]).Text;

                        // This.Text returns the string for the operation-level attributes.
                        // Set the document element; if this is not done first, there is no XmlElement in the
                        // DocumentElement property.
                        operation.Documentation = String.Empty;

                        XmlDocument opOwner = operation.DocumentationElement.OwnerDocument;
                        XmlElement newSummaryElement = Formatter.CreateSummaryElement(opOwner, opComment);
                        operation.DocumentationElement.AppendChild(newSummaryElement);
                    }
                }
            }
        }

public void ExportEndpoint(WsdlExporter exporter, WsdlEndpointConversionContext context)
        {
            Console.WriteLine("ExportEndpoint called.");
        }

        public void AddBindingParameters(ContractDescription description, ServiceEndpoint endpoint, BindingParameterCollection parameters)
        { return; }

        public void ApplyClientBehavior(ContractDescription description, ServiceEndpoint endpoint, ClientRuntime client)
        { return; }

        public void ApplyDispatchBehavior(ContractDescription description, ServiceEndpoint endpoint, DispatchRuntime dispatch)
        { return; }

        public void Validate(ContractDescription description, ServiceEndpoint endpoint) { return; }
    }

  public class Formatter
  {

#region Utility Functions

    public static XmlElement CreateSummaryElement(XmlDocument owningDoc, string text)
    {
      XmlElement summaryElement = owningDoc.CreateElement("summary");
      summaryElement.InnerText = text;
      return summaryElement;
    }

public static CodeCommentStatementCollection FormatComments(string text)
{
      /*
       * Note that in Visual C# the XML comment format absorbs a
       * documentation element with a line break in the middle. This sample
       * could take an XmlElement and create code comments in which
       * the element never had a line break in it.
      */

      CodeCommentStatementCollection collection = new CodeCommentStatementCollection();
collection.Add(new CodeCommentStatement("From WsdlDocumentation:", true));
collection.Add(new CodeCommentStatement(String.Empty, true));

foreach (string line in WordWrap(text, 80))
{
collection.Add(new CodeCommentStatement(line, true));
}

collection.Add(new CodeCommentStatement(String.Empty, true));
return collection;
}

public static Collection<string> WordWrap(string text, int columnWidth)
{
Collection<string> lines = new Collection<string>();
System.Text.StringBuilder builder = new System.Text.StringBuilder();

string[] words = text.Split(' ');
foreach (string word in words)
{
if ((builder.Length > 0) && ((builder.Length + word.Length + 1) > columnWidth))
{
lines.Add(builder.ToString());
builder = new System.Text.StringBuilder();
}
builder.Append(word);
builder.Append(' ');
}
lines.Add(builder.ToString());

return lines;
}

#endregion

    public static XmlElement CreateReturnsElement(XmlDocument owner, string p)
    {
      XmlElement returnsElement = owner.CreateElement("returns");
      returnsElement.InnerText = p;
      return returnsElement;
    }
  }

See also