Export (0) Print
Expand All

SoapExtension Class

The base class for SOAP extensions for XML Web services created using ASP.NET.

System.Object
  System.Web.Services.Protocols.SoapExtension

Namespace:  System.Web.Services.Protocols
Assembly:  System.Web.Services (in System.Web.Services.dll)

public abstract class SoapExtension

The SoapExtension type exposes the following members.

  NameDescription
Protected methodSoapExtensionInitializes a new instance of the SoapExtension class.
Top

  NameDescription
Public methodChainStreamWhen overridden in a derived class, allows a SOAP extension access to the memory buffer containing the SOAP request or response.
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetInitializer(Type)When overridden in a derived class, allows a SOAP extension to initialize data specific to a class implementing an XML Web service at a one time performance cost.
Public methodGetInitializer(LogicalMethodInfo, SoapExtensionAttribute)When overridden in a derived class, allows a SOAP extension to initialize data specific to an XML Web service method using an attribute applied to the XML Web service method at a one time performance cost.
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Public methodInitializeWhen overridden in a derived class, allows a SOAP extension to initialize itself using the data cached in the GetInitializer method.
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodProcessMessageWhen overridden in a derived class, allows a SOAP extension to receive a SoapMessage to process at each SoapMessageStage.
Public methodToStringReturns a string that represents the current object. (Inherited from Object.)
Top

ASP.NET allows a SOAP-related infrastructure to be built by means of an extensibility mechanism. The ASP.NET SOAP extension architecture revolves around an extension that can inspect or modify a message at specific stages in message processing on either the client or the server.

ASP.NET SOAP extensions derive from the SoapExtension class. The GetInitializer and Initialize methods provide alternative mechanisms for initializing the SOAP extension to enhance performance. ProcessMessage is the heart of most SOAP extensions, as the method is called at each stage defined in SoapMessageStage, allowing the SOAP extension to perform the desired behavior of that specific SOAP extension. For SOAP extensions that need to modify the SOAP request or SOAP response, ChainStream provides an opportunity to receive the proposed data to be sent across the wire.

The following TraceExtension SOAP extension outputs the SOAP request and SOAP response to a specified file when applied to an XML Web service method. If the following SOAP extension is installed to run with an XML Web service, the ASPNET user account must have permission to write to the directory in which the log file is written.


using System;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.IO;
using System.Net;

	// Define a SOAP Extension that traces the SOAP request and SOAP
	// response for the XML Web service method the SOAP extension is
	// applied to.

	public class TraceExtension : SoapExtension 
	{
		Stream oldStream;
		Stream newStream;
		string filename;

		// Save the Stream representing the SOAP request or SOAP response into
		// a local memory buffer.
		public override Stream ChainStream( Stream stream )
		{
			oldStream = stream;
			newStream = new MemoryStream();
			return newStream;
		}

		// When the SOAP extension is accessed for the first time, the XML Web
		// service method it is applied to is accessed to store the file
		// name passed in, using the corresponding SoapExtensionAttribute.	
		public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute) 
		{
			return ((TraceExtensionAttribute) attribute).Filename;
		}

		// The SOAP extension was configured to run using a configuration file
		// instead of an attribute applied to a specific XML Web service
		// method.
		public override object GetInitializer(Type WebServiceType) 
		{
			// Return a file name to log the trace information to, based on the
			// type.
			return "C:\\" + WebServiceType.FullName + ".log";    
		}

		// Receive the file name stored by GetInitializer and store it in a
		// member variable for this specific instance.
		public override void Initialize(object initializer) 
		{
			filename = (string) initializer;
		}

		//  If the SoapMessageStage is such that the SoapRequest or
		//  SoapResponse is still in the SOAP format to be sent or received,
		//  save it out to a file.
		public override void ProcessMessage(SoapMessage message) 
		{
			switch (message.Stage) 
			{
				case SoapMessageStage.BeforeSerialize:
					break;
				case SoapMessageStage.AfterSerialize:
					WriteOutput(message);
					break;
				case SoapMessageStage.BeforeDeserialize:
					WriteInput(message);
					break;
				case SoapMessageStage.AfterDeserialize:
					break;
			}
		}

		public void WriteOutput(SoapMessage message)
		{
			newStream.Position = 0;
			FileStream fs = new FileStream(filename, FileMode.Append,
				FileAccess.Write);
			StreamWriter w = new StreamWriter(fs);

			string soapString = (message is SoapServerMessage) ? "SoapResponse" : "SoapRequest";
			w.WriteLine("-----" + soapString + " at " + DateTime.Now);
			w.Flush();
			Copy(newStream, fs);
			w.Close();
			newStream.Position = 0;
			Copy(newStream, oldStream);
		}

		public void WriteInput(SoapMessage message)
		{
			Copy(oldStream, newStream);
			FileStream fs = new FileStream(filename, FileMode.Append,
				FileAccess.Write);
			StreamWriter w = new StreamWriter(fs);

			string soapString = (message is SoapServerMessage) ?
				"SoapRequest" : "SoapResponse";
			w.WriteLine("-----" + soapString + 
				" at " + DateTime.Now);
			w.Flush();
			newStream.Position = 0;
			Copy(newStream, fs);
			w.Close();
			newStream.Position = 0;
		}

		void Copy(Stream from, Stream to) 
		{
			TextReader reader = new StreamReader(from);
			TextWriter writer = new StreamWriter(to);
			writer.WriteLine(reader.ReadToEnd());
			writer.Flush();
		}
	}

	// Create a SoapExtensionAttribute for the SOAP Extension that can be
	// applied to an XML Web service method.
	[AttributeUsage(AttributeTargets.Method)]
	public class TraceExtensionAttribute : SoapExtensionAttribute 
	{

		private string filename = "c:\\log.txt";
		private int priority;

		public override Type ExtensionType 
		{
			get { return typeof(TraceExtension); }
		}

		public override int Priority 
		{
			get { return priority; }
			set { priority = value; }
		}

		public string Filename 
		{
			get 
			{
				return filename;
			}
			set 
			{
				filename = value;
			}
		}
	}


.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Community Additions

ADD
Show:
© 2014 Microsoft