Logging all outgoing SOAP requests

In my previous post, I showed my implementation for logging outgoing HTTP requests. In this post, I’ll show my implementation for logging outgoing SOAP requests using custom endpoint behaviour.

First I have an implemention of the IClientMessageInspector. IMessageLoggingInspector is mainly for DI.

public interface IMessageLoggingInspector : IClientMessageInspector
{
}

public class MessageLoggingInspector : IMessageLoggingInspector
{
    // AfterReceiveReply is called when the response is received.
    public void AfterReceiveReply(ref Message reply, object correlationState)
    {
        string messageContent = CopyAndGetMessageContent(ref reply);

        var message = new
        {
            Id = correlationState,
            Response = messageContent
        };

        // Code to log response message goes here

    }
    
    // BeforeSendRequest is called before the request is sent. This is where the request should be logged.
    public object BeforeSendRequest(ref Message request, IClientChannel channel)
    {
        var messageContent = CopyAndGetMessageContent(ref request);
        
        var requestId = Guid.NewGuid();
        var message = new
        {
            Id = requestId,
            Body = messageContent,
            RequestDate = DateTime.UtcNow
        };
    
        // Code to log message goes here    

        // Whatever returned here will be the correlationState in AfterReceiveReply method above.
        // You need this to track which response is correlated to a request.
        return requestId;
    }


    private static string CopyAndGetMessageContent(ref Message request)
    {
        var buffer = request.CreateBufferedCopy(int.MaxValue);

        // Create a copy and set it back to request
        // because as soon as the request is read, you cannot read it again.
        request = buffer.CreateMessage(); 
        var originalMessage = buffer.CreateMessage();
        string messageContent;

        using (var stringWriter = new StringWriter())
        {
            using (var xmlTextWriter = new XmlTextWriter(stringWriter))
            {
                originalMessage.WriteMessage(xmlTextWriter);
                xmlTextWriter.Flush();
                xmlTextWriter.Close();
            }
            messageContent = stringWriter.ToString();
        }

        return messageContent;
    }
}

Then I need to implement IEndpointBehavior.

public interface IMessageLoggingBehaviour : IEndpointBehavior
{
}

public class MessageLoggingBehaviour : IMessageLoggingBehaviour
{
    private readonly IMessageLoggingInspector _messageLoggingInspector;

    public MessageLoggingBehaviour(IMessageLoggingInspector messageLoggingInspector)
    {
        _messageLoggingInspector = messageLoggingInspector;
    }

    public void AddBindingParameters(ServiceEndpoint endpoint, BindingParameterCollection bindingParameters)
    {
    }

    public void ApplyClientBehavior(ServiceEndpoint endpoint, ClientRuntime clientRuntime)
    {
        clientRuntime.ClientMessageInspectors.Add(_messageLoggingInspector);
    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
    {
    }

    public void Validate(ServiceEndpoint endpoint)
    {
    }
}

Finally, I just need to add MessageLoggingBehaviour when I create a SOAP client

public class SoapClientFactory
{
    private readonly IMessageLoggingBehaviour _messageLoggingBehaviour;
    
    public SoapClientFactory(IMessageLoggingBehaviour messageLoggingBehaviour)
    {
        _messageLoggingBehaviour = messageLoggingBehaviour;
    }

    public SomeSampleSoapClient GetSampleSoapClient()
    {
        var sampleSoapClient = new SomeSampleSoapClient();
        // More endpoint settings and behaviours go here
      
        // Add messageLoggingBehaviour as the last EndpointBehavior
        client.Endpoint.EndpointBehaviors.Add(messageLoggingBehaviour);
    }
}