//============================================================
// CLASS SUMMARY
//============================================================
/// <summary>
/// Provides example code for the TrackbackClient class.
/// </summary>
public static void ClassExample()
{
#region TrackbackClient
// Initialize the Trackback peer-to-peer notification protocol client
TrackbackClient client = new TrackbackClient();
client.Host = new Uri("http://www.example.com/trackback/5");
// Construct the trackback message to be sent
TrackbackMessage message = new TrackbackMessage(new Uri("http://www.bar.com/"));
message.Encoding = Encoding.UTF8;
message.WeblogName = "Foo";
message.Title = "Foo Bar";
message.Excerpt = "My Excerpt";
// Send a synchronous trackback ping
TrackbackResponse response = client.Send(message);
// Verify response to the trackback ping
if (response != null)
{
if (response.HasError)
{
// Use the TrackbackResponse.ErrorMessage property to determine the reason the trackback ping failed
}
}
#endregion
}
/// <summary>
/// Sends the specified message to an Trackback server to execute an Trackback ping request.
/// This method does not block the calling thread and allows the caller to pass an object to the method that is invoked when the operation completes.
/// </summary>
/// <param name="message">A <see cref="TrackbackMessage"/> that represents the information needed to execute the Trackback ping request.</param>
/// <param name="userToken">A user-defined object that is passed to the method invoked when the asynchronous operation completes.</param>
/// <remarks>
/// <para>
/// To receive notification when the Trackback ping request has been sent or the operation has been cancelled, add an event handler to the <see cref="SendCompleted"/> event.
/// You can cancel a <see cref="SendAsync(TrackbackMessage, Object)"/> operation by calling the <see cref="SendAsyncCancel()"/> method.
/// </para>
/// </remarks>
/// <exception cref="ArgumentNullException">The <paramref name="message"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="InvalidOperationException">The <see cref="Host"/> is a <b>null</b> reference (Nothing in Visual Basic).</exception>
/// <exception cref="InvalidOperationException">This <see cref="TrackbackClient"/> has a <see cref="SendAsync(TrackbackMessage, Object)"/> call in progress.</exception>
//[HostProtectionAttribute(SecurityAction.LinkDemand, ExternalThreading = true)]
public void SendAsync(TrackbackMessage message, Object userToken)
{
Guard.ArgumentNotNull(message, "message");
if (this.Host == null)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The Host property has not been initialized. \n\r Message payload: {0}", message));
}
else if (this.SendOperationInProgress)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The TrackbackClient has a SendAsync call in progress. \n\r Message payload: {0}", message));
}
this.SendOperationInProgress = true;
this.AsyncSendHasBeenCancelled = false;
asyncHttpWebRequest = TrackbackClient.CreateWebRequest(this.Host, this.UserAgent, message, this.UseDefaultCredentials, this.clientOptions);
object[] state = new object[6] {
asyncHttpWebRequest, this, this.Host, message, this.clientOptions, userToken
};
IAsyncResult result = asyncHttpWebRequest.BeginGetResponse(new AsyncCallback(AsyncSendCallback), state);
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(AsyncTimeoutCallback), state, this.Timeout, true);
}
/// <summary>
/// Called when a corresponding asynchronous send operation completes.
/// </summary>
/// <param name="result">The result of the asynchronous operation.</param>
private static void AsyncSendCallback(IAsyncResult result)
{
TrackbackResponse response = null;
WebRequest httpWebRequest = null;
TrackbackClient client = null;
Uri host = null;
TrackbackMessage message = null;
WebRequestOptions options = null;
object userToken = null;
if (result.IsCompleted)
{
object[] parameters = (object[])result.AsyncState;
httpWebRequest = parameters[0] as WebRequest;
client = parameters[1] as TrackbackClient;
host = parameters[2] as Uri;
message = parameters[3] as TrackbackMessage;
options = parameters[4] as WebRequestOptions;
userToken = parameters[5];
if (client != null)
{
WebResponse httpWebResponse = (WebResponse)httpWebRequest.EndGetResponse(result);
response = new TrackbackResponse(httpWebResponse);
client.OnMessageSent(new TrackbackMessageSentEventArgs(host, message, response, options, userToken));
client.SendOperationInProgress = false;
}
}
}
//============================================================
// CALLBACK DELEGATE METHODS
//============================================================
#region AsyncSendCallback(IAsyncResult result)
/// <summary>
/// Called when a corresponding asynchronous send operation completes.
/// </summary>
/// <param name="result">The result of the asynchronous operation.</param>
private static void AsyncSendCallback(IAsyncResult result)
{
//------------------------------------------------------------
// Local members
//------------------------------------------------------------
TrackbackResponse response = null;
WebRequest httpWebRequest = null;
TrackbackClient client = null;
Uri host = null;
TrackbackMessage message = null;
WebRequestOptions options = null;
object userToken = null;
//------------------------------------------------------------
// Determine if the async send operation completed
//------------------------------------------------------------
if (result.IsCompleted)
{
//------------------------------------------------------------
// Extract the send operations parameters from the user state
//------------------------------------------------------------
object[] parameters = (object[])result.AsyncState;
httpWebRequest = parameters[0] as WebRequest;
client = parameters[1] as TrackbackClient;
host = parameters[2] as Uri;
message = parameters[3] as TrackbackMessage;
options = parameters[4] as WebRequestOptions;
userToken = parameters[5];
//------------------------------------------------------------
// Verify expected parameters were found
//------------------------------------------------------------
if (client != null)
{
//------------------------------------------------------------
// Get the Trackback response to the Trackback ping request
//------------------------------------------------------------
WebResponse httpWebResponse = (WebResponse)httpWebRequest.EndGetResponse(result);
//------------------------------------------------------------
// Extract the Trackback response to the Trackback ping request
//------------------------------------------------------------
response = new TrackbackResponse(httpWebResponse);
//------------------------------------------------------------
// Raise SendCompleted event to notify registered handlers of state change
//------------------------------------------------------------
client.OnMessageSent(new TrackbackMessageSentEventArgs(host, message, response, options, userToken));
//------------------------------------------------------------
// Reset async operation in progress indicator
//------------------------------------------------------------
client.SendOperationInProgress = false;
}
}
}
public void SendAsync(TrackbackMessage message, Object userToken)
{
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(message, "message");
//------------------------------------------------------------
// Validate client state
//------------------------------------------------------------
if (this.Host == null)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The Host property has not been initialized. \n\r Message payload: {0}", message));
}
else if (this.SendOperationInProgress)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The TrackbackClient has a SendAsync call in progress. \n\r Message payload: {0}", message));
}
//------------------------------------------------------------
// Set async operation tracking indicators
//------------------------------------------------------------
this.SendOperationInProgress = true;
this.AsyncSendHasBeenCancelled = false;
//------------------------------------------------------------
// Build Trackback web request used to send the Trackback ping request
//------------------------------------------------------------
asyncHttpWebRequest = TrackbackClient.CreateWebRequest(this.Host, this.UserAgent, message, this.UseDefaultCredentials, this.clientOptions);
//------------------------------------------------------------
// Get the async response to the web request
//------------------------------------------------------------
object[] state = new object[6] {
asyncHttpWebRequest, this, this.Host, message, this.clientOptions, userToken
};
IAsyncResult result = asyncHttpWebRequest.BeginGetResponse(new AsyncCallback(AsyncSendCallback), state);
//------------------------------------------------------------
// Register the timeout callback
//------------------------------------------------------------
ThreadPool.RegisterWaitForSingleObject(result.AsyncWaitHandle, new WaitOrTimerCallback(AsyncTimeoutCallback), state, this.Timeout, true);
}
//============================================================
// PUBLIC METHODS
//============================================================
#region Send(TrackbackMessage message)
/// <summary>
/// Sends the specified message to a Trackback server to execute an Trackback ping request.
/// </summary>
/// <param name="message">A <see cref="TrackbackMessage"/> that represents the information needed to execute the Trackback ping request.</param>
/// <returns>A <see cref="TrackbackResponse"/> that represents the server's response to the Trackback ping request.</returns>
/// <exception cref="ArgumentNullException">The <paramref name="message"/> is a null reference (Nothing in Visual Basic).</exception>
/// <exception cref="InvalidOperationException">The <see cref="Host"/> is a <b>null</b> reference (Nothing in Visual Basic).</exception>
/// <exception cref="InvalidOperationException">This <see cref="TrackbackClient"/> has a <see cref="SendAsync(TrackbackMessage, Object)"/> call in progress.</exception>
public TrackbackResponse Send(TrackbackMessage message)
{
//------------------------------------------------------------
// Local members
//------------------------------------------------------------
TrackbackResponse response = null;
//------------------------------------------------------------
// Validate parameter
//------------------------------------------------------------
Guard.ArgumentNotNull(message, "message");
//------------------------------------------------------------
// Validate client state
//------------------------------------------------------------
if (this.Host == null)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The Host property has not been initialized. \n\r Message payload: {0}", message));
}
else if (this.SendOperationInProgress)
{
throw new InvalidOperationException(String.Format(null, "Unable to send Trackback message. The TrackbackClient has a SendAsync call in progress. \n\r Message payload: {0}", message));
}
//------------------------------------------------------------
// Execute the Trackback ping request
//------------------------------------------------------------
WebRequest webRequest = TrackbackClient.CreateWebRequest(this.Host, this.UserAgent, message, this.UseDefaultCredentials, this.clientOptions);
using (WebResponse webResponse = (WebResponse)webRequest.GetResponse())
{
response = new TrackbackResponse(webResponse);
}
return(response);
}
