1Using#region Using
  2
  3using System;
  4using System.IO;
  5using System.Xml;
  6using System.Net;
  7using System.Text;
  8using System.Text.RegularExpressions;
  9using LiveBlog.Core;
 10
 11#endregion
 12
 13namespace LiveBlog.Core.Ping
 14...{
 15  /**//// <summary>
 16  /// Sends pingbacks to website that the blog links to.
 17  /// </summary>
 18  public static class Pingback
 19  ...{
 20
 21    /**//// <summary>
 22    /// Sends pingbacks to the targetUrl.
 23    /// </summary>
 24    public static void Send(Uri sourceUrl, Uri targetUrl)
 25    ...{
 26            if (!BlogSettings.Instance.EnablePingBackSend)
 27                return;
 28
 29      if (sourceUrl == null || targetUrl == null)
 30        return;
 31
 32      try
 33      ...{
 34        HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(targetUrl);
 35        request.Credentials = CredentialCache.DefaultNetworkCredentials;
 36        HttpWebResponse response = (HttpWebResponse)request.GetResponse();
 37        string pingUrl = response.Headers["x-pingback"];
 38        Uri url;
 39        if (!string.IsNullOrEmpty(pingUrl) && Uri.TryCreate(pingUrl, UriKind.Absolute, out url))
 40        ...{
 41          OnSending(url);
 42          request = (HttpWebRequest)HttpWebRequest.Create(url);
 43          request.Method = "POST";
 44          request.Timeout = 10000;
 45          request.ContentType = "text/xml";
 46          request.ProtocolVersion = HttpVersion.Version11;
 47                    request.UserAgent = "Mozilla/4.0 (compatible; MSIE 7.0b; Windows NT 6.0)";
 48          AddXmlToRequest(sourceUrl, targetUrl, request);
 49          request.GetResponse();
 50          OnSent(url);
 51        }
 52      }
 53      catch (Exception)
 54      ...{
 55        // Stops unhandled exceptions that can cause the app pool to recycle
 56      }
 57    }
 58
 59    /**//// <summary>
 60    /// Adds the XML to web request. The XML is the standard
 61    /// XML used by RPC-XML requests.
 62    /// </summary>
 63    private static void AddXmlToRequest(Uri sourceUrl, Uri targetUrl, HttpWebRequest webreqPing)
 64    ...{
 65      Stream stream = (Stream)webreqPing.GetRequestStream();
 66      using (XmlTextWriter writer = new XmlTextWriter(stream, Encoding.ASCII))
 67      ...{
 68        writer.WriteStartDocument(true);
 69        writer.WriteStartElement("methodCall");
 70        writer.WriteElementString("methodName", "pingback.ping");
 71        writer.WriteStartElement("params");
 72
 73        writer.WriteStartElement("param");
 74        writer.WriteStartElement("value");
 75        writer.WriteElementString("string", sourceUrl.ToString());
 76        writer.WriteEndElement();
 77        writer.WriteEndElement();
 78
 79        writer.WriteStartElement("param");
 80        writer.WriteStartElement("value");
 81        writer.WriteElementString("string", targetUrl.ToString());
 82        writer.WriteEndElement();
 83        writer.WriteEndElement();
 84
 85        writer.WriteEndElement();
 86        writer.WriteEndElement();
 87      }
 88    }
 89
 90    Events#region Events
 91
 92    /**//// <summary>
 93    /// Occurs just before a pingback is sent.
 94    /// </summary>
 95    public static event EventHandler<EventArgs> Sending;
 96    private static void OnSending(Uri url)
 97    ...{
 98      if (Sending != null)
 99      ...{
100        Sending(url, new EventArgs());
101      }
102    }
103
104    /**//// <summary>
105    /// Occurs when a pingback has been sent
106    /// </summary>
107    public static event EventHandler<EventArgs> Sent;
108    private static void OnSent(Uri url)
109    ...{
110      if (Sent != null)
111      ...{
112        Sent(url, new EventArgs());
113      }
114    }
115
116    #endregion
117
118  }
119}
120