Added RssFeedDisplay plugin

PluginPack/RssFeedDisplay.cs

@@ -0,0 +1,229 @@
+
+using System;
+using System.Collections.Generic;
+using System.Text;
+using System.Text.RegularExpressions;
+using System.Xml;
+using ScrewTurn.Wiki.PluginFramework;
+using System.Net;
+using System.IO;
+
+namespace ScrewTurn.Wiki.Plugins.PluginPack {
+
+	/// <summary>
+	/// Implements a formatter provider that counts download of files and attachments.
+	/// </summary>
+	public class RssFeedDisplay : IFormatterProviderV30 {
+
+		private IHostV30 _host;
+		private string _config;
+		private bool _enableLogging = true;
+		private static readonly ComponentInformation Info = new ComponentInformation("RSS Feed Display Plugin", "Threeplicate S.r.l.", "3.0.0.206", "http://www.screwturn.eu", "http://www.screwturn.eu/Version/PluginPack/RssFeedDisplay.txt");
+
+		private static readonly Regex RssRegex = new Regex(@"{RSS:http://(.+?)}",
+			RegexOptions.Compiled | RegexOptions.Singleline | RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
+
+		/// <summary>
+		/// Specifies whether or not to execute Phase 1.
+		/// </summary>
+		public bool PerformPhase1 {
+			get { return false; }
+		}
+
+		/// <summary>
+		/// Specifies whether or not to execute Phase 2.
+		/// </summary>
+		public bool PerformPhase2 {
+			get { return false; }
+		}
+
+		/// <summary>
+		/// Specifies whether or not to execute Phase 3.
+		/// </summary>
+		public bool PerformPhase3 {
+			get { return true; }
+		}
+
+		/// <summary>
+		/// Gets the execution priority of the provider (0 lowest, 100 highest).
+		/// </summary>
+		public int ExecutionPriority {
+			get { return 50; }
+		}
+
+		/// <summary>
+		/// Performs a Formatting phase.
+		/// </summary>
+		/// <param name="raw">The raw content to Format.</param>
+		/// <param name="context">The Context information.</param>
+		/// <param name="phase">The Phase.</param>
+		/// <returns>The Formatted content.</returns>
+		public string Format(string raw, ContextInformation context, FormattingPhase phase) {
+			// {RSS:FeedAddress}
+			// FeedAddress not found -> ignored
+
+			StringBuilder buffer = new StringBuilder(raw);
+
+			try {
+
+				KeyValuePair<int, string> block = FindAndRemoveFirstOccurrence(buffer);
+
+				while(block.Key != -1) {
+					string blockHash = block.Value.ToString();
+
+					string result = null;
+
+					if(System.Web.HttpContext.Current != null) {
+						result = System.Web.HttpContext.Current.Cache[blockHash] as string;
+					}
+
+					if(result == null) {
+						XmlDocument feedXml = GetXml(block.Value.ToString().Substring(5, block.Value.ToString().Length - 6));
+						XmlNode node = feedXml.DocumentElement;
+						XmlNode itemTitle = node.SelectNodes("/rss/channel/item/title")[0];
+						XmlNode itemLink = node.SelectNodes("/rss/channel/item/link")[0];
+						XmlNode itemContent = node.SelectNodes("/rss/channel/item/description")[0];
+						String itemContentStr = StripHtml(itemContent.InnerText);
+						itemContentStr = (itemContentStr.Length > 350 && itemContentStr.Substring(347, 5) != "[...]") ? itemContentStr.Substring(0, itemContentStr.IndexOf(" ", 345)) + " [...]" : itemContentStr;
+						result = @"<div class=""rssfeed"">
+									<span class=""rsstitle"">
+									 <a href=""" + itemLink.InnerText + @""" target=""_blank"" >" + itemTitle.InnerText + @"</a>
+									</span>
+									<br />
+									<span class=""rsscontent"">" + itemContentStr + @"</span>
+								   </div>";
+						if(System.Web.HttpContext.Current != null) {
+							System.Web.HttpContext.Current.Cache.Add(blockHash, result, null, DateTime.Now.AddMinutes(60),
+								System.Web.Caching.Cache.NoSlidingExpiration, System.Web.Caching.CacheItemPriority.Normal, null);
+						}
+					}
+
+					buffer.Insert(block.Key, result);
+
+					block = FindAndRemoveFirstOccurrence(buffer);
+				}
+			}
+			catch(Exception ex) {
+				LogWarning(string.Format("Exception occurred: {0}", ex.Message));
+				return null;
+			}
+			return buffer.ToString();
+		}
+
+		/// <summary>
+		/// Produces an API call, then returns the results as an Xml Document
+		/// </summary>
+		/// <param name="Url">The Url to the specific API call</param>
+		/// <returns></returns>
+		private XmlDocument GetXml(string Url) {
+			try {
+				var results = new XmlDocument();
+				Url = string.Format("{0}", Url);
+				var request = WebRequest.Create(Url);
+				var response = request.GetResponse();
+				using(var reader = new StreamReader(response.GetResponseStream())) {
+					var xmlString = reader.ReadToEnd();
+					try {
+						results.LoadXml(xmlString);
+					}
+					catch {
+						LogWarning("Received Unexpected Response from Unfuddle Server.");
+					}
+				}
+				return results;
+			}
+			catch(Exception ex) {
+				LogWarning(string.Format("Exception occurred: {0}", ex.Message));
+				return null;
+			}
+		}
+
+		/// <summary>
+		/// Finds and removes the first occurrence of the custom tag.
+		/// </summary>
+		/// <param name="buffer">The buffer.</param>
+		/// <returns>The index->content data.</returns>
+		private static KeyValuePair<int, string> FindAndRemoveFirstOccurrence(StringBuilder buffer) {
+			Match match = RssRegex.Match(buffer.ToString());
+
+			if(match.Success) {
+				buffer.Remove(match.Index, match.Length);
+
+				return new KeyValuePair<int, string>(match.Index, match.Value);
+			}
+
+			return new KeyValuePair<int, string>(-1, null);
+		}
+
+		/// <summary>
+		/// Removes all HTML markup from a string.
+		/// </summary>
+		/// <param name="content">The string.</param>
+		/// <returns>The result.</returns>
+		private static string StripHtml(string content) {
+			if(string.IsNullOrEmpty(content)) return "";
+
+			StringBuilder sb = new StringBuilder(Regex.Replace(content, "<[^>]*>", " "));
+			sb.Replace("&nbsp;", "");
+			sb.Replace("  ", " ");
+			return sb.ToString();
+		}
+
+		/// <summary>
+		/// Prepares the title of an item for display (always during phase 3).
+		/// </summary>
+		/// <param name="title">The input title.</param>
+		/// <param name="context">The context information.</param>
+		/// <returns>The prepared title (no markup allowed).</returns>
+		public string PrepareTitle(string title, ContextInformation context) {
+			return title;
+		}
+
+		/// <summary>
+		/// Initializes the Storage Provider.
+		/// </summary>
+		/// <param name="host">The Host of the Component.</param>
+		/// <param name="config">The Configuration data, if any.</param>
+		/// <remarks>If the configuration string is not valid, the methoud should throw a <see cref="InvalidConfigurationException"/>.</remarks>
+		public void Init(IHostV30 host, string config) {
+			this._host = host;
+			this._config = config != null ? config : "";
+
+			if(this._config.ToLowerInvariant() == "nolog") _enableLogging = false;
+		}
+
+		/// <summary>
+		/// Logs a warning.
+		/// </summary>
+		/// <param name="message">The message.</param>
+		private void LogWarning(string message) {
+			if(_enableLogging) {
+				_host.LogEntry(message, LogEntryType.Warning, null, this);
+			}
+		}
+
+		/// <summary>
+		/// Method invoked on shutdown.
+		/// </summary>
+		/// <remarks>This method might not be invoked in some cases.</remarks>
+		public void Shutdown() {
+			// Nothing to do
+		}
+
+		/// <summary>
+		/// Gets the Information about the Provider.
+		/// </summary>
+		public ComponentInformation Information {
+			get { return Info; }
+		}
+
+		/// <summary>
+		/// Gets a brief summary of the configuration string format, in HTML. Returns <c>null</c> if no configuration is needed.
+		/// </summary>
+		public string ConfigHelpHtml {
+			get { return null; }
+		}
+
+	}
+
+}