Add in RSS 1.0 (rdf) support

RssToEmail/Formatters/Rss10FeedFormatter.cs

@@ -0,0 +1,277 @@
+using System;
+using System.Collections.ObjectModel;
+using System.Xml;
+using System.Collections.Generic;
+using System.ServiceModel.Syndication;
+
+namespace RssToEmail.Formatters
+{
+	// From: http://www.4guysfromrolla.com/articles/031809-1.aspx
+    public class Rss10FeedFormatter : SyndicationFeedFormatter
+    {
+        #region Constructors
+        public Rss10FeedFormatter() { }
+
+        public Rss10FeedFormatter(SyndicationFeed feed) : base(feed) { }
+        #endregion
+
+        #region Properties
+        public override string Version
+        {
+            get { return "Rss10"; }
+        }
+
+        public virtual string RdfNamespaceUri
+        {
+            get { return "http://www.w3.org/1999/02/22-rdf-syntax-ns#"; }
+        }
+
+        public virtual string NamespaceUri
+        {
+            get { return "http://purl.org/rss/1.0/"; }
+        }
+        #endregion
+
+        #region Methods
+        #region Read XML Methods
+        public override bool CanRead(System.Xml.XmlReader reader)
+        {
+            if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            return reader.IsStartElement("RDF", this.RdfNamespaceUri);
+        }
+
+        protected override SyndicationFeed CreateFeedInstance()
+        {
+            return new SyndicationFeed();
+        }
+
+        public override void ReadFrom(System.Xml.XmlReader reader)
+        {
+            if (!this.CanRead(reader))
+                throw new XmlException("Unknown RSS 1.0 feed format.");
+
+            this.ReadFeed(reader);
+        }
+
+        private void ReadFeed(XmlReader reader)
+        {
+            this.SetFeed(this.CreateFeedInstance());
+            this.ReadXml(reader, base.Feed);
+        }
+
+        protected virtual void ReadXml(XmlReader reader, SyndicationFeed result)
+        {
+            if (result == null)
+                throw new ArgumentNullException("result");
+            else if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            reader.ReadStartElement();              // Read in <RDF>
+            reader.ReadStartElement("channel");     // Read in <channel>
+            while (reader.IsStartElement())         // Process <channel> children
+            {
+                if (reader.IsStartElement("title"))
+                    result.Title = new TextSyndicationContent(reader.ReadElementString());
+                else if (reader.IsStartElement("link"))
+                    result.Links.Add(new SyndicationLink(new Uri(reader.ReadElementString())));
+                else if (reader.IsStartElement("description"))
+                    result.Description = new TextSyndicationContent(reader.ReadElementString());            
+                else
+                    reader.Skip();
+            }
+            reader.ReadEndElement();                // Read in </channel>
+
+            while (reader.IsStartElement())
+            {
+                if (reader.IsStartElement("item"))
+                {
+                    result.Items = this.ReadItems(reader, result);
+
+                    break;
+                }
+                else
+                    reader.Skip();
+            }
+        }
+
+        protected virtual IEnumerable<SyndicationItem> ReadItems(XmlReader reader, SyndicationFeed feed)
+        {
+            if (feed == null)
+                throw new ArgumentNullException("feed");
+            else if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            Collection<SyndicationItem> items = new Collection<SyndicationItem>();
+            while (reader.IsStartElement("item"))
+            {
+                items.Add(this.ReadItem(reader, feed));
+            }
+
+            return items;
+        }
+
+        protected virtual SyndicationItem ReadItem(XmlReader reader, SyndicationFeed feed)
+        {
+            if (feed == null)
+                throw new ArgumentNullException("feed");
+            else if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            SyndicationItem result = new SyndicationItem();
+            this.ReadItemFrom(reader, result);
+
+            return result;
+        }
+
+        protected virtual void ReadItemFrom(XmlReader reader, SyndicationItem result)
+        {
+            if (result == null)
+                throw new ArgumentNullException("result");
+            else if (reader == null)
+                throw new ArgumentNullException("reader");
+
+            reader.ReadStartElement();
+            while (reader.IsStartElement())
+            {
+                if (reader.IsStartElement("title"))
+                    result.Title = new TextSyndicationContent(reader.ReadElementString());
+                else if (reader.IsStartElement("link"))
+                    result.Links.Add(new SyndicationLink(new Uri(reader.ReadElementString())));
+                else if (reader.IsStartElement("description"))
+                    result.Summary = new TextSyndicationContent(reader.ReadElementString());
+                else
+                    reader.Skip();
+            }
+            reader.ReadEndElement();
+        }
+        #endregion
+
+        #region Write XML Methods
+        public override void WriteTo(System.Xml.XmlWriter writer)
+        {
+            if (writer == null)
+                throw new ArgumentNullException("writer");
+
+            writer.WriteStartElement("rdf", "RDF", this.RdfNamespaceUri);      // Write <RDF>
+            writer.WriteAttributeString("xmlns", this.NamespaceUri);
+            this.WriteFeed(writer);
+            writer.WriteEndElement();
+        }
+
+        protected virtual void WriteFeed(XmlWriter writer)
+        {
+            if (writer == null)
+                throw new ArgumentNullException("writer");
+            if (base.Feed == null)
+                throw new InvalidOperationException("Feed formatter does not have a feed.");
+
+            string alternateLink = string.Empty, selfLink = string.Empty;
+            foreach (SyndicationLink lnk in base.Feed.Links)
+            {
+                if (alternateLink.Length == 0 && lnk.RelationshipType == "alternate")
+                    alternateLink = lnk.Uri.IsAbsoluteUri ? lnk.Uri.AbsoluteUri : lnk.Uri.ToString();
+                else if (selfLink.Length == 0 && lnk.RelationshipType == "self")
+                    selfLink = lnk.Uri.IsAbsoluteUri ? lnk.Uri.AbsoluteUri : lnk.Uri.ToString();
+            }
+
+            if (selfLink.Length == 0 && alternateLink.Length > 0)
+                selfLink = alternateLink;
+            else if (alternateLink.Length == 0 && selfLink.Length > 0)
+                alternateLink = selfLink;
+
+
+            writer.WriteStartElement("channel");     // Write <channel>
+            writer.WriteAttributeString("about", this.RdfNamespaceUri, selfLink);
+
+            if (base.Feed.Title == null || string.IsNullOrEmpty(base.Feed.Title.Text))
+                throw new ArgumentException("Feed title required for RSS 1.0 feeds.");
+            writer.WriteElementString("title", base.Feed.Title.Text);       // Write <title>
+
+
+            if (alternateLink.Length == 0)
+                throw new ArgumentException("Feed link required for RSS 1.0 feeds.");
+            writer.WriteElementString("link", alternateLink);       // Write <link>
+
+
+            if (base.Feed.Description == null || string.IsNullOrEmpty(base.Feed.Description.Text))
+                throw new ArgumentException("Feed title required for RSS 1.0 feeds.");
+            writer.WriteElementString("description", base.Feed.Description.Text);       // Write <description>
+
+
+            writer.WriteStartElement("items");              // Write <items>
+            writer.WriteStartElement("Seq", this.RdfNamespaceUri);
+            foreach (SyndicationItem item in base.Feed.Items)
+            {
+                string itemAlternateLink = GetAlternateLinkForItem(item);
+
+                writer.WriteStartElement("li", this.RdfNamespaceUri);
+                writer.WriteAttributeString("resource", this.RdfNamespaceUri, itemAlternateLink);
+                writer.WriteEndElement();
+            }
+            writer.WriteEndElement();
+            writer.WriteEndElement();
+
+            writer.WriteEndElement();       // Write </channel>
+
+            // Write the <item> elements
+            this.WriteItems(writer, base.Feed.Items);
+        }
+
+        protected virtual void WriteItems(XmlWriter writer, IEnumerable<SyndicationItem> items)
+        {
+            if (writer == null)
+                throw new ArgumentNullException("writer");
+
+            if (items != null)
+                foreach (SyndicationItem item in items)
+                    this.WriteItem(writer, item);
+        }
+
+        protected virtual void WriteItem(XmlWriter writer, SyndicationItem item)
+        {
+            if (writer == null)
+                throw new ArgumentNullException("writer");
+
+            string alternateLink = GetAlternateLinkForItem(item);
+
+            writer.WriteStartElement("item");           // Write <item>
+            writer.WriteAttributeString("about", this.RdfNamespaceUri, alternateLink);
+            this.WriteItemContents(writer, item);
+            writer.WriteEndElement();
+        }
+
+        protected virtual void WriteItemContents(XmlWriter writer, SyndicationItem item)
+        {
+            if (writer == null)
+                throw new ArgumentNullException("writer");
+
+            if (item.Title == null || string.IsNullOrEmpty(item.Title.Text))
+                throw new ArgumentException("Feed title required for RSS 1.0 feeds.");
+            writer.WriteElementString("title", item.Title.Text);       // Write <title>
+
+
+            string alternateLink = GetAlternateLinkForItem(item);
+            if (string.IsNullOrEmpty(alternateLink))
+                throw new ArgumentException("Feed link required for RSS 1.0 feeds.");
+            writer.WriteElementString("link", alternateLink);       // Write <link>
+
+
+            if (base.Feed.Description != null && string.IsNullOrEmpty(item.Summary.Text) == false)
+                writer.WriteElementString("description", item.Summary.Text);       // Write the optional <description>
+        }
+
+        private string GetAlternateLinkForItem(SyndicationItem item)
+        {
+            foreach (SyndicationLink lnk in item.Links)
+                if (lnk.RelationshipType == "alternate")
+                    return lnk.Uri.IsAbsoluteUri ? lnk.Uri.AbsoluteUri : lnk.Uri.ToString();
+
+            // If we reach here, return an empty string
+            return string.Empty;
+        }
+        #endregion
+        #endregion
+    }
+}

RssToEmail/Program.cs

@@ -10,6 +10,7 @@
 using Raven.Client.Embedded;
 using Raven.Database.Server;
 using RssToEmail.Extensions;
+using RssToEmail.Formatters;
 using RssToEmail.Models;
 using log4net;
 
@@ -60,8 +61,29 @@ static void Main(string[] args)
 							stopwatch.Start();
 							using (var f = XmlReader.Create(url))
 							{
-								var feed = SyndicationFeed.Load(f);
-								var from = new MailAddress(ConfigurationManager.AppSettings["from"], feed.Title.Text);
+								SyndicationFeed feed;
+
+								// Try rdf first
+								var rss10FeedParser = new Rss10FeedFormatter();
+								if (rss10FeedParser.CanRead(f))
+								{
+									rss10FeedParser.ReadFrom(f);
+									feed = rss10FeedParser.Feed;
+								}
+								else
+								{
+									feed = SyndicationFeed.Load(f);
+								}
+								var fromTitle = feed.Title.Text;
+								if (string.IsNullOrWhiteSpace(fromTitle))
+								{
+									var author = feed.Authors.FirstOrDefault();
+									if (author != null)
+									{
+										fromTitle = author.Name;
+									}
+								}
+								var from = new MailAddress(ConfigurationManager.AppSettings["from"], fromTitle);
 
 								bool? supportsContentEncoding = null;
 								foreach (var item in feed.Items.Reverse())
@@ -71,16 +93,16 @@ static void Main(string[] args)
 									if (linkUri != null)
 										link = linkUri.Uri.ToString().Split('?').First();
 
-									var id = item.Id;
-									if (item.Id.Contains("?key="))
+									var id = item.Id ?? link;
+									if (id.Contains("?key="))
 									{
-										id = item.Id.Split(new [] { "?key=" }, StringSplitOptions.RemoveEmptyEntries)[1];
+										id = id.Split(new [] { "?key=" }, StringSplitOptions.RemoveEmptyEntries)[1];
 									}
 
 									// Ignore previously processed items
 									if (savedFeed.SentItems.Any(x => 
 											x.Id.Equals(id, StringComparison.OrdinalIgnoreCase) || 
-											x.Id.Equals(item.Id, StringComparison.OrdinalIgnoreCase) || 
+											x.Id.Equals(item.Id ?? "ignore in this case", StringComparison.OrdinalIgnoreCase) || 
 											(!string.IsNullOrEmpty(x.Url) && x.Url == link)))
 										continue;
 
@@ -121,7 +143,7 @@ static void Main(string[] args)
 											}
 
 											var message = new MailMessage(from, to) {
-												Subject = "[New Post] " + item.Title.Text, 
+												Subject = "[New Post] " + HttpUtility.HtmlDecode(item.Title.Text), 
 												Body = content + string.Format("<p style=\"font-size:12px;line-height:1.4em;margin:10px 0px 10px 0px\">View the original article: <a href=\"{0}\">{0}</a></p>", link), 
 												IsBodyHtml = true
 											};

RssToEmail/RssToEmail.csproj

@@ -92,6 +92,7 @@
   </ItemGroup>
   <ItemGroup>
     <Compile Include="Extensions\TimeSpanExtensions.cs" />
+    <Compile Include="Formatters\Rss10FeedFormatter.cs" />
     <Compile Include="Models\FeedItem.cs" />
     <Compile Include="Models\Feed.cs" />
     <Compile Include="Program.cs" />