Add a few new ways to drag/drop a URL - from a few Chrome extensions or the page URL itself - page URL only supports single links right now

Application/FeedCenter.csproj

@@ -157,6 +157,10 @@
     <Reference Include="EntityFramework.SqlServerCompact">
       <HintPath>..\packages\EntityFramework.SqlServerCompact.6.1.1\lib\net45\EntityFramework.SqlServerCompact.dll</HintPath>
     </Reference>
+    <Reference Include="HtmlAgilityPack, Version=1.4.9.0, Culture=neutral, PublicKeyToken=bd319b19eaf3b43a, processorArchitecture=MSIL">
+      <HintPath>..\packages\HtmlAgilityPack.1.4.9\lib\Net45\HtmlAgilityPack.dll</HintPath>
+      <Private>True</Private>
+    </Reference>
     <Reference Include="System" />
     <Reference Include="System.ComponentModel.DataAnnotations" />
     <Reference Include="System.configuration" />

Application/FeedParsers/FeedParserBase.cs

@@ -119,7 +119,7 @@ namespace FeedCenter.FeedParsers
             throw new ArgumentException($"Feed type {feedType} is not supported");
         }
 
-        private static FeedType DetectFeedType(string feedText)
+        public static FeedType DetectFeedType(string feedText)
         {
             try
             {
@@ -150,7 +150,9 @@ namespace FeedCenter.FeedParsers
             }
             catch (Exception exception)
             {
-                throw new InvalidFeedFormatException(exception);
+                Tracer.WriteException(exception);                
+                
+                return FeedType.Unknown;
             }
         }
 

Application/Feeds/Feed.cs

@@ -99,6 +99,18 @@ namespace FeedCenter
             return await Task.Run(() => Read(database, forceRead));
         }
 
+        public Tuple<FeedType, string> DetectFeedType()
+        {
+            var retrieveResult = RetrieveFeed();
+
+            if (retrieveResult.Item1 != FeedReadResult.Success)
+            {
+                return new Tuple<FeedType, string>(FeedType.Unknown, string.Empty);
+            }
+
+            return new Tuple<FeedType, string>(FeedParserBase.DetectFeedType(retrieveResult.Item2), retrieveResult.Item2);
+        }
+
         private Tuple<FeedReadResult, string> RetrieveFeed()
         {
             try

Application/MainWindow.xaml.cs

@@ -10,6 +10,7 @@ using System.Collections.Generic;
 using System.ComponentModel;
 using System.IO;
 using System.Linq;
+using System.Net;
 using System.Threading;
 using System.Web.UI;
 using System.Windows;
@@ -17,11 +18,14 @@ using System.Windows.Controls;
 using System.Windows.Input;
 using System.Windows.Interop;
 using System.Windows.Media;
+using Common.Internet;
 
 namespace FeedCenter
 {
     public partial class MainWindow
     {
+        private readonly string[] _chromeExtensions = { "chrome-extension://ehojfdcmnajoklleckniaifaijfnkpbi/subscribe.html?", "chrome-extension://nlbjncdgjeocebhnmkbbbdekmmmcbfjd/subscribe.html?" };
+
         #region Member variables
 
         private int _feedIndex;
@@ -788,6 +792,37 @@ namespace FeedCenter
             feed.Source = feedUrl;
             feed.Category = _database.DefaultCategory;
 
+            // Try to detect the feed type
+            var feedTypeResult = feed.DetectFeedType();
+
+            // If we can't figure it out it could be an HTML page
+            if (feedTypeResult.Item1 == FeedType.Unknown)
+            {
+                // Only check if the feed was able to be read - otherwise fall through and show the dialog
+                if (feedTypeResult.Item2.Length > 0)
+                {
+                    // Create and load an HTML document with the text
+                    var htmlDocument = new HtmlAgilityPack.HtmlDocument();
+                    htmlDocument.LoadHtml(feedTypeResult.Item2);
+
+                    // Look for all RSS or atom links in the document
+                    var rssLinks = htmlDocument.DocumentNode.Descendants("link")
+                        .Where(n => n.Attributes["type"] != null && (n.Attributes["type"].Value == "application/rss+xml" || n.Attributes["type"].Value == "application/atom+xml"))
+                        .Select(n => UrlHelper.GetAbsoluteUrlString(feed.Source, n.Attributes["href"].Value))
+                        .ToArray();
+
+                    // If there was only one link found then switch to feed to it
+                    if (rssLinks.Length == 1)
+                    {
+                        feed.Source = rssLinks[0];
+                    }
+                    else
+                    {
+                        // TODO - show dialog to choose feed
+                    }
+                }
+            }
+
             // Read the feed for the first time
             var feedReadResult = feed.Read(_database);
 
@@ -899,6 +934,16 @@ namespace FeedCenter
             // Get the data as a string
             var data = (string) e.Data.GetData(DataFormats.Text);
 
+            // Check to see if the data starts with any known Chrome extension
+            var chromeExtension = _chromeExtensions.FirstOrDefault(c => data.StartsWith(c));
+
+            // Remove the Chrome extension URL and decode the URL
+            if (chromeExtension != null)
+            {
+                data = data.Substring(chromeExtension.Length);
+                data = WebUtility.UrlDecode(data);
+            }
+
             // Handle the new feed but allow the drag/drop to complete
             Dispatcher.BeginInvoke(new NewFeedDelegate(HandleNewFeed), data);
         }

Application/packages.config

@@ -2,5 +2,6 @@
 <packages>
   <package id="EntityFramework" version="6.1.1" targetFramework="net45" />
   <package id="EntityFramework.SqlServerCompact" version="6.1.1" targetFramework="net45" />
+  <package id="HtmlAgilityPack" version="1.4.9" targetFramework="net451" />
   <package id="Microsoft.SqlServer.Compact" version="4.0.8854.1" targetFramework="net45" />
 </packages>

Setup/Product.wxs

@@ -175,6 +175,8 @@
 
         <File Source="$(var.FeedCenter.TargetDir)\Common.Wpf.MarkupExtensions.dll" />
 
+        <File Source="$(var.FeedCenter.TargetDir)\HtmlAgilityPack.dll" />
+        
         <File Source="$(var.FeedCenter.TargetDir)\EntityFramework.dll" />
         <File Source="$(var.FeedCenter.TargetDir)\EntityFramework.SqlServer.dll" />
         <File Source="$(var.FeedCenter.TargetDir)\EntityFramework.SqlServerCompact.dll" />