Prelim. about impl.

Author: FlorianRappl

src/AngleSharp.Io/AngleSharp.Io.csproj

@@ -52,6 +52,7 @@
     <Compile Include="Extensions\GeneralExtensions.cs" />
     <Compile Include="Dom\WebSocket.cs" />
     <Compile Include="Interfaces\IStorage.cs" />
+    <Compile Include="Network\AboutRequester.cs" />
     <Compile Include="Network\FileRequester.cs" />
     <Compile Include="Network\FtpRequester.cs" />
     <Compile Include="Network\HttpClientRequester.cs" />

src/AngleSharp.Io/IoConfigurationExtensions.cs

@@ -19,7 +19,14 @@ public static class IoConfigurationExtensions
         /// <returns>The new configuration.</returns>
         public static IConfiguration WithRequesters(this IConfiguration configuration, Action<ConfigurationExtensions.LoaderSetup> setup = null)
         {
-            var requesters = new IRequester[] { new HttpClientRequester(), new DataRequester(), new FtpRequester(), new FileRequester() };
+            var requesters = new IRequester[] 
+            {
+                new HttpClientRequester(),
+                new DataRequester(),
+                new FtpRequester(),
+                new FileRequester(),
+                new AboutRequester()
+            };
             return configuration.WithDefaultLoader(setup, requesters);
         }
 
@@ -35,7 +42,14 @@ public static IConfiguration WithRequesters(this IConfiguration configuration, A
         public static IConfiguration WithRequesters(this IConfiguration configuration, HttpMessageHandler httpMessageHandler, Action<ConfigurationExtensions.LoaderSetup> setup = null)
         {
             var httpClient = new HttpClient(httpMessageHandler);
-            var requesters = new IRequester[] { new HttpClientRequester(httpClient), new DataRequester(), new FtpRequester(), new FileRequester() };
+            var requesters = new IRequester[] 
+            {
+                new HttpClientRequester(httpClient),
+                new DataRequester(),
+                new FtpRequester(),
+                new FileRequester(),
+                new AboutRequester()
+            };
             return configuration.WithDefaultLoader(setup, requesters);
         }
     }

src/AngleSharp.Io/Network/AboutRequester.cs

@@ -0,0 +1,74 @@
+namespace AngleSharp.Io.Network
+{
+    using AngleSharp.Network;
+    using System;
+    using System.Collections.Generic;
+    using System.Threading;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// Requester to perform about:// requests.
+    /// </summary>
+    public class AboutRequester : IRequester
+    {
+        private readonly Dictionary<String, Func<IRequest, CancellationToken, Task<IResponse>>> _routes;
+
+        /// <summary>
+        /// Creates a new about requester.
+        /// </summary>
+        public AboutRequester()
+        {
+            _routes = new Dictionary<String, Func<IRequest, CancellationToken, Task<IResponse>>>();
+        }
+
+        /// <summary>
+        /// Sets the route for the given address.
+        /// </summary>
+        /// <param name="address">The address of the route.</param>
+        /// <param name="route">The route to use.</param>
+        public void SetRoute(String address, Func<IRequest, CancellationToken, Task<IResponse>> route)
+        {
+            _routes[address] = route;
+        }
+
+        /// <summary>
+        /// Gets the route for the given address, if any.
+        /// </summary>
+        /// <param name="address">The address of the route to obtain.</param>
+        /// <returns>The route, if any.</returns>
+        public Func<IRequest, CancellationToken, Task<IResponse>> GetRoute(String address)
+        {
+            var route = default(Func<IRequest, CancellationToken, Task<IResponse>>);
+            _routes.TryGetValue(address, out route);
+            return route;
+        }
+
+        /// <summary>
+        /// Performs an asynchronous request that can be cancelled.
+        /// </summary>
+        /// <param name="request">The options to consider.</param>
+        /// <param name="cancel">The token for cancelling the task.</param>
+        /// <returns>The task that will eventually give the response data.</returns>
+        public Task<IResponse> RequestAsync(IRequest request, CancellationToken cancel)
+        {
+            var route = GetRoute(request.Address.Data);
+
+            if (route != null)
+            {
+                return route.Invoke(request, cancel);
+            }
+
+            return Task.FromResult(default(IResponse));
+        }
+
+        /// <summary>
+        /// Checks if the given protocol is supported.
+        /// </summary>
+        /// <param name="protocol">The protocol to check for, e.g. file.</param>
+        /// <returns>True if the protocol is supported, otherwise false.</returns>
+        public Boolean SupportsProtocol(String protocol)
+        {
+            return !String.IsNullOrEmpty(protocol) && protocol.Equals("about");
+        }
+    }
+}