Added navigation handler #47

Author: FlorianRappl

src/AngleSharp.Js/JsConfigurationExtensions.cs

@@ -65,6 +65,7 @@ public static IConfiguration WithJs(this IConfiguration configuration)
         {
             var service = new JsScriptingService();
             var observer = new EventAttributeObserver(service);
+            var handler = new JsNavigationHandler(service);
 
             if (!configuration.Has<INavigator>())
             {
@@ -73,6 +74,7 @@ public static IConfiguration WithJs(this IConfiguration configuration)
 
             return configuration
                 .WithOnly(observer)
+                .With(handler)
                 .With(service);
         }
     }

src/AngleSharp.Js/JsNavigationHandler.cs

@@ -0,0 +1,55 @@
+namespace AngleSharp.Js
+{
+    using AngleSharp.Browser;
+    using AngleSharp.Dom;
+    using AngleSharp.Io;
+    using AngleSharp.Scripting;
+    using AngleSharp.Text;
+    using System;
+    using System.IO;
+    using System.Threading;
+    using System.Threading.Tasks;
+
+    /// <summary>
+    /// Represents a handler for javascript: URLs.
+    /// </summary>
+    public class JsNavigationHandler : INavigationHandler
+    {
+        private static readonly String UrlSchema = "javascript";
+        private readonly JsScriptingService _service;
+
+        /// <summary>
+        /// Creates a new navigation handler for javascript: URLs.
+        /// </summary>
+        /// <param name="service">The underlying scripting service.</param>
+        public JsNavigationHandler(JsScriptingService service)
+        {
+            _service = service;
+        }
+
+        /// <inheritdoc />
+        public async Task<IDocument> NavigateAsync(DocumentRequest request, CancellationToken token)
+        {
+            var document = request.Source?.Owner;
+
+            if (document != null)
+            {
+                var loop = document.Context.GetService<IEventLoop>();
+                var options = new ScriptOptions(document, loop);
+                var script = request.Target.Href.Substring(UrlSchema.Length + 1);
+                var content = TextEncoding.Utf8.GetBytes(script);
+                var response = new DefaultResponse
+                {
+                    Address = new Url(document.Url),
+                    Content = new MemoryStream(content),
+                };
+                await _service.EvaluateScriptAsync(response, options, token).ConfigureAwait(false);
+            }
+
+            return document;
+        }
+
+        /// <inheritdoc />
+        public Boolean SupportsProtocol(String protocol) => protocol.Is(UrlSchema);
+    }
+}