Implemented a UrlHelper token provider.

This enables users to create hyperlinks based on route values that are dynamically turned into actual urls.

src/Orchard.Web/Modules/Orchard.Tokens/Orchard.Tokens.csproj

@@ -99,6 +99,7 @@
   <ItemGroup>
     <Compile Include="Controllers\AdminController.cs" />
     <Compile Include="Providers\ContentTokens.cs" />
+    <Compile Include="Providers\UrlHelperTokens.cs" />
     <Compile Include="Providers\RssPartFeedItemBuilder.cs" />
     <Compile Include="Providers\RequestTokens.cs" />
     <Compile Include="Providers\DateTokens.cs" />

src/Orchard.Web/Modules/Orchard.Tokens/Providers/UrlHelperTokens.cs

@@ -0,0 +1,50 @@
+using System;
+using System.Linq;
+using System.Web.Mvc;
+using System.Web.Routing;
+using Orchard.Localization;
+
+namespace Orchard.Tokens.Providers {
+    public class UrlHelperTokens : ITokenProvider {
+        private readonly IWorkContextAccessor _workContextAccessor;
+        private readonly UrlHelper _urlHelper;
+
+        public UrlHelperTokens(IWorkContextAccessor workContextAccessor, UrlHelper urlHelper) {
+            _workContextAccessor = workContextAccessor;
+            _urlHelper = urlHelper;
+            T = NullLocalizer.Instance;
+        }
+
+        public Localizer T { get; set; }
+
+        public void Describe(DescribeContext context) {
+            context.For("Url", T("UrlHelper actions"), T("UrlHelper actions."))
+                .Token("Action:*", T("Action:<actionname,controllername[,area=MyModuleName][,customValue=42]>"), T("The route values to evaluate."));
+        }
+
+        public void Evaluate(EvaluateContext context) {
+            if (_workContextAccessor.GetContext().HttpContext == null) {
+                return;
+            }
+
+            context.For("Url", () => _urlHelper)
+                .Token(token => token.StartsWith("Action:", StringComparison.OrdinalIgnoreCase) ? token.Substring("Action:".Length) : null, GetRoute);
+        }
+
+        private object GetRoute(string token, UrlHelper url) {
+            var items = token.Split(new[]{','}, StringSplitOptions.RemoveEmptyEntries);
+            var actionName = items[0];
+            var controllerName = items[1];
+            var routeValues = new RouteValueDictionary {
+                {"action", actionName},
+                {"controller", controllerName}
+            };
+
+            foreach (var parts in items.Skip(2).Select(item => item.Split(new[] {'='}, StringSplitOptions.RemoveEmptyEntries))) {
+                routeValues[parts[0]] = parts[1];
+            }
+
+            return url.RouteUrl(routeValues);
+        }
+    }
+}