U4-7708 Using a RTE Macro Partial Form (SurfaceController) & Doctype Hijack Controller causes problem with submissions

src/Umbraco.Web/Mvc/EnsurePartialViewMacroViewContextFilterAttribute.cs

@@ -0,0 +1,47 @@
+using System.IO;
+using System.Web.Mvc;
+
+namespace Umbraco.Web.Mvc
+{
+    /// <summary>
+    /// This is a special filter which is required for the RTE to be able to render Partial View Macros that 
+    /// contain forms when the RTE value is resolved outside of an MVC view being rendered
+    /// </summary>
+    /// <remarks>
+    /// The entire way that we support partial view macros that contain forms isn't really great, these forms
+    /// need to be executed as ChildActions so that the ModelState,ViewData,TempData get merged into that action
+    /// so the form can show errors, viewdata, etc...
+    /// Under normal circumstances, macros will be rendered after a ViewContext is created but in some cases 
+    /// developers will resolve the RTE value in the controller, in this case the Form won't be rendered correctly
+    /// with merged ModelState from the controller because the special DataToken hasn't been set yet (which is 
+    /// normally done in the UmbracoViewPageOfModel when a real ViewContext is available.
+    /// So we need to detect if the currently rendering controller is IRenderController and if so we'll ensure that
+    /// this DataToken exists before the action executes in case the developer resolves an RTE value that contains
+    /// a partial view macro form.
+    /// </remarks>
+    internal class EnsurePartialViewMacroViewContextFilterAttribute : ActionFilterAttribute
+    {
+        public override void OnActionExecuting(ActionExecutingContext filterContext)
+        {
+            //ignore anything that is not IRenderController
+            if ((filterContext.Controller is IRenderController) == false)
+                return;
+
+            var viewCtx = new ViewContext(
+                filterContext.Controller.ControllerContext, 
+                new DummyView(), 
+                filterContext.Controller.ViewData, filterContext.Controller.TempData, 
+                new StringWriter());
+
+            //set the special data token
+            filterContext.RequestContext.RouteData.DataTokens[Constants.DataTokenCurrentViewContext] = viewCtx;
+        }
+
+        private class DummyView : IView
+        {
+            public void Render(ViewContext viewContext, TextWriter writer)
+            {
+            }
+        }
+    }
+}

src/Umbraco.Web/Mvc/UmbracoViewPageOfTModel.cs

@@ -120,10 +120,9 @@ namespace Umbraco.Web.Mvc
             base.InitializePage();
             if (ViewContext.IsChildAction == false)
             {
-                if (ViewContext.RouteData.DataTokens.ContainsKey(Constants.DataTokenCurrentViewContext) == false)
-                {
-                    ViewContext.RouteData.DataTokens.Add(Constants.DataTokenCurrentViewContext, ViewContext);
-                }
+                //always ensure the special data token is set - this is used purely for partial view macros that contain forms 
+                // and mostly just when rendered within the RTE
+                ViewContext.RouteData.DataTokens[Constants.DataTokenCurrentViewContext] = ViewContext;                
             }
 
         }

src/Umbraco.Web/Umbraco.Web.csproj

@@ -343,6 +343,7 @@
     <Compile Include="Models\Mapping\PropertyGroupDisplayResolver.cs" />
     <Compile Include="Models\PublishedContentWithKeyBase.cs" />
     <Compile Include="Mvc\ControllerContextExtensions.cs" />
+    <Compile Include="Mvc\EnsurePartialViewMacroViewContextFilterAttribute.cs" />
     <Compile Include="Mvc\IRenderController.cs" />
     <Compile Include="Mvc\ModelBindingException.cs" />
     <Compile Include="Mvc\RenderIndexActionSelectorAttribute.cs" />

src/Umbraco.Web/WebBootManager.cs

@@ -198,6 +198,9 @@ namespace Umbraco.Web
             //Wrap viewengines in the profiling engine
             WrapViewEngines(ViewEngines.Engines);
 
+            //add global filters
+            ConfigureGlobalFilters();
+
             //set routes
             CreateRoutes();
 
@@ -224,6 +227,11 @@ namespace Umbraco.Web
             return this;
         }
 
+        internal static void ConfigureGlobalFilters()
+        {
+            GlobalFilters.Filters.Add(new EnsurePartialViewMacroViewContextFilterAttribute());
+        }
+
         internal static void WrapViewEngines(IList<IViewEngine> viewEngines)
         {
             if (viewEngines == null || viewEngines.Count == 0) return;