Roughing out starting point of multi-pass rendering for theme support

--HG--
extra : convert_revision : svn%3A5ff7c347-ad56-4c35-b696-ccb81de16e03/trunk%4044044

src/Orchard/Mvc/Html/LayoutHelperExtensions.cs

@@ -0,0 +1,15 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Web.Mvc;
+using Orchard.Mvc.ViewEngines;
+
+namespace Orchard.Mvc.Html {
+    public static class LayoutHelperExtensions {
+        public static void RenderBody(this HtmlHelper html) {
+            var layoutContext = OrchardLayoutContext.From(html.ViewContext);
+            html.ViewContext.HttpContext.Response.Output.Write(layoutContext.BodyContent);
+        }
+    }
+}

src/Orchard/Mvc/ViewEngines/LayoutView.cs

@@ -0,0 +1,35 @@
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Web.Mvc;
+
+namespace Orchard.Mvc.ViewEngines {
+    public class LayoutView : IView {
+        private IView[] _views;
+
+        public LayoutView(IEnumerable<IView> views) {
+            _views = views.ToArray();
+        }
+
+        public void Render(ViewContext viewContext, TextWriter writer) {
+
+            var orchardViewContext = OrchardLayoutContext.From(viewContext);
+
+            for (var index = 0; index != _views.Length; ++index)
+            {
+                var view = _views[index];
+                if (index == _views.Length - 1) {
+                    view.Render(viewContext, writer);
+                }
+                else {
+                    //TEMP: to be replaced with an efficient spooling writer
+                    var childWriter = new StringWriter();
+                    view.Render(viewContext, childWriter);
+                    orchardViewContext.BodyContent = childWriter.ToString();
+                }
+            }
+        }
+    }
+}

src/Orchard/Mvc/ViewEngines/LayoutViewEngine.cs

@@ -0,0 +1,62 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Web.Mvc;
+
+namespace Orchard.Mvc.ViewEngines {
+    public class LayoutViewEngine : IViewEngine {
+        private readonly ViewEngineCollection _viewEngines;
+
+        public LayoutViewEngine(ViewEngineCollection viewEngines) {
+            _viewEngines = viewEngines;
+        }
+
+        public ViewEngineResult FindPartialView(ControllerContext controllerContext, string partialViewName, bool useCache) {
+            return new ViewEngineResult(Enumerable.Empty<string>());
+        }
+
+        public ViewEngineResult FindView(
+            ControllerContext controllerContext,
+            string viewName,
+            string masterName,
+            bool useCache) {
+
+            // TODO: is there an optimization around useCache for
+            // this implementation? since IView can't re-execute, maybe not...
+
+            // if action returned a View with explicit master - 
+            // this will bypass the multi-pass layout strategy
+            if (!string.IsNullOrEmpty(masterName))
+                return new ViewEngineResult(Enumerable.Empty<string>());
+
+            var bodyView = _viewEngines.FindPartialView(controllerContext, viewName);
+            var layoutView = _viewEngines.FindPartialView(controllerContext, "layout");
+            var documentView = _viewEngines.FindPartialView(controllerContext, "document");
+
+            if (bodyView.View == null ||
+                layoutView.View == null ||
+                documentView.View == null) {
+             
+                return new ViewEngineResult(
+                    (bodyView.SearchedLocations ?? Enumerable.Empty<string>())
+                        .Concat((layoutView.SearchedLocations ?? Enumerable.Empty<string>()))
+                        .Concat((documentView.SearchedLocations ?? Enumerable.Empty<string>()))
+                    );
+            }
+
+            var view = new LayoutView(new[] {
+                                                bodyView.View,
+                                                layoutView.View,
+                                                documentView.View,
+                                            });
+
+            return new ViewEngineResult(view, this);
+        }
+
+        public void ReleaseView(ControllerContext controllerContext, IView view) {
+
+        }
+    }
+
+
+}

src/Orchard/Mvc/ViewEngines/OrchardLayoutContext.cs

@@ -0,0 +1,25 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Web;
+using System.Web.Mvc;
+
+namespace Orchard.Mvc.ViewEngines {
+    public class OrchardLayoutContext {
+        private static readonly object _key = typeof(OrchardLayoutContext);
+
+        public string BodyContent { get; set; }
+
+        public static OrchardLayoutContext From(ControllerContext context) {
+            return From(context.HttpContext);
+        }
+
+        public static OrchardLayoutContext From(HttpContextBase context) {
+            if (context.Items.Contains(_key)) {
+                context.Items.Add(_key, new OrchardLayoutContext());
+            }
+            return (OrchardLayoutContext)context.Items[_key];
+        }
+    }
+}

src/Orchard/Orchard.csproj

@@ -200,6 +200,7 @@
     <Compile Include="Mvc\Html\ContentItemExtensions.cs" />
     <Compile Include="Mvc\Html\ItemDisplayExtensions.cs" />
     <Compile Include="Mvc\Html\ItemEditorExtensions.cs" />
+    <Compile Include="Mvc\Html\LayoutHelperExtensions.cs" />
     <Compile Include="Mvc\Html\MvcFormAntiForgeryPost.cs" />
     <Compile Include="Mvc\MvcModule.cs" />
     <Compile Include="Mvc\Html\HtmlHelperExtensions.cs" />
@@ -213,6 +214,9 @@
     <Compile Include="Mvc\Results\NotFoundResult.cs" />
     <Compile Include="Mvc\OrchardControllerIdentificationStrategy.cs" />
     <Compile Include="Mvc\Routes\RouteExtensions.cs" />
+    <Compile Include="Mvc\ViewEngines\LayoutView.cs" />
+    <Compile Include="Mvc\ViewEngines\LayoutViewEngine.cs" />
+    <Compile Include="Mvc\ViewEngines\OrchardLayoutContext.cs" />
     <Compile Include="Mvc\ViewModels\AdminViewModel.cs" />
     <Compile Include="Mvc\ViewModels\BaseViewModel.cs" />
     <Compile Include="Mvc\ViewPage.cs">