Merge branch '1.9.x' into dev

Conflicts:
	src/Orchard.Web/Modules/Orchard.Autoroute/Drivers/AutoroutePartDriver.cs
	src/Orchard.Web/Modules/Orchard.Autoroute/Migrations.cs
	src/Orchard.Web/Modules/Orchard.Search/Drivers/AdminSearchSettingsPartDriver.cs
	src/Orchard/Environment/DefaultOrchardShell.cs
	src/Orchard/Mvc/HttpContextAccessor.cs
	src/Orchard/Orchard.Framework.csproj
	src/Orchard/Tasks/BackgroundService.cs

src/Orchard.Tests.Modules/Indexing/LuceneIndexProviderTests.cs

@@ -303,5 +303,24 @@ namespace Orchard.Tests.Modules.Indexing {
             _provider.Store("default", _provider.New(1).Add("field", "value2"));
             Assert.That(searchBuilder.WithField("id", "1").Count(), Is.EqualTo(1));
         }
+
+        [Test]
+        public void IndexProviderShouldDeleteMoreThanMaxTermsCount() {
+            _provider.CreateIndex("default");
+
+            var documents = Enumerable.Range(1, 1025).Select(i => _provider.New(i).Add("field", "value1"));
+            _provider.Store("default", documents);
+            
+            var searchBuilder = _provider.CreateSearchBuilder("default");
+
+            Assert.That(searchBuilder.Count(), Is.EqualTo(1025));
+            Assert.That(searchBuilder.Get(1).ContentItemId, Is.EqualTo(1));
+            Assert.That(searchBuilder.Get(1025).ContentItemId, Is.EqualTo(1025));
+
+            _provider.Delete("default", Enumerable.Range(1, 1025));
+
+
+            Assert.That(searchBuilder.Count(), Is.EqualTo(0));
+        }
     }
 }

src/Orchard.Tests/Environment/DefaultWorkContextAccessorTests.cs

@@ -28,13 +28,6 @@ namespace Orchard.Tests.Environment {
             container.Mock<IHttpContextAccessor>()
                 .Setup(x => x.Current())
                 .Returns(() => _httpContextCurrent);
-
-            container.Mock<IHttpContextAccessor>()
-                .Setup(x => x.CreateContext(It.IsAny<ILifetimeScope>()))
-                .Returns(() => new StubHttpContext());
-
-            container.Mock<IWorkContextEvents>()
-                .Setup(x => x.Started());
         }
 
         [Test]

src/Orchard.Tests/Environment/ShellBuilders/DefaultShellContextFactoryTests.cs

@@ -56,11 +56,7 @@ namespace Orchard.Tests.Environment.ShellBuilders {
 
             _container.Mock<IHttpContextAccessor>()
                 .Setup(x => x.Current())
-                .Returns(httpContext);
-
-            _container.Mock<IHttpContextAccessor>()
-                .Setup(x => x.CreateContext(It.IsAny<ILifetimeScope>()))
-                .Returns(httpContext);
+                .Returns(default(HttpContextBase));
 
             var factory = _container.Resolve<IShellContextFactory>();
 

src/Orchard.Tests/Environment/State/DefaultProcessingEngineTests.cs

@@ -43,10 +43,6 @@ namespace Orchard.Tests.Environment.State {
             _container.Mock<IHttpContextAccessor>()
                 .Setup(x=>x.Current())
                 .Returns(httpContext);
-            _container.Mock<IHttpContextAccessor>()
-                .Setup(x => x.CreateContext(It.IsAny<ILifetimeScope>()))
-                .Returns(httpContext);
-
         }
 
         [TearDown]

src/Orchard.Tests/Stubs/StubHttpContextAccessor.cs

@@ -1,5 +1,4 @@
 using System.Web;
-using Autofac;
 using Orchard.Mvc;
 
 namespace Orchard.Tests.Stubs {
@@ -17,10 +16,6 @@ namespace Orchard.Tests.Stubs {
             return _httpContext;
         }
 
-        public HttpContextBase CreateContext(ILifetimeScope lifetimeScope) {
-            return _httpContext;
-        }
-
         public void Set(HttpContextBase httpContext) {
             _httpContext = httpContext;
         }

src/Orchard.Tests/Tasks/SweepGeneratorTests.cs

@@ -23,10 +23,6 @@ namespace Orchard.Tests.Tasks {
                 .Setup(x => x.Current())
                 .Returns(() => null);
 
-            container.Mock<IHttpContextAccessor>()
-                .Setup(x => x.CreateContext(It.IsAny<ILifetimeScope>()))
-                .Returns(() => new StubHttpContext());
-
             container.Mock<IWorkContextEvents>()
                 .Setup(x => x.Started());
         }

src/Orchard.Web/Core/Common/Drivers/BodyPartDriver.cs

@@ -61,10 +61,14 @@ namespace Orchard.Core.Common.Drivers {
         }
 
         protected override void Importing(BodyPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var importedText = context.Attribute(part.PartDefinition.Name, "Text");
-            if (importedText != null) {
-                part.Text = importedText;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Text", importedText =>
+                part.Text = importedText
+            );
         }
 
         protected override void Exporting(BodyPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Core/Common/Drivers/CommonPartDriver.cs

@@ -68,35 +68,35 @@ namespace Orchard.Core.Common.Drivers {
         }
 
         protected override void Importing(CommonPart part, ImportContentContext context) {
-            var owner = context.Attribute(part.PartDefinition.Name, "Owner");
-            if (owner != null) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Owner", owner => {
                 var contentIdentity = new ContentIdentity(owner);
-                part.Owner = _membershipService.GetUser(contentIdentity.Get("User.UserName"));
-            }
-            // use the super user if the referenced one doesn't exist
-            else {
-                part.Owner = _membershipService.GetUser(Services.WorkContext.CurrentSite.SuperUser);
-            }
 
-            var container = context.Attribute(part.PartDefinition.Name, "Container");
-            if (container != null) {
-                part.Container = context.GetItemFromSession(container);
-            }
+                // use the super user if the referenced one doesn't exist;
+                part.Owner =
+                    _membershipService.GetUser(contentIdentity.Get("User.UserName"))
+                    ?? _membershipService.GetUser(Services.WorkContext.CurrentSite.SuperUser);
+            });
 
-            var createdUtc = context.Attribute(part.PartDefinition.Name, "CreatedUtc");
-            if (createdUtc != null) {
-                part.CreatedUtc = XmlConvert.ToDateTime(createdUtc, XmlDateTimeSerializationMode.Utc);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Container", container =>
+                part.Container = context.GetItemFromSession(container)
+            );
 
-            var publishedUtc = context.Attribute(part.PartDefinition.Name, "PublishedUtc");
-            if (publishedUtc != null) {
-                part.PublishedUtc = XmlConvert.ToDateTime(publishedUtc, XmlDateTimeSerializationMode.Utc);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CreatedUtc", createdUtc =>
+                part.CreatedUtc = XmlConvert.ToDateTime(createdUtc, XmlDateTimeSerializationMode.Utc)
+            );
 
-            var modifiedUtc = context.Attribute(part.PartDefinition.Name, "ModifiedUtc");
-            if (modifiedUtc != null) {
-                part.ModifiedUtc = XmlConvert.ToDateTime(modifiedUtc, XmlDateTimeSerializationMode.Utc);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "PublishedUtc", publishedUtc =>
+                part.PublishedUtc = XmlConvert.ToDateTime(publishedUtc, XmlDateTimeSerializationMode.Utc)
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "ModifiedUtc", modifiedUtc =>
+                part.ModifiedUtc = XmlConvert.ToDateTime(modifiedUtc, XmlDateTimeSerializationMode.Utc)
+            );
         }
 
         protected override void Exporting(CommonPart part, ExportContentContext context) {

src/Orchard.Web/Core/Common/Drivers/IdentityPartDriver.cs

@@ -15,10 +15,14 @@ namespace Orchard.Core.Common.Drivers {
         }
 
         protected override void Importing(IdentityPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var identity = context.Attribute(part.PartDefinition.Name, "Identifier");
-            if (identity != null) {
-                part.Identifier = identity;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Identifier", identity =>
+                part.Identifier = identity
+            );
         }
 
         protected override void Exporting(IdentityPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Core/Containers/Drivers/ContainablePartDriver.cs

@@ -82,6 +82,11 @@ namespace Orchard.Core.Containers.Drivers {
         }
 
         protected override void Importing(ContainablePart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             context.ImportAttribute(part.PartDefinition.Name, "Position", s => part.Position = XmlConvert.ToInt32(s));
         }
 

src/Orchard.Web/Core/Containers/Drivers/ContainerPartDriver.cs

@@ -129,12 +129,16 @@ namespace Orchard.Core.Containers.Drivers {
         }
 
         protected override void Importing(ContainerPart part, ImportContentContext context) {
-            var itemContentType = context.Attribute(part.PartDefinition.Name, "ItemContentTypes");
-            if (itemContentType != null) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "ItemContentTypes", itemContentType => {
                 if (_contentDefinitionManager.GetTypeDefinition(itemContentType) != null) {
                     part.Record.ItemContentTypes = itemContentType;
                 }
-            }
+            });
 
             context.ImportAttribute(part.PartDefinition.Name, "ItemsShown", s => part.ItemsShown = XmlConvert.ToBoolean(s));
             context.ImportAttribute(part.PartDefinition.Name, "Paginated", s => part.Paginated = XmlConvert.ToBoolean(s));

src/Orchard.Web/Core/Containers/Drivers/ContainerWidgetPartDriver.cs

@@ -81,23 +81,25 @@ namespace Orchard.Core.Containers.Drivers {
         }
 
         protected override void Importing(ContainerWidgetPart part, ImportContentContext context) {
-            var containerIdentity = context.Attribute(part.PartDefinition.Name, "Container");
-            if (containerIdentity != null) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Container", containerIdentity => {
                 var container = context.GetItemFromSession(containerIdentity);
                 if (container != null) {
                     part.Record.ContainerId = container.Id;
                 }
-            }
+            });
 
-            var pageSize = context.Attribute(part.PartDefinition.Name, "PageSize");
-            if (pageSize != null) {
-                part.Record.PageSize = Convert.ToInt32(pageSize);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "PageSize", pageSize =>
+                part.Record.PageSize = Convert.ToInt32(pageSize)
+            );
 
-            var filterByValue = context.Attribute(part.PartDefinition.Name, "FilterByValue");
-            if (filterByValue != null) {
-                part.Record.FilterByValue = filterByValue;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "FilterByValue", filterByValue =>
+                part.Record.FilterByValue = filterByValue
+            );
         }
 
         protected override void Exporting(ContainerWidgetPart part, ExportContentContext context) {

src/Orchard.Web/Core/Containers/Drivers/CustomPropertiesDriver.cs

@@ -24,20 +24,22 @@ namespace Orchard.Core.Containers.Drivers {
         }
 
         protected override void Importing(CustomPropertiesPart part, ImportContentContext context) {
-            var customOne = context.Attribute(part.PartDefinition.Name, "CustomOne");
-            if (customOne != null) {
-                part.Record.CustomOne = customOne;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var customTwo = context.Attribute(part.PartDefinition.Name, "CustomTwo");
-            if (customTwo != null) {
-                part.Record.CustomTwo = customTwo;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CustomOne", customOne =>
+                part.Record.CustomOne = customOne
+            );
 
-            var customThree = context.Attribute(part.PartDefinition.Name, "CustomThree");
-            if (customThree != null) {
-                part.Record.CustomThree = customThree;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CustomTwo", customTwo =>
+                part.Record.CustomTwo = customTwo
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "CustomThree", customThree =>
+                part.Record.CustomThree = customThree
+            );
         }
 
         protected override void Exporting(CustomPropertiesPart part, ExportContentContext context) {

src/Orchard.Web/Core/Navigation/Drivers/AdminMenuPartDriver.cs

@@ -71,20 +71,22 @@ namespace Orchard.Core.Navigation.Drivers {
         }
 
         protected override void Importing(AdminMenuPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var adminMenuText = context.Attribute(part.PartDefinition.Name, "AdminMenuText");
-            if (adminMenuText != null) {
-                part.AdminMenuText = adminMenuText;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var position = context.Attribute(part.PartDefinition.Name, "AdminMenuPosition");
-            if (position != null) {
-                part.AdminMenuPosition = position;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "AdminMenuText", adminMenuText =>
+                part.AdminMenuText = adminMenuText
+            );
 
-            var onAdminMenu = context.Attribute(part.PartDefinition.Name, "OnAdminMenu");
-            if (onAdminMenu != null) {
-                part.OnAdminMenu = Convert.ToBoolean(onAdminMenu);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "AdminMenuPosition", position =>
+                part.AdminMenuPosition = position
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "OnAdminMenu", onAdminMenu =>
+                part.OnAdminMenu = Convert.ToBoolean(onAdminMenu)
+            );
         }
 
         protected override void Exporting(AdminMenuPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Core/Navigation/Drivers/MenuItemPartDriver.cs

@@ -35,10 +35,14 @@ namespace Orchard.Core.Navigation.Drivers {
         }
 
         protected override void Importing(MenuItemPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var url = context.Attribute(part.PartDefinition.Name, "Url");
-            if (url != null) {
-                part.Url = url;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Url", url =>
+                part.Url = url
+            );
         }
 
         protected override void Exporting(MenuItemPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Core/Navigation/Drivers/MenuPartDriver.cs

@@ -80,23 +80,25 @@ namespace Orchard.Core.Navigation.Drivers {
         }
 
         protected override void Importing(MenuPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var menuText = context.Attribute(part.PartDefinition.Name, "MenuText");
-            if (menuText != null) {
-                part.MenuText = menuText;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var position = context.Attribute(part.PartDefinition.Name, "MenuPosition");
-            if (position != null) {
-                part.MenuPosition = position;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "MenuText", menuText =>
+                part.MenuText = menuText
+            );
 
-            var menuIdentity = context.Attribute(part.PartDefinition.Name, "Menu");
-            if (menuIdentity != null) {
+            context.ImportAttribute(part.PartDefinition.Name, "MenuPosition", position =>
+                part.MenuPosition = position
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "Menu", menuIdentity => {
                 var menu = context.GetItemFromSession(menuIdentity);
                 if (menu != null) {
                     part.Menu = menu;
                 }
-            }
+            });
         }
 
         protected override void Exporting(MenuPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Core/Navigation/Drivers/MenuWidgetPartDriver.cs

@@ -190,6 +190,11 @@ namespace Orchard.Core.Navigation.Drivers {
         }
 
         protected override void Importing(MenuWidgetPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             context.ImportAttribute(part.PartDefinition.Name, "StartLevel", x => part.StartLevel = Convert.ToInt32(x));
             context.ImportAttribute(part.PartDefinition.Name, "Levels", x => part.Levels = Convert.ToInt32(x));
             context.ImportAttribute(part.PartDefinition.Name, "Breadcrumb", x => part.Breadcrumb = Convert.ToBoolean(x));

src/Orchard.Web/Core/Navigation/Drivers/ShapeMenuItemPartDriver.cs

@@ -37,13 +37,12 @@ namespace Orchard.Core.Navigation.Drivers {
         }
 
         protected override void Importing(ShapeMenuItemPart part, ImportContentContext context) {
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "ShapeType"), x => part.ShapeType = x);
-        }
-
-        private static void IfNotNull<T>(T value, Action<T> then) where T : class {
-            if(value != null) {
-                then(value);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "ShapeType", x => part.ShapeType = x);
         }
 
         protected override void Exporting(ShapeMenuItemPart part, ExportContentContext context) {

src/Orchard.Web/Core/Settings/Drivers/SiteSettingsPartDriver.cs

@@ -116,12 +116,16 @@ namespace Orchard.Core.Settings.Drivers {
         }
 
         protected override void Importing(SiteSettingsPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var supportedCultures = context.Attribute(part.PartDefinition.Name, "SupportedCultures");
-            if (supportedCultures != null) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "SupportedCultures", supportedCultures => {
                 foreach (var culture in supportedCultures.Split(';')) {
                     _cultureManager.AddCulture(culture);
                 }
-            }
+            });
         }
     }
 }

src/Orchard.Web/Core/Title/Drivers/TitlePartDriver.cs

@@ -39,10 +39,14 @@ namespace Orchard.Core.Title.Drivers {
         }
 
         protected override void Importing(TitlePart part, ImportContentContext context) {
-            var title = context.Attribute(part.PartDefinition.Name, "Title");
-            if (title != null) {
-                part.Title = title;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Title", title =>
+                part.Title = title
+            );
         }
 
         protected override void Exporting(TitlePart part, ExportContentContext context) {

src/Orchard.Web/Modules/Lucene/Services/LuceneIndexProvider.cs

@@ -29,7 +29,8 @@ namespace Lucene.Services {
 
         public static readonly Version LuceneVersion = Version.LUCENE_29;
         public static readonly DateTime DefaultMinDateTime = new DateTime(1980, 1, 1);
-        
+        public static readonly int BatchSize = BooleanQuery.MaxClauseCount;
+
         public LuceneIndexProvider(
             IAppDataFolder appDataFolder, 
             ShellSettings shellSettings,
@@ -152,17 +153,25 @@ namespace Lucene.Services {
             }
 
             using (var writer = new IndexWriter(GetDirectory(indexName), _analyzerProvider.GetAnalyzer(indexName), false, IndexWriter.MaxFieldLength.UNLIMITED)) {
-                var query = new BooleanQuery();
+                // Process documents by batch as there is a max number of terms a query can contain (1024 by default).
+                var pageCount = documentIds.Count() / BatchSize + 1;
+                for (int page = 0; page < pageCount; page++) {
+                    var query = new BooleanQuery();
 
-                try {
-                    foreach (var id in documentIds) {
-                        query.Add(new BooleanClause(new TermQuery(new Term("id", id.ToString(CultureInfo.InvariantCulture))), Occur.SHOULD));
+                    try {
+                        var batch = documentIds
+                            .Skip(page * BatchSize)
+                            .Take(BatchSize);
+
+                        foreach (var id in batch) {
+                            query.Add(new BooleanClause(new TermQuery(new Term("id", id.ToString(CultureInfo.InvariantCulture))), Occur.SHOULD));
+                        }
+
+                        writer.DeleteDocuments(query);
+                    }
+                    catch (Exception ex) {
+                        Logger.Error(ex, "An unexpected error occured while removing the documents [{0}] from the index [{1}].", String.Join(", ", documentIds), indexName);
                     }
-
-                    writer.DeleteDocuments(query);
-                }
-                catch (Exception ex) {
-                    Logger.Error(ex, "An unexpected error occured while removing the documents [{0}] from the index [{1}].", String.Join(", ", documentIds), indexName);
                 }
             }
         }

src/Orchard.Web/Modules/Orchard.Alias/Implementation/Updater/AliasHolderUpdaterTask.cs

@@ -1,7 +1,4 @@
 using System;
-using System.Linq;
-using Orchard.Alias.Implementation.Holder;
-using Orchard.Alias.Implementation.Storage;
 using Orchard.Environment;
 using Orchard.Tasks;
 using Orchard.Logging;

src/Orchard.Web/Modules/Orchard.AntiSpam/Drivers/SpamFilterPartDriver.cs

@@ -42,6 +42,11 @@ namespace Orchard.AntiSpam.Drivers {
         }
 
         protected override void Importing(SpamFilterPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var status = context.Attribute(part.PartDefinition.Name, "Status");
             
             if (status != null) {

src/Orchard.Web/Modules/Orchard.ArchiveLater/Drivers/ArchiveLaterPartDriver.cs

@@ -92,10 +92,14 @@ namespace Orchard.ArchiveLater.Drivers {
         }
 
         protected override void Importing(ArchiveLaterPart part, ImportContentContext context) {
-            var scheduledUtc = context.Attribute(part.PartDefinition.Name, "ScheduledArchiveUtc");
-            if (scheduledUtc != null) {
-                part.ScheduledArchiveUtc.Value = XmlConvert.ToDateTime(scheduledUtc, XmlDateTimeSerializationMode.Utc);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "ScheduledArchiveUtc", scheduledUtc =>
+                part.ScheduledArchiveUtc.Value = XmlConvert.ToDateTime(scheduledUtc, XmlDateTimeSerializationMode.Utc)
+            );
         }
 
         protected override void Exporting(ArchiveLaterPart part, ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Autoroute/Drivers/AutoroutePartDriver.cs

@@ -154,6 +154,11 @@ namespace Orchard.Autoroute.Drivers {
         }
 
         protected override void Importing(AutoroutePart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             context.ImportAttribute(part.PartDefinition.Name, "Alias", s => part.DisplayAlias = s);
             context.ImportAttribute(part.PartDefinition.Name, "CustomPattern", s => part.CustomPattern = s);
             context.ImportAttribute(part.PartDefinition.Name, "UseCustomPattern", s => part.UseCustomPattern = XmlHelper.Parse<bool>(s));

src/Orchard.Web/Modules/Orchard.Autoroute/Migrations.cs

@@ -1,4 +1,5 @@
 using Orchard.Autoroute.Models;
+using Orchard.ContentManagement;
 using Orchard.Autoroute.Services;
 using Orchard.Autoroute.Settings;
 using Orchard.ContentManagement;

src/Orchard.Web/Modules/Orchard.Blogs/Drivers/BlogArchivesPartDriver.cs

@@ -53,10 +53,14 @@ namespace Orchard.Blogs.Drivers {
         }
 
         protected override void Importing(BlogArchivesPart part, ImportContentContext context) {
-            var blog = context.Attribute(part.PartDefinition.Name, "Blog");
-            if (blog != null) {
-                part.BlogId = context.GetItemFromSession(blog).Id;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Blog", blog =>
+                part.BlogId = context.GetItemFromSession(blog).Id
+            );
         }
 
         protected override void Exporting(BlogArchivesPart part, ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Blogs/Drivers/BlogPartDriver.cs

@@ -43,20 +43,22 @@ namespace Orchard.Blogs.Drivers {
         }
 
         protected override void Importing(BlogPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var description = context.Attribute(part.PartDefinition.Name, "Description");
-            if (description != null) {
-                part.Description = description;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var postCount = context.Attribute(part.PartDefinition.Name, "PostCount");
-            if (postCount != null) {
-                part.PostCount = Convert.ToInt32(postCount);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Description", description =>
+                part.Description = description
+            );
 
-            var feedProxyUrl = context.Attribute(part.PartDefinition.Name, "FeedProxyUrl");
-            if (feedProxyUrl != null) {
-                part.FeedProxyUrl = feedProxyUrl;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "PostCount", postCount =>
+                part.PostCount = Convert.ToInt32(postCount)
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "FeedProxyUrl", feedProxyUrl =>
+                part.FeedProxyUrl = feedProxyUrl
+            );
         }
 
         protected override void Exporting(BlogPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Blogs/Drivers/RecentBlogPostsPartDriver.cs

@@ -66,22 +66,25 @@ namespace Orchard.Blogs.Drivers {
         }
 
         protected override void Importing(RecentBlogPostsPart part, ImportContentContext context) {
-            var blog = context.Attribute(part.PartDefinition.Name, "Blog");
-            if (blog != null) {
-                part.BlogId = context.GetItemFromSession(blog).Id;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var count = context.Attribute(part.PartDefinition.Name, "Count");
-            if (count != null) {
-                part.Count = Convert.ToInt32(count);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Blog", blog =>
+                part.BlogId = context.GetItemFromSession(blog).Id
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "Count", count =>
+               part.Count = Convert.ToInt32(count)
+            );
         }
 
         protected override void Exporting(RecentBlogPostsPart part, ExportContentContext context) {
             var blog = _contentManager.Get(part.BlogId);
             var blogIdentity = _contentManager.GetItemMetadata(blog).Identity;
-            context.Element(part.PartDefinition.Name).SetAttributeValue("Blog", blogIdentity);
 
+            context.Element(part.PartDefinition.Name).SetAttributeValue("Blog", blogIdentity);
             context.Element(part.PartDefinition.Name).SetAttributeValue("Count", part.Count);
         }
     }

src/Orchard.Web/Modules/Orchard.Comments/Drivers/CommentPartDriver.cs

@@ -132,71 +132,65 @@ namespace Orchard.Comments.Drivers {
         }
 
         protected override void Importing(CommentPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var author = context.Attribute(part.PartDefinition.Name, "Author");
-            if (author != null) {
-                part.Record.Author = author;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var siteName = context.Attribute(part.PartDefinition.Name, "SiteName");
-            if (siteName != null) {
-                part.Record.SiteName = siteName;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Author", author =>
+                part.Record.Author = author
+            );
 
-            var userName = context.Attribute(part.PartDefinition.Name, "UserName");
-            if (userName != null) {
-                part.Record.UserName = userName;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "SiteName", siteName =>
+                part.Record.SiteName = siteName
+            );
 
-            var email = context.Attribute(part.PartDefinition.Name, "Email");
-            if (email != null) {
-                part.Record.Email = email;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "UserName", userName =>
+                part.Record.UserName = userName
+            );
 
-            var position = context.Attribute(part.PartDefinition.Name, "Position");
-            if (position != null) {
-                part.Record.Position = decimal.Parse(position, CultureInfo.InvariantCulture);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Email", email =>
+                part.Record.Email = email
+            );
 
-            var status = context.Attribute(part.PartDefinition.Name, "Status");
-            if (status != null) {
-                part.Record.Status = (CommentStatus)Enum.Parse(typeof(CommentStatus), status);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Position", position =>
+                part.Record.Position = decimal.Parse(position, CultureInfo.InvariantCulture)
+            );
 
-            var commentDate = context.Attribute(part.PartDefinition.Name, "CommentDateUtc");
-            if (commentDate != null) {
-                part.Record.CommentDateUtc = XmlConvert.ToDateTime(commentDate, XmlDateTimeSerializationMode.Utc);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Status", status =>
+                part.Record.Status = (CommentStatus)Enum.Parse(typeof(CommentStatus), status)
+            );
 
-            var text = context.Attribute(part.PartDefinition.Name, "CommentText");
-            if (text != null) {
-                part.Record.CommentText = text;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CommentDateUtc", commentDate =>
+                part.Record.CommentDateUtc = XmlConvert.ToDateTime(commentDate, XmlDateTimeSerializationMode.Utc)
+            );
 
-            var commentedOn = context.Attribute(part.PartDefinition.Name, "CommentedOn");
-            if (commentedOn != null) {
+            context.ImportAttribute(part.PartDefinition.Name, "CommentText", text =>
+                part.Record.CommentText = text
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "CommentedOn", commentedOn => {
                 var contentItem = context.GetItemFromSession(commentedOn);
                 if (contentItem != null) {
                     part.Record.CommentedOn = contentItem.Id;
                 }
 
                 contentItem.As<CommentsPart>().Record.CommentPartRecords.Add(part.Record);
-            }
+            });
 
-            var repliedOn = context.Attribute(part.PartDefinition.Name, "RepliedOn");
-            if (repliedOn != null) {
+            context.ImportAttribute(part.PartDefinition.Name, "RepliedOn", repliedOn => {
                 var contentItem = context.GetItemFromSession(repliedOn);
                 if (contentItem != null) {
                     part.Record.RepliedOn = contentItem.Id;
                 }
-            }
+            });
 
-            var commentedOnContainer = context.Attribute(part.PartDefinition.Name, "CommentedOnContainer");
-            if (commentedOnContainer != null) {
+            context.ImportAttribute(part.PartDefinition.Name, "CommentedOnContainer", commentedOnContainer => {
                 var container = context.GetItemFromSession(commentedOnContainer);
                 if (container != null) {
                     part.Record.CommentedOnContainer = container.Id;
                 }
-            }
+            });
         }
 
         protected override void Exporting(CommentPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Comments/Drivers/CommentsPartDriver.cs

@@ -111,20 +111,22 @@ namespace Orchard.Comments.Drivers {
         }
 
         protected override void Importing(CommentsPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var commentsShown = context.Attribute(part.PartDefinition.Name, "CommentsShown");
-            if (commentsShown != null) {
-                part.CommentsShown = Convert.ToBoolean(commentsShown);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var commentsActive = context.Attribute(part.PartDefinition.Name, "CommentsActive");
-            if (commentsActive != null) {
-                part.CommentsActive = Convert.ToBoolean(commentsActive);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CommentsShown", commentsShown =>
+                part.CommentsShown = Convert.ToBoolean(commentsShown)
+            );
 
-            var threadedComments = context.Attribute(part.PartDefinition.Name, "ThreadedComments");
-            if (threadedComments != null) {
-                part.ThreadedComments = Convert.ToBoolean(threadedComments);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "CommentsActive", commentsActive =>
+                part.CommentsActive = Convert.ToBoolean(commentsActive)
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "ThreadedComments", threadedComments =>
+                part.ThreadedComments = Convert.ToBoolean(threadedComments)
+            );
         }
 
         protected override void Exporting(CommentsPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.ContentPermissions/Drivers/ContentPermissionsPartDriver.cs

@@ -162,6 +162,11 @@ namespace Orchard.ContentPermissions.Drivers {
         }
 
         protected override void Importing(ContentPermissionsPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             context.ImportAttribute(part.PartDefinition.Name, "Enabled", s => part.Enabled = XmlConvert.ToBoolean(s));
             context.ImportAttribute(part.PartDefinition.Name, "ViewContent", s => part.ViewContent = s);
             context.ImportAttribute(part.PartDefinition.Name, "EditContent", s => part.EditContent = s);

src/Orchard.Web/Modules/Orchard.ContentPicker/Drivers/ContentMenuItemPartDriver.cs

@@ -60,14 +60,18 @@ namespace Orchard.ContentPicker.Drivers {
         }
 
         protected override void Importing(ContentMenuItemPart part, ImportContentContext context) {
-            var contentItemId = context.Attribute(part.PartDefinition.Name, "ContentItem");
-            if (contentItemId != null) {
-                var contentItem = context.GetItemFromSession(contentItemId);
-                part.Content = contentItem;
-            }
-            else {
-                part.Content = null;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "ContentItem", 
+                contentItemId => {
+                    var contentItem = context.GetItemFromSession(contentItemId);
+                    part.Content = contentItem;
+                }, () => 
+                    part.Content = null
+            );
         }
 
         protected override void Exporting(ContentMenuItemPart part, ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.CustomForms/Drivers/CustomFormPartDriver.cs

@@ -59,21 +59,20 @@ namespace Orchard.CustomForms.Drivers {
         }
 
         protected override void Importing(CustomFormPart part, ImportContentContext context) {
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "ContentType"), x => part.Record.ContentType = x);
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "SaveContentItem"), x => part.Record.SaveContentItem = Boolean.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "CustomMessage"), x => part.Record.CustomMessage = Boolean.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Message"), x => part.Record.Message = x);
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Redirect"), x => part.Record.Redirect = Boolean.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "RedirectUrl"), x => part.Record.RedirectUrl = x);
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "SubmitButtonText"), x => part.Record.SubmitButtonText = x);
-        }
-
-        private static void IfNotNull<T>(T value, Action<T> then) {
-            if (value != null) {
-                then(value);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
-        }
 
+            context.ImportAttribute(part.PartDefinition.Name, "ContentType", x => part.Record.ContentType = x);
+            context.ImportAttribute(part.PartDefinition.Name, "SaveContentItem", x => part.Record.SaveContentItem = Boolean.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "CustomMessage", x => part.Record.CustomMessage = Boolean.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "Message", x => part.Record.Message = x);
+            context.ImportAttribute(part.PartDefinition.Name, "Redirect", x => part.Record.Redirect = Boolean.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "RedirectUrl", x => part.Record.RedirectUrl = x);
+            context.ImportAttribute(part.PartDefinition.Name, "SubmitButtonText", x => part.Record.SubmitButtonText = x);
+        }
+        
         protected override void Exporting(CustomFormPart part, ExportContentContext context) {
             context.Element(part.PartDefinition.Name).SetAttributeValue("ContentType", part.Record.ContentType);
             context.Element(part.PartDefinition.Name).SetAttributeValue("SaveContentItem", part.Record.SaveContentItem);

src/Orchard.Web/Modules/Orchard.Layouts/Drivers/LayoutPartDriver.cs

@@ -140,6 +140,11 @@ namespace Orchard.Layouts.Drivers {
         }
 
         protected override void Importing(LayoutPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             context.ImportChildEl(part.PartDefinition.Name, "LayoutData", s => {
                 part.LayoutData = s;
                 _layoutManager.Importing(new ImportLayoutContext {

src/Orchard.Web/Modules/Orchard.Layouts/Drivers/ProjectionElementDriver.cs

@@ -290,11 +290,11 @@ namespace Orchard.Layouts.Drivers {
             var query = element.QueryId != null ? _contentManager.Get<QueryPart>(element.QueryId.Value) : default(QueryPart);
             var layout = query != null && element.LayoutId != null ? _layoutRepository.Get(element.LayoutId.Value) : default(LayoutRecord);
             var queryIdentity = query != null ? _contentManager.GetItemMetadata(query).Identity.ToString() : default(string);
-            var layoutIndex = layout != null ? query.Layouts.IndexOf(layout) : default(int?);
+            var layoutIndex = layout != null ? query.Layouts.IndexOf(layout) : -1; // -1 is the Default Layout.
 
-            if (queryIdentity != null && layoutIndex != null) {
+            if (queryIdentity != null) {
                 context.ExportableData["QueryId"] = queryIdentity;
-                context.ExportableData["LayoutIndex"] = layoutIndex.Value.ToString();
+                context.ExportableData["LayoutIndex"] = layoutIndex.ToString();
             }
         }
 

src/Orchard.Web/Modules/Orchard.Layouts/Handlers/LayoutPartHandler.cs

@@ -16,7 +16,6 @@ namespace Orchard.Layouts.Handlers {
         private readonly IContentPartDisplay _contentPartDisplay;
         private readonly IShapeDisplay _shapeDisplay;
         private readonly ILayoutSerializer _serializer;
-        private readonly IStaticHttpContextScopeFactory _staticHttpContextScopeFactory;
         private readonly IAliasService _aliasService;
 
         public LayoutPartHandler(
@@ -26,7 +25,6 @@ namespace Orchard.Layouts.Handlers {
             IContentPartDisplay contentPartDisplay, 
             IShapeDisplay shapeDisplay, 
             ILayoutSerializer serializer,
-            IStaticHttpContextScopeFactory staticHttpContextScopeFactory,
             IAliasService aliasService) {
 
             _layoutManager = layoutManager;
@@ -34,7 +32,6 @@ namespace Orchard.Layouts.Handlers {
             _contentPartDisplay = contentPartDisplay;
             _shapeDisplay = shapeDisplay;
             _serializer = serializer;
-            _staticHttpContextScopeFactory = staticHttpContextScopeFactory;
             _aliasService = aliasService;
 
             Filters.Add(StorageFilter.For(repository));
@@ -44,22 +41,13 @@ namespace Orchard.Layouts.Handlers {
 
         private void IndexLayout(IndexContentContext context, LayoutPart part) {
             var layoutShape = _contentPartDisplay.BuildDisplay(part);
-            var layoutHtml = RenderShape(layoutShape);
+            var layoutHtml = _shapeDisplay.Display(layoutShape);
 
             context.DocumentIndex
                 .Add("body", layoutHtml).RemoveTags().Analyze()
                 .Add("format", "html").Store();
         }
 
-        /// <summary>
-        /// This method of rendering is safe even in background tasks.
-        /// </summary>
-        private string RenderShape(dynamic shape) {
-            using (_staticHttpContextScopeFactory.CreateStaticScope()) {
-                return _shapeDisplay.Display(shape);
-            }
-        }
-
         private void UpdateTemplateClients(PublishContentContext context, LayoutPart part) {
             UpdateTemplateClients(part);
         }

src/Orchard.Web/Modules/Orchard.Localization/Drivers/LocalizationPartDriver.cs

@@ -108,16 +108,19 @@ namespace Orchard.Localization.Drivers {
         }
 
         protected override void Importing(LocalizationPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var masterContentItem = context.Attribute(part.PartDefinition.Name, "MasterContentItem");
-            if (masterContentItem != null) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "MasterContentItem", masterContentItem => {
                 var contentItem = context.GetItemFromSession(masterContentItem);
                 if (contentItem != null) {
                     part.MasterContentItem = contentItem;
                 }
-            }
+            });
 
-            var culture = context.Attribute(part.PartDefinition.Name, "Culture");
-            if (culture != null) {
+            context.ImportAttribute(part.PartDefinition.Name, "Culture", culture => {
                 var targetCulture = _cultureManager.GetCultureByName(culture);
                 // Add Culture.
                 if (targetCulture == null && _cultureManager.IsValidCulture(culture)) {
@@ -125,7 +128,7 @@ namespace Orchard.Localization.Drivers {
                     targetCulture = _cultureManager.GetCultureByName(culture);
                 }
                 part.Culture = targetCulture;
-            }
+            });
         }
 
         protected override void Exporting(LocalizationPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/AudioPartDriver.cs

@@ -17,10 +17,14 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(AudioPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var length = context.Attribute(part.PartDefinition.Name, "Length");
-            if (length != null) {
-                part.Length = int.Parse(length);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Length", length =>
+                part.Length = int.Parse(length)
+            );
         }
     }
 }

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/DocumentPartDriver.cs

@@ -17,10 +17,14 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(DocumentPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var length = context.Attribute(part.PartDefinition.Name, "Length");
-            if (length != null) {
-                part.Length = int.Parse(length);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Length", length =>
+                part.Length = int.Parse(length)
+            );
         }
     }
 }

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/ImagePartDriver.cs

@@ -20,15 +20,18 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(ImagePart part, ContentManagement.Handlers.ImportContentContext context) {
-            var height = context.Attribute(part.PartDefinition.Name, "Height");
-            if (height != null) {
-                part.Height = int.Parse(height);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var width = context.Attribute(part.PartDefinition.Name, "Width");
-            if (width != null) {
-                part.Width = int.Parse(width);
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Height", height =>
+                part.Height = int.Parse(height)
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "Width", width =>
+                part.Width = int.Parse(width)
+            );
         }
     }
 }

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/MediaPartDriver.cs

@@ -36,30 +36,30 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(MediaPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var mimeType = context.Attribute(part.PartDefinition.Name, "MimeType");
-            if (mimeType != null) {
-                part.MimeType = mimeType;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
 
-            var caption = context.Attribute(part.PartDefinition.Name, "Caption");
-            if (caption != null) {
-                part.Caption = caption;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "MimeType", mimeType =>
+                part.MimeType = mimeType
+            );
 
-            var alternateText = context.Attribute(part.PartDefinition.Name, "AlternateText");
-            if (alternateText != null) {
-                part.AlternateText = alternateText;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "Caption", caption =>
+                part.Caption = caption
+            );
 
-            var folderPath = context.Attribute(part.PartDefinition.Name, "FolderPath");
-            if (folderPath != null) {
-                part.FolderPath = folderPath;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "AlternateText", alternateText =>
+                part.AlternateText = alternateText
+            );
 
-            var fileName = context.Attribute(part.PartDefinition.Name, "FileName");
-            if (fileName != null) {
-                part.FileName = fileName;
-            }
+            context.ImportAttribute(part.PartDefinition.Name, "FolderPath", folderPath =>
+                part.FolderPath = folderPath
+            );
+
+            context.ImportAttribute(part.PartDefinition.Name, "FileName", fileName =>
+                part.FileName = fileName
+            );
         }
 
         protected override void Exporting(MediaPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/OEmbedPartDriver.cs

@@ -17,10 +17,14 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(OEmbedPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var source = context.Attribute(part.PartDefinition.Name, "Source");
-            if (source != null) {
-                part.Source = source;
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Source", source =>
+                part.Source = source
+            );
         }
     }
 }

src/Orchard.Web/Modules/Orchard.MediaLibrary/Drivers/VideoPartDriver.cs

@@ -17,10 +17,14 @@ namespace Orchard.MediaLibrary.Drivers {
         }
 
         protected override void Importing(VideoPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var length = context.Attribute(part.PartDefinition.Name, "Length");
-            if (length != null) {
-                part.Length = int.Parse(length);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Length", length =>
+                part.Length = int.Parse(length)
+            );
         }
     }
 }

src/Orchard.Web/Modules/Orchard.MediaProcessing/Drivers/ImageProfilePartDriver.cs

@@ -85,6 +85,11 @@ namespace Orchard.MediaProcessing.Drivers {
         }
 
         protected override void Importing(ImageProfilePart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var element = context.Data.Element(part.PartDefinition.Name);
 
             part.Name = element.Attribute("Name").Value;

src/Orchard.Web/Modules/Orchard.Projections/Drivers/NavigationQueryPartDriver.cs

@@ -54,8 +54,13 @@ namespace Orchard.Projections.Drivers {
         }
 
         protected override void Importing(NavigationQueryPart part, ImportContentContext context) {
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Items"), x => part.Record.Items = Int32.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Offset"), x => part.Record.Skip = Int32.Parse(x));
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Items", x => part.Record.Items = Int32.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "Offset", x => part.Record.Skip = Int32.Parse(x));
         }
 
         protected override void Imported(NavigationQueryPart part, ImportContentContext context) {
@@ -65,13 +70,7 @@ namespace Orchard.Projections.Drivers {
                 part.Record.QueryPartRecord = context.GetItemFromSession(query).As<QueryPart>().Record;
             }
         }
-
-        private static void IfNotNull<T>(T value, Action<T> then) where T : class {
-            if(value != null) {
-                then(value);
-            }
-        }
-
+        
         protected override void Exporting(NavigationQueryPart part, ExportContentContext context) {
             context.Element(part.PartDefinition.Name).SetAttributeValue("Items", part.Record.Items);
             context.Element(part.PartDefinition.Name).SetAttributeValue("Offset", part.Record.Skip);

src/Orchard.Web/Modules/Orchard.Projections/Drivers/ProjectionPartDriver.cs

@@ -294,12 +294,17 @@ namespace Orchard.Projections.Drivers {
         }
 
         protected override void Importing(ProjectionPart part, ImportContentContext context) {
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Items"), x => part.Record.Items = Int32.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "ItemsPerPage"), x => part.Record.ItemsPerPage = Int32.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "Offset"), x => part.Record.Skip = Int32.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "PagerSuffix"), x => part.Record.PagerSuffix = x);
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "MaxItems"), x => part.Record.MaxItems = Int32.Parse(x));
-            IfNotNull(context.Attribute(part.PartDefinition.Name, "DisplayPager"), x => part.Record.DisplayPager = Boolean.Parse(x));
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "Items", x => part.Record.Items = Int32.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "ItemsPerPage", x => part.Record.ItemsPerPage = Int32.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "Offset", x => part.Record.Skip = Int32.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "PagerSuffix", x => part.Record.PagerSuffix = x);
+            context.ImportAttribute(part.PartDefinition.Name, "MaxItems", x => part.Record.MaxItems = Int32.Parse(x));
+            context.ImportAttribute(part.PartDefinition.Name, "DisplayPager", x => part.Record.DisplayPager = Boolean.Parse(x));
         }
 
         protected override void Imported(ProjectionPart part, ImportContentContext context) {
@@ -318,13 +323,7 @@ namespace Orchard.Projections.Drivers {
                 }
             }
         }
-
-        private static void IfNotNull<T>(T value, Action<T> then) {
-            if(value != null) {
-                then(value);
-            }
-        }
-
+        
         protected override void Exporting(ProjectionPart part, ExportContentContext context) {
             context.Element(part.PartDefinition.Name).SetAttributeValue("Items", part.Record.Items);
             context.Element(part.PartDefinition.Name).SetAttributeValue("ItemsPerPage", part.Record.ItemsPerPage);

src/Orchard.Web/Modules/Orchard.Projections/Drivers/QueryPartDriver.cs

@@ -103,6 +103,11 @@ namespace Orchard.Projections.Drivers {
         }
 
         protected override void Importing(QueryPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var queryElement = context.Data.Element(part.PartDefinition.Name);
 
             part.Record.FilterGroups.Clear();

src/Orchard.Web/Modules/Orchard.PublishLater/Drivers/PublishLaterPartDriver.cs

@@ -110,10 +110,14 @@ namespace Orchard.PublishLater.Drivers {
         }
 
         protected override void Importing(PublishLaterPart part, ImportContentContext context) {
-            var scheduledUtc = context.Attribute(part.PartDefinition.Name, "ScheduledPublishUtc");
-            if (scheduledUtc != null) {
-                part.ScheduledPublishUtc.Value = XmlConvert.ToDateTime(scheduledUtc, XmlDateTimeSerializationMode.Utc);
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "ScheduledPublishUtc", scheduledUtc =>
+                part.ScheduledPublishUtc.Value = XmlConvert.ToDateTime(scheduledUtc, XmlDateTimeSerializationMode.Utc)
+            );
         }
 
         protected override void Exporting(PublishLaterPart part, ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Roles/Drivers/UserRolesPartDriver.cs

@@ -96,29 +96,32 @@ namespace Orchard.Roles.Drivers {
         }
 
         protected override void Importing(UserRolesPart part, ContentManagement.Handlers.ImportContentContext context) {
-            var roles = context.Attribute(part.PartDefinition.Name, "Roles");
-            if(string.IsNullOrEmpty(roles)) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
                 return;
             }
 
-            var userRoles = roles.Split(new[] {','}, StringSplitOptions.RemoveEmptyEntries);
+            context.ImportAttribute(part.PartDefinition.Name, "Roles", roles => {
 
-            // create new roles
-            foreach (var role in userRoles) {
-                var roleRecord = _roleService.GetRoleByName(role);
+                var userRoles = roles.Split(new[] { ',' }, StringSplitOptions.RemoveEmptyEntries);
 
-                // create the role if it doesn't already exist
-                if (roleRecord == null) {
-                    _roleService.CreateRole(role);
+                // create new roles
+                foreach (var role in userRoles) {
+                    var roleRecord = _roleService.GetRoleByName(role);
+
+                    // create the role if it doesn't already exist
+                    if (roleRecord == null) {
+                        _roleService.CreateRole(role);
+                    }
                 }
-            }
 
-            var currentUserRoleRecords = _userRolesRepository.Fetch(x => x.UserId == part.ContentItem.Id).ToList();
-            var currentRoleRecords = currentUserRoleRecords.Select(x => x.Role).ToList();
-            var targetRoleRecords = userRoles.Select(x => _roleService.GetRoleByName(x)).ToList();
-            foreach (var addingRole in targetRoleRecords.Where(x => !currentRoleRecords.Contains(x))) {
-                _userRolesRepository.Create(new UserRolesPartRecord { UserId = part.ContentItem.Id, Role = addingRole });
-            }
+                var currentUserRoleRecords = _userRolesRepository.Fetch(x => x.UserId == part.ContentItem.Id).ToList();
+                var currentRoleRecords = currentUserRoleRecords.Select(x => x.Role).ToList();
+                var targetRoleRecords = userRoles.Select(x => _roleService.GetRoleByName(x)).ToList();
+                foreach (var addingRole in targetRoleRecords.Where(x => !currentRoleRecords.Contains(x))) {
+                    _userRolesRepository.Create(new UserRolesPartRecord { UserId = part.ContentItem.Id, Role = addingRole });
+                }
+            });
         }
 
         protected override void Exporting(UserRolesPart part, ContentManagement.Handlers.ExportContentContext context) {

src/Orchard.Web/Modules/Orchard.Search/Drivers/AdminSearchSettingsPartDriver.cs

@@ -1,6 +1,7 @@
 using System.Linq;
 using Orchard.ContentManagement;
 using Orchard.ContentManagement.Drivers;
+using Orchard.ContentManagement.Handlers;
 using Orchard.Environment.Extensions;
 using Orchard.Indexing;
 using Orchard.Search.Models;
@@ -37,5 +38,16 @@ namespace Orchard.Search.Drivers {
                 return shapeHelper.EditorTemplate(TemplateName: "Parts/AdminSearch.SiteSettings", Model: model, Prefix: Prefix);
             }).OnGroup("search");
         }
+        
+        protected override void Importing(AdminSearchSettingsPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
+            context.ImportAttribute(part.PartDefinition.Name, "SearchFields", value => {
+                part.Store("SearchFields", value);
+            });
+        }
     }
-}
+}

src/Orchard.Web/Modules/Orchard.Search/Drivers/SearchSettingsPartDriver.cs

@@ -79,15 +79,14 @@ namespace Orchard.Search.Drivers {
         }
 
         protected override void Importing(SearchSettingsPart part, ImportContentContext context) {
-            var xElement = context.Data.Element(part.PartDefinition.Name);
-            if (xElement == null) return;
-            
-            var searchFields = xElement.Attribute("SearchFields");
-            if (searchFields != null) {
-                searchFields.Remove();
-
-                part.Store("SearchFields", searchFields.Value); 
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
             }
+
+            context.ImportAttribute(part.PartDefinition.Name, "SearchFields", value => {
+                part.Store("SearchFields", value);
+            });
         }
     }
 }

src/Orchard.Web/Modules/Orchard.SecureSocketsLayer/Drivers/SslSettingsPartDriver.cs

@@ -36,7 +36,6 @@ namespace Orchard.SecureSocketsLayer.Drivers {
         }
 
         protected override void Importing(SslSettingsPart part, ImportContentContext context) {
-            base.Importing(part, context);
             _signals.Trigger(SslSettingsPart.CacheKey);
         }
     }

src/Orchard.Web/Modules/Orchard.Tags/Drivers/TagCloudDriver.cs

@@ -43,6 +43,11 @@ namespace Orchard.Tags.Drivers {
         }
 
         protected override void Importing(TagCloudPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             part.Slug = context.Attribute(part.PartDefinition.Name, "Slug");
             part.Buckets = Convert.ToInt32(context.Attribute(part.PartDefinition.Name, "Buckets"));
         }

src/Orchard.Web/Modules/Orchard.Tags/Drivers/TagsPartDriver.cs

@@ -70,6 +70,11 @@ namespace Orchard.Tags.Drivers {
         }
 
         protected override void Importing(TagsPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var tagString = context.Attribute(part.PartDefinition.Name, "Tags");
             if (tagString != null) {
                 var tags = tagString.Split(new[] {","}, StringSplitOptions.RemoveEmptyEntries);

src/Orchard.Web/Modules/Orchard.Taxonomies/Drivers/TaxonomyNavigationPartDriver.cs

@@ -101,6 +101,11 @@ namespace Orchard.Taxonomies.Drivers {
         }
 
         protected override void Importing(TaxonomyNavigationPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             part.DisplayContentCount = Boolean.Parse(context.Attribute(part.PartDefinition.Name, "DisplayContentCount"));
             part.DisplayRootTerm = Boolean.Parse(context.Attribute(part.PartDefinition.Name, "DisplayRootTerm"));
             part.HideEmptyTerms = Boolean.Parse(context.Attribute(part.PartDefinition.Name, "HideEmptyTerms"));

src/Orchard.Web/Modules/Orchard.Taxonomies/Drivers/TaxonomyPartDriver.cs

@@ -65,6 +65,11 @@ namespace Orchard.Taxonomies.Drivers {
         }
 
         protected override void Importing(TaxonomyPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             part.TermTypeName = context.Attribute(part.PartDefinition.Name, "TermTypeName");
         }
     }

src/Orchard.Web/Modules/Orchard.Taxonomies/Drivers/TermPartDriver.cs

@@ -126,6 +126,11 @@ namespace Orchard.Taxonomies.Drivers {
         }
 
         protected override void Importing(TermPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             part.Count = Int32.Parse(context.Attribute(part.PartDefinition.Name, "Count"));
             part.Selectable = Boolean.Parse(context.Attribute(part.PartDefinition.Name, "Selectable"));
             part.Weight = Int32.Parse(context.Attribute(part.PartDefinition.Name, "Weight"));

src/Orchard.Web/Modules/Orchard.Templates/Drivers/ShapePartDriver.cs

@@ -58,6 +58,11 @@ namespace Orchard.Templates.Drivers {
         }
 
         protected override void Importing(ShapePart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var shapeElement = context.Data.Element(part.PartDefinition.Name);
 
             if (shapeElement != null)

src/Orchard.Web/Modules/Orchard.Templates/Services/RazorTemplateProcessor.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Text;
+using System.Web;
 using System.Web.Mvc;
 using System.Web.UI;
 using System.Web.WebPages;
@@ -14,6 +15,7 @@ namespace Orchard.Templates.Services {
     [OrchardFeature("Orchard.Templates.Razor")]
     public class RazorTemplateProcessor : TemplateProcessorImpl {
         private readonly IRazorCompiler _compiler;
+        private readonly HttpContextBase _httpContextBase;
         private readonly IWorkContextAccessor _wca;
 
         public override string Type {
@@ -22,9 +24,11 @@ namespace Orchard.Templates.Services {
 
         public RazorTemplateProcessor(
             IRazorCompiler compiler,
+            HttpContextBase httpContextBase,
             IWorkContextAccessor wca) {
 
             _compiler = compiler;
+            _httpContextBase = httpContextBase;
             _wca = wca;
             Logger = NullLogger.Instance;
         }
@@ -37,7 +41,7 @@ namespace Orchard.Templates.Services {
 
         public override string Process(string template, string name, DisplayContext context = null, dynamic model = null) {
             if (String.IsNullOrEmpty(template))
-                return String.Empty;
+                return string.Empty;
 
             var compiledTemplate = _compiler.CompileRazor(template, name, new Dictionary<string, object>());
             var result = ActivateAndRenderTemplate(compiledTemplate, context, null, model);
@@ -69,10 +73,9 @@ namespace Orchard.Templates.Services {
                         // Setup a fake view context in order to support razor syntax inside of HTML attributes,
                         // for instance: <a href="@WorkContext.CurrentSite.BaseUrl">Homepage</a>.
                         var viewData = new ViewDataDictionary(model);
-                        var httpContext = _wca.GetContext().HttpContext;
                         obj.ViewContext = new ViewContext(
                             new ControllerContext(
-                                httpContext.Request.RequestContext,
+                                _httpContextBase.Request.RequestContext,
                                 new StubController()),
                                 new StubView(),
                                 viewData,
@@ -80,7 +83,7 @@ namespace Orchard.Templates.Services {
                                 htmlWriter);
 
                         obj.ViewData = viewData;
-                        obj.WebPageContext = new WebPageContext(httpContext, obj as WebPageRenderingBase, model);
+                        obj.WebPageContext = new WebPageContext(_httpContextBase, obj as WebPageRenderingBase, model);
                         obj.WorkContext = _wca.GetContext();
                     }
 

src/Orchard.Web/Modules/Orchard.Users/Drivers/UserPartDriver.cs

@@ -11,6 +11,11 @@ namespace Orchard.Users.Drivers {
     public class UserPartDriver : ContentPartDriver<UserPart> {
 
         protected override void Importing(UserPart part, ContentManagement.Handlers.ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             part.Email = context.Attribute(part.PartDefinition.Name, "Email");
             part.EmailChallengeToken = context.Attribute(part.PartDefinition.Name, "EmailChallengeToken");
             part.EmailStatus = (UserStatus)Enum.Parse(typeof(UserStatus), context.Attribute(part.PartDefinition.Name, "EmailStatus"));

src/Orchard.Web/Modules/Orchard.Widgets/Drivers/LayerPartDriver.cs

@@ -64,6 +64,11 @@ namespace Orchard.Widgets.Drivers {
         }
 
         protected override void Importing(LayerPart part, ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var name = context.Attribute(part.PartDefinition.Name, "Name");
             if (name != null) {
                 part.Name = name;

src/Orchard.Web/Modules/Orchard.Widgets/Drivers/WidgetPartDriver.cs

@@ -75,6 +75,11 @@ namespace Orchard.Widgets.Drivers {
         }
 
         protected override void Importing(WidgetPart part, ContentManagement.Handlers.ImportContentContext context) {
+            // Don't do anything if the tag is not specified.
+            if (context.Data.Element(part.PartDefinition.Name) == null) {
+                return;
+            }
+
             var title = context.Attribute(part.PartDefinition.Name, "Title");
             if (title != null) {
                 part.Title = title;

src/Orchard.Web/Modules/Orchard.Workflows/Controllers/AdminController.cs

@@ -23,6 +23,7 @@ using Orchard.UI.Notify;
 using Orchard.Workflows.Models;
 using Orchard.Workflows.Services;
 using Orchard.Workflows.ViewModels;
+using Orchard.Workflows.Helpers;
 
 namespace Orchard.Workflows.Controllers {
     [ValidateInput(false)]
@@ -298,7 +299,7 @@ namespace Orchard.Workflows.Controllers {
                 dynamic activity = new JObject();
                 activity.Name = x.Name;
                 activity.Id = x.Id;
-                activity.ClientId = x.Name + "_" + x.Id;
+                activity.ClientId = x.GetClientId();
                 activity.Left = x.X;
                 activity.Top = x.Y;
                 activity.Start = x.Start;
@@ -323,7 +324,7 @@ namespace Orchard.Workflows.Controllers {
 
         [HttpPost, ActionName("Edit")]
         [FormValueRequired("submit.Save")]
-        public ActionResult EditPost(int id, string localId, string data) {
+        public ActionResult EditPost(int id, string localId, string data, bool clearWorkflows) {
             if (!Services.Authorizer.Authorize(StandardPermissions.SiteOwner, T("Not authorized to edit workflows")))
                 return new HttpUnauthorizedResult();
 
@@ -339,7 +340,6 @@ namespace Orchard.Workflows.Controllers {
             var activitiesIndex = new Dictionary<string, ActivityRecord>();
 
             workflowDefinitionRecord.ActivityRecords.Clear();
-            workflowDefinitionRecord.WorkflowRecords.Clear();
 
             foreach (var activity in state.Activities) {
                 ActivityRecord activityRecord;
@@ -367,9 +367,32 @@ namespace Orchard.Workflows.Controllers {
                 });
             }
 
+            if (clearWorkflows) {
+                workflowDefinitionRecord.WorkflowRecords.Clear();
+            }
+            else {
+                foreach (var workflowRecord in workflowDefinitionRecord.WorkflowRecords) {
+                    // Update any awaiting activity records with the new activity record.
+                    foreach (var awaitingActivityRecord in workflowRecord.AwaitingActivities) {
+                        var clientId = awaitingActivityRecord.ActivityRecord.GetClientId();
+                        if (activitiesIndex.ContainsKey(clientId)) {
+                            awaitingActivityRecord.ActivityRecord = activitiesIndex[clientId];
+                        }
+                        else {
+                            workflowRecord.AwaitingActivities.Remove(awaitingActivityRecord);
+                        }
+                    }
+                    // Remove any workflows with no awaiting activities.
+                    if (!workflowRecord.AwaitingActivities.Any()) {
+                        workflowDefinitionRecord.WorkflowRecords.Remove(workflowRecord);
+                    }
+                }
+            }
+
             Services.Notifier.Information(T("Workflow saved successfully"));
 
-            return RedirectToAction("Edit", new { id, localId });
+            // Don't pass the localId to force the activites to refresh and use the deterministic clientId.
+            return RedirectToAction("Edit", new { id });
         }
 
         [HttpPost, ActionName("Edit")]

src/Orchard.Web/Modules/Orchard.Workflows/Models/ActivityRecord.cs

@@ -38,5 +38,14 @@ namespace Orchard.Workflows.Models {
         /// containing this activity.
         /// </summary>
         public virtual WorkflowDefinitionRecord WorkflowDefinitionRecord { get; set; }
+
+
+        /// <summary>
+        /// Gets the Id which can be used on the client. 
+        /// </summary>
+        /// <returns>An unique Id to represent this activity on the client.</returns>
+        public string GetClientId() {
+            return Name + "_" + Id;
+        }
     }
 }

src/Orchard.Web/Modules/Orchard.Workflows/Views/Admin/Edit.cshtml

@@ -7,6 +7,7 @@
     Style.Require("WorkflowsAdmin");
     Style.Require("WorkflowsActivities");
     Style.Require("jQueryUI_Orchard");
+    Script.Require("jQueryUI_Dialog").AtFoot();
     Script.Require("jsPlumb").AtFoot();
     Script.Include("orchard-workflows-serialize.js").AtFoot();
     Script.Include("orchard-workflows.js").AtFoot();
@@ -74,23 +75,41 @@
 @Html.Hidden("data", String.Empty)
 
 @Html.Hidden("confirm-delete-activity", T("Are you sure you want to remove this activity?"))
-@Html.Hidden("confirm-delete-instances", T("Are you sure you want to remove running instances of this workflow?"))
+@Html.Hidden("confirm-delete-instances", T("You have running instances of this workflow, do you want to stop them?"))
 
     using (Script.Foot()) {
 <script type="text/javascript">
     //<![CDATA[
-    $("form").submit(function () {
-        saveLocal(localId);
-        var workflow = loadWorkflow(localId);
-        var data = JSON.stringify(workflow);
-        $("[name='data']").val(data);
+    $("form").submit(function (e, submit, clearWorkflows) {
+        if(submit){
+            saveLocal(localId);
+            var workflow = loadWorkflow(localId);
+            var data = JSON.stringify(workflow);
+            $("[name='data']").val(data);
+            var values = [$("<input>", { type: "hidden", name: "clearWorkflows", value: clearWorkflows }), $("<input>", { type: "hidden", name: "submit.Save", value: "Save" })];
+            $(this).append(values);
+            return true;
+        }
+
+        e.preventDefault();
 
         $.ajax({
             url: stateUrl + "/" + $("#id").val(),
             async: false,
             success: function(state) {
-                if(state.isRunning && !confirm($("#confirm-delete-instances").val())) {
-                    e.preventDefault();
+                if (state.isRunning) {
+                    var dialog = $('<p>' + $("#confirm-delete-instances").val() + '</p>').dialog({
+                        buttons: {
+                            '@T("Yes")': function() { $('form').trigger('submit', [true, true]); },
+                            '@T("No")': function() { $('form').trigger('submit', [true, false]); },
+                            '@T("Cancel")': function() {
+                                dialog.dialog('close');
+                            }
+                        }
+                    });
+                } 
+                else {
+                    $('form').trigger('submit', [true, false]);
                 }
             }
         });

src/Orchard/BackgroundHttpContextFactory.cs

@@ -0,0 +1,33 @@
+using System.IO;
+using System.Web;
+using Orchard.Settings;
+
+namespace Orchard {
+    /// <summary>
+    /// A factory class that creates an HttpContext instance and initializes the HttpContext.Current property with that instance.
+    /// This is useful when rendering views from a background thread, as some Html Helpers access HttpContext.Current directly, thus preventing a NullReferenceException.
+    /// </summary>
+    public class BackgroundHttpContextFactory : IBackgroundHttpContextFactory {
+        public const string IsBackgroundHttpContextKey = "IsBackgroundHttpContext";
+        private readonly ISiteService _siteService;
+        public BackgroundHttpContextFactory(ISiteService siteService) {
+            _siteService = siteService;
+        }
+
+        public HttpContext CreateHttpContext() {
+            var url = _siteService.GetSiteSettings().BaseUrl;
+            var httpContext = new HttpContext(new HttpRequest("", url, ""), new HttpResponse(new StringWriter()));
+
+            httpContext.Items[IsBackgroundHttpContextKey] = true;
+
+            return httpContext;
+        }
+
+        public void InitializeHttpContext() {
+            if (HttpContext.Current != null)
+                return;
+
+            HttpContext.Current = CreateHttpContext();
+        }
+    }
+}

src/Orchard/DisplayManagement/Descriptors/ShapeTemplateStrategy/ShapeTemplateBindingStrategy.cs

@@ -179,8 +179,8 @@ namespace Orchard.DisplayManagement.Descriptors.ShapeTemplateStrategy {
 
         private ControllerContext CreateControllerContext() {
             var controller = new StubController();
-            var httpContext = _workContextAccessor.GetContext().HttpContext;
-            var requestContext = httpContext.Request.RequestContext;
+            var httpContext = _workContextAccessor.GetContext().Resolve<HttpContextBase>();
+            var requestContext = _workContextAccessor.GetContext().Resolve<RequestContext>();
             var routeData = requestContext.RouteData;
 
             routeData.DataTokens["IWorkContextAccessor"] = _workContextAccessor;

src/Orchard/DisplayManagement/ShapeDisplay.cs

@@ -1,6 +1,8 @@
 using System.Collections.Generic;
 using System.Linq;
+using System.Web;
 using System.Web.Mvc;
+using System.Web.Routing;
 using Orchard.DisplayManagement.Implementation;
 using Orchard.DisplayManagement.Shapes;
 
@@ -8,24 +10,28 @@ namespace Orchard.DisplayManagement {
     public class ShapeDisplay : IShapeDisplay {
         private readonly IDisplayHelperFactory _displayHelperFactory;
         private readonly IWorkContextAccessor _workContextAccessor;
+        private readonly HttpContextBase _httpContextBase;
+        private readonly RequestContext _requestContext;
 
         public ShapeDisplay(
-            IDisplayHelperFactory displayHelperFactory,
-            IWorkContextAccessor workContextAccessor) {
+            IDisplayHelperFactory displayHelperFactory, 
+            IWorkContextAccessor workContextAccessor, 
+            HttpContextBase httpContextBase,
+            RequestContext requestContext) {
             _displayHelperFactory = displayHelperFactory;
             _workContextAccessor = workContextAccessor;
+            _httpContextBase = httpContextBase;
+            _requestContext = requestContext;
         }
 
         public string Display(Shape shape) {
-            return Display((object)shape);
+            return Display((object) shape);
         }
 
         public string Display(object shape) {
-            var workContext = _workContextAccessor.GetContext();
-            var httpContext = workContext.HttpContext;
             var viewContext = new ViewContext {
-                HttpContext = httpContext,
-                RequestContext = httpContext.Request.RequestContext
+                HttpContext = _httpContextBase, 
+                RequestContext = _requestContext
             };
             viewContext.RouteData.DataTokens["IWorkContextAccessor"] = _workContextAccessor;
             var display = _displayHelperFactory.CreateHelper(viewContext, new ViewDataContainer());

src/Orchard/Environment/DefaultOrchardShell.cs

@@ -15,7 +15,7 @@ using IModelBinderProvider = Orchard.Mvc.ModelBinders.IModelBinderProvider;
 
 namespace Orchard.Environment {
     public class DefaultOrchardShell : IOrchardShell {
-        private readonly Func<Owned<IOrchardShellEvents>> _eventsFactory;
+        private readonly IWorkContextAccessor _workContextAccessor;
         private readonly IEnumerable<IRouteProvider> _routeProviders;
         private readonly IEnumerable<IHttpRouteProvider> _httpRouteProviders;
         private readonly IRoutePublisher _routePublisher;
@@ -26,7 +26,7 @@ namespace Orchard.Environment {
         private readonly ShellSettings _shellSettings;
 
         public DefaultOrchardShell(
-            Func<Owned<IOrchardShellEvents>> eventsFactory,
+            IWorkContextAccessor workContextAccessor,
             IEnumerable<IRouteProvider> routeProviders,
             IEnumerable<IHttpRouteProvider> httpRouteProviders,
             IRoutePublisher routePublisher,
@@ -35,8 +35,7 @@ namespace Orchard.Environment {
             ISweepGenerator sweepGenerator,
             IEnumerable<IOwinMiddlewareProvider> owinMiddlewareProviders,
             ShellSettings shellSettings) {
-
-            _eventsFactory = eventsFactory;
+            _workContextAccessor = workContextAccessor;
             _routeProviders = routeProviders;
             _httpRouteProviders = httpRouteProviders;
             _routePublisher = routePublisher;
@@ -74,8 +73,10 @@ namespace Orchard.Environment {
             _routePublisher.Publish(allRoutes, pipeline);
             _modelBinderPublisher.Publish(_modelBinderProviders.SelectMany(provider => provider.GetModelBinders()));
 
-            using (var events = _eventsFactory()) {
-                events.Value.Activated();
+            using (var scope = _workContextAccessor.CreateWorkContextScope()) {
+                using (var events = scope.Resolve<Owned<IOrchardShellEvents>>()) {
+                    events.Value.Activated();
+                }
             }
             
             _sweepGenerator.Activate();
@@ -83,10 +84,11 @@ namespace Orchard.Environment {
 
         public void Terminate() {
             SafelyTerminate(() => {
-                using (var events = _eventsFactory()) {
-                    var localEvents = events;
-                    SafelyTerminate(() => localEvents.Value.Terminating());
-                }
+                using (var scope = _workContextAccessor.CreateWorkContextScope()) {
+                    using (var events = scope.Resolve<Owned<IOrchardShellEvents>>()) {
+                        SafelyTerminate(() => events.Value.Terminating());
+                    }
+                }  
             });
 
             SafelyTerminate(() => _sweepGenerator.Terminate());

src/Orchard/Environment/OrchardStarter.cs

@@ -63,7 +63,7 @@ namespace Orchard.Environment {
             builder.RegisterType<AppDomainAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
             builder.RegisterType<GacAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
             builder.RegisterType<OrchardFrameworkAssemblyNameResolver>().As<IAssemblyNameResolver>().SingleInstance();
-            builder.RegisterType<HttpContextAccessor>().As<IHttpContextAccessor>().SingleInstance();
+            builder.RegisterType<HttpContextAccessor>().As<IHttpContextAccessor>().InstancePerDependency();
             builder.RegisterType<ViewsBackgroundCompilation>().As<IViewsBackgroundCompilation>().SingleInstance();
             builder.RegisterType<DefaultExceptionPolicy>().As<IExceptionPolicy>().SingleInstance();
             builder.RegisterType<DefaultCriticalErrorProvider>().As<ICriticalErrorProvider>().SingleInstance();

src/Orchard/Environment/WorkContextAccessor.cs

@@ -60,14 +60,11 @@ namespace Orchard.Environment {
                 return CreateWorkContextScope(httpContext);
 
             var workLifetime = _lifetimeScope.BeginLifetimeScope("work");
-            httpContext = _httpContextAccessor.CreateContext(workLifetime);
-            workLifetime.Resolve<WorkContextProperty<HttpContextBase>>().Value = httpContext;
 
             var events = workLifetime.Resolve<IEnumerable<IWorkContextEvents>>();
             events.Invoke(e => e.Started(), NullLogger.Instance);
 
             return new ThreadStaticScopeImplementation(
-                httpContext,
                 events,
                 workLifetime,
                 EnsureThreadStaticContexts(),
@@ -116,9 +113,8 @@ namespace Orchard.Environment {
             readonly WorkContext _workContext;
             readonly Action _disposer;
 
-            public ThreadStaticScopeImplementation(HttpContextBase httpContext, IEnumerable<IWorkContextEvents> events, ILifetimeScope lifetimeScope, ConcurrentDictionary<object, WorkContext> contexts, object workContextKey) {
+            public ThreadStaticScopeImplementation(IEnumerable<IWorkContextEvents> events, ILifetimeScope lifetimeScope, ConcurrentDictionary<object, WorkContext> contexts, object workContextKey) {
                 _workContext = lifetimeScope.Resolve<WorkContext>();
-                httpContext.Items[workContextKey] = _workContext;
                 contexts.AddOrUpdate(workContextKey, _workContext, (a, b) => _workContext);
 
                 _disposer = () => {
@@ -127,11 +123,6 @@ namespace Orchard.Environment {
                     WorkContext removedContext;
                     contexts.TryRemove(workContextKey, out removedContext);
                     lifetimeScope.Dispose();
-
-                    var staticHttpContext = httpContext as IDisposable;
-
-                    if(staticHttpContext != null)
-                        staticHttpContext.Dispose();
                 };
             }
 

src/Orchard/Environment/WorkContextModule.cs

@@ -6,7 +6,6 @@ using System.Web;
 using Autofac;
 using Autofac.Builder;
 using Autofac.Core;
-using Autofac.Features.Metadata;
 using Module = Autofac.Module;
 
 namespace Orchard.Environment {
@@ -24,10 +23,6 @@ namespace Orchard.Environment {
                 .As<WorkContextProperty<HttpContextBase>>()
                 .InstancePerMatchingLifetimeScope("work");
 
-            builder.Register(ctx => ctx.Resolve<WorkContextProperty<HttpContextBase>>().Value)
-                .As<HttpContextBase>()
-                .InstancePerDependency();
-
             builder.RegisterGeneric(typeof(WorkValues<>))
                 .InstancePerMatchingLifetimeScope("work");
 

src/Orchard/IBackgroundHttpContextFactory.cs

@@ -0,0 +1,8 @@
+using System.Web;
+
+namespace Orchard {
+    public interface IBackgroundHttpContextFactory : IDependency {
+        HttpContext CreateHttpContext();
+        void InitializeHttpContext();
+    }
+}

src/Orchard/IStaticHttpContextScopeFactory.cs

@@ -1,15 +0,0 @@
-using System;
-
-namespace Orchard {
-    /// <summary>
-    /// A factory class that creates an <see cref="StaticHttpContextScope"/> instance and initializes the HttpContext.Current property with that instance until the scope is disposed of.
-    /// This is useful when rendering views from a background thread, as some Html Helpers access HttpContext.Current directly, thus preventing a NullReferenceException.
-    /// </summary>
-    public interface IStaticHttpContextScopeFactory : IDependency {
-        /// <summary>
-        /// Creates a disposable static HttpContext scope. This is safe to use even if there is an actual HttpContext.Current instance.
-        /// </summary>
-        /// <returns></returns>
-        IDisposable CreateStaticScope();
-    }
-}

src/Orchard/Mvc/Extensions/HttpContextBaseExtensions.cs

@@ -0,0 +1,9 @@
+using System.Web;
+
+namespace Orchard.Mvc.Extensions {
+    public static class HttpContextBaseExtensions {
+        public static bool IsBackgroundContext(this HttpContextBase httpContextBase) {
+            return httpContextBase == null || httpContextBase is MvcModule.HttpContextPlaceholder;
+        }
+    }
+}

src/Orchard/Mvc/Extensions/HttpContextExtensions.cs

@@ -1,13 +0,0 @@
-using System.Web;
-
-namespace Orchard.Mvc.Extensions {
-    public static class HttpContextExtensions {
-        public static bool IsBackgroundContext(this HttpContextBase httpContext) {
-            return httpContext == null || httpContext is MvcModule.HttpContextPlaceholder;
-        }
-
-        public static bool IsBackgroundContext(this HttpContext httpContext) {
-            return httpContext == null || httpContext.Items.Contains(StaticHttpContextScopeFactory.IsBackgroundHttpContextKey);
-        }
-    }
-}

src/Orchard/Mvc/HttpContextAccessor.cs

@@ -1,40 +1,39 @@
 using System;
-using System.Collections.Concurrent;
 using System.Web;
-using Autofac;
-using Orchard.Mvc.Extensions;
 
 namespace Orchard.Mvc {
     public class HttpContextAccessor : IHttpContextAccessor {
-        readonly object _contextKey = new object();
-
-        [ThreadStatic]
-        static ConcurrentDictionary<object, HttpContextBase> _threadStaticContexts;
+        private HttpContextBase _httpContext;
 
         public HttpContextBase Current() {
-            if (!HttpContext.Current.IsBackgroundContext())
-                return new HttpContextWrapper(HttpContext.Current);
-
-            return GetContext();
+            var httpContext = GetStaticProperty();
+            return !IsBackgroundHttpContext(httpContext) ? new HttpContextWrapper(httpContext) : _httpContext;
         }
 
-        public HttpContextBase CreateContext(ILifetimeScope lifetimeScope) {
-            return new MvcModule.HttpContextPlaceholder(
-                _threadStaticContexts, 
-                _contextKey, 
-                () => "http://localhost" // Use a valid URL always for the fake request. The value itself doesn't matter.
-            );
+        public void Set(HttpContextBase httpContext) {
+            _httpContext = httpContext;
         }
 
-        private HttpContextBase GetContext() {
-            HttpContextBase context;
-            return ThreadStaticContexts.TryGetValue(_contextKey, out context) ? context : null;
+        private static bool IsBackgroundHttpContext(HttpContext httpContext) {
+            return httpContext == null || httpContext.Items.Contains(BackgroundHttpContextFactory.IsBackgroundHttpContextKey);
         }
 
-        static ConcurrentDictionary<object, HttpContextBase> ThreadStaticContexts {
-            get {
-                return _threadStaticContexts ?? (_threadStaticContexts = new ConcurrentDictionary<object, HttpContextBase>());
+        private static HttpContext GetStaticProperty() {
+            var httpContext = HttpContext.Current;
+            if (httpContext == null) {
+                return null;
             }
+
+            try {
+                // The "Request" property throws at application startup on IIS integrated pipeline mode.
+                if (httpContext.Request == null) {
+                    return null;
+                }
+            }
+            catch (Exception) {
+                return null;
+            }
+            return httpContext;
         }
     }
 }

src/Orchard/Mvc/IHttpContextAccessor.cs

@@ -1,9 +1,8 @@
 using System.Web;
-using Autofac;
 
 namespace Orchard.Mvc {
     public interface IHttpContextAccessor {
         HttpContextBase Current();
-        HttpContextBase CreateContext(ILifetimeScope lifetimeScope);
+        void Set(HttpContextBase httpContext);
     }
 }

src/Orchard/Mvc/MvcModule.cs

@@ -1,6 +1,5 @@
 using System;
 using System.Collections;
-using System.Collections.Concurrent;
 using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Globalization;
@@ -10,7 +9,6 @@ using System.Web.Instrumentation;
 using System.Web.Mvc;
 using System.Web.Routing;
 using Autofac;
-using Orchard.Mvc.Extensions;
 using Orchard.Mvc.Routes;
 using Orchard.Settings;
 
@@ -52,21 +50,15 @@ namespace Orchard.Mvc {
             // which requires activating the Site content item, which in turn requires a UrlHelper, which in turn requires a RequestContext,
             // thus preventing a StackOverflowException.
             var baseUrl = new Func<string>(() => siteService.GetSiteSettings().BaseUrl);
-            var httpContextBase = context.Resolve<IHttpContextAccessor>().Current();
+            var httpContextBase = new HttpContextPlaceholder(baseUrl);
 
-            if (httpContextBase == null) {
-                context.Resolve<IWorkContextAccessor>().CreateWorkContextScope();
-                return context.Resolve<IHttpContextAccessor>().Current();
-            }
-            
-            context.Resolve<IWorkContextAccessor>().CreateWorkContextScope(httpContextBase);
             return httpContextBase;
         }
 
         static RequestContext RequestContextFactory(IComponentContext context) {
             var httpContextAccessor = context.Resolve<IHttpContextAccessor>();
             var httpContext = httpContextAccessor.Current();
-            if (!httpContext.IsBackgroundContext()) {
+            if (httpContext != null) {
 
                 var mvcHandler = httpContext.Handler as MvcHandler;
                 if (mvcHandler != null) {
@@ -93,23 +85,16 @@ namespace Orchard.Mvc {
         /// <summary>
         /// Standin context for background tasks.
         /// </summary>
-        public class HttpContextPlaceholder : HttpContextBase, IDisposable {
+        public class HttpContextPlaceholder : HttpContextBase {
             private readonly Lazy<string> _baseUrl;
             private readonly IDictionary _items = new Dictionary<object, object>();
-            readonly Action _disposer;
 
-            public HttpContextPlaceholder(ConcurrentDictionary<object, HttpContextBase> contexts, object contextKey, Func<string> baseUrl) {
+            public HttpContextPlaceholder(Func<string> baseUrl) {
                 _baseUrl = new Lazy<string>(baseUrl);
-                contexts.AddOrUpdate(contextKey, this, (a, b) => this);
-
-                _disposer = () => {
-                    HttpContextBase removedContext;
-                    contexts.TryRemove(contextKey, out removedContext);
-                };
             }
 
             public override HttpRequestBase Request {
-                get { return new HttpRequestPlaceholder(this, new Uri(_baseUrl.Value)); }
+                get { return new HttpRequestPlaceholder(new Uri(_baseUrl.Value)); }
             }
 
             public override IHttpHandler Handler { get; set; }
@@ -118,10 +103,6 @@ namespace Orchard.Mvc {
                 get { return new HttpResponsePlaceholder(); }
             }
 
-            public override HttpSessionStateBase Session {
-                get { return null; }
-            }
-
             public override IDictionary Items {
                 get { return _items; }
             }
@@ -141,10 +122,6 @@ namespace Orchard.Mvc {
             public override object GetService(Type serviceType) {
                 return null;
             }
-
-            public void Dispose() {
-                _disposer();
-            }
         }
 
         public class HttpResponsePlaceholder : HttpResponseBase {
@@ -163,12 +140,9 @@ namespace Orchard.Mvc {
         /// standin context for background tasks. 
         /// </summary>
         public class HttpRequestPlaceholder : HttpRequestBase {
-            private readonly HttpContextBase _httpContext;
             private readonly Uri _uri;
-            private RequestContext _requestContext;
 
-            public HttpRequestPlaceholder(HttpContextBase httpContext, Uri uri) {
-                _httpContext = httpContext;
+            public HttpRequestPlaceholder(Uri uri) {
                 _uri = uri;
             }
 
@@ -227,7 +201,7 @@ namespace Orchard.Mvc {
                     return new NameValueCollection {
                         { "SERVER_PORT", _uri.Port.ToString(CultureInfo.InvariantCulture) },
                         { "HTTP_HOST", _uri.Authority.ToString(CultureInfo.InvariantCulture) },
-
+                        
                     };
                 }
             }
@@ -269,16 +243,6 @@ namespace Orchard.Mvc {
                     return new HttpBrowserCapabilitiesPlaceholder();
                 }
             }
-
-            public override RequestContext RequestContext {
-                get {
-                    if (_requestContext == null) {
-                        _requestContext = new RequestContext(_httpContext, new RouteData());
-                    }
-                    return _requestContext;
-                }
-                set { _requestContext = value; }
-            }
         }
 
         public class HttpBrowserCapabilitiesPlaceholder : HttpBrowserCapabilitiesBase {

src/Orchard/Orchard.Framework.csproj

@@ -56,6 +56,7 @@
     <WarningLevel>4</WarningLevel>
     <CodeAnalysisRuleSet>AllRules.ruleset</CodeAnalysisRuleSet>
     <Prefer32Bit>false</Prefer32Bit>
+    <NoWarn>0436</NoWarn>
   </PropertyGroup>
   <ItemGroup>
     <Reference Include="Autofac, Version=2.1.13.813, Culture=neutral, PublicKeyToken=17863af14b0044da, processorArchitecture=MSIL">
@@ -149,10 +150,12 @@
     <Reference Include="System.Xml.Linq" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="BackgroundHttpContextFactory.cs" />
     <Compile Include="Data\Migration\Schema\AddUniqueConstraintCommand.cs" />
     <Compile Include="Data\Migration\Schema\DropUniqueConstraintCommand.cs" />
     <Compile Include="Environment\Extensions\Models\LifecycleStatus.cs" />
     <Compile Include="Environment\ShellBuilders\ICompositionStrategy.cs" />
+    <Compile Include="IBackgroundHttpContextFactory.cs" />
     <Compile Include="Mvc\Updater.cs" />
     <Compile Include="Recipes\Models\ConfigurationContext.cs" />
     <Compile Include="Recipes\Models\RecipeBuilderStepConfigurationContext.cs" />
@@ -188,8 +191,6 @@
     <Compile Include="Security\NullMembershipService.cs" />
     <Compile Include="Security\Providers\DefaultSslSettingsProvider.cs" />
     <Compile Include="Security\Providers\DefaultMembershipValidationService.cs" />
-    <Compile Include="StaticHttpContextScope.cs" />
-    <Compile Include="StaticHttpContextScopeFactory.cs" />
     <Compile Include="Caching\DefaultCacheContextAccessor.cs" />
     <Compile Include="Caching\DefaultParallelCacheContext.cs" />
     <Compile Include="Caching\ICacheContextAccessor.cs" />
@@ -360,7 +361,7 @@
     <Compile Include="Mvc\DataAnnotations\LocalizedModelValidatorProvider.cs" />
     <Compile Include="Mvc\DataAnnotations\LocalizedRequiredAttribute.cs" />
     <Compile Include="Mvc\Extensions\RouteExtension.cs" />
-    <Compile Include="Mvc\Extensions\HttpContextExtensions.cs" />
+    <Compile Include="Mvc\Extensions\HttpContextBaseExtensions.cs" />
     <Compile Include="Mvc\FormValueRequiredAttribute.cs" />
     <Compile Include="Mvc\HttpContextAccessor.cs" />
     <Compile Include="Mvc\HttpContextWorkContext.cs" />
@@ -694,7 +695,6 @@
     <Compile Include="WebApi\Filters\OrchardApiActionFilterDispatcher.cs" />
     <Compile Include="WebApi\Routes\IHttpRouteProvider.cs" />
     <Compile Include="WebApi\Routes\StandardExtensionHttpRouteProvider.cs" />
-    <Compile Include="IStaticHttpContextScopeFactory.cs" />
     <Compile Include="WorkContextExtensions.cs" />
     <Compile Include="Mvc\ViewEngines\Razor\RazorCompilationEventsShim.cs" />
     <Compile Include="Mvc\ViewEngines\Razor\RazorViewEngineProvider.cs" />

src/Orchard/StaticHttpContextScope.cs

@@ -1,17 +0,0 @@
-using System;
-using System.Web;
-
-namespace Orchard {
-    public class StaticHttpContextScope : IDisposable {
-        private readonly HttpContext _previousHttpContext;
-
-        public StaticHttpContextScope(HttpContext stub) {
-            _previousHttpContext = HttpContext.Current;
-            HttpContext.Current = stub;
-        }
-
-        public void Dispose() {
-            HttpContext.Current = _previousHttpContext;
-        }
-    }
-}

src/Orchard/StaticHttpContextScopeFactory.cs

@@ -1,31 +0,0 @@
-using System;
-using System.IO;
-using System.Web;
-using Orchard.Settings;
-
-namespace Orchard {
-    public class StaticHttpContextScopeFactory : IStaticHttpContextScopeFactory {
-        private readonly Func<ISiteService> _siteService;
-        public StaticHttpContextScopeFactory(Func<ISiteService> siteService) {
-            _siteService = siteService;
-        }
-
-        public const string IsBackgroundHttpContextKey = "IsBackgroundHttpContext";
-
-        public IDisposable CreateStaticScope() {
-            // If there already is a current HttpContext, use that one as the stub.
-            if(HttpContext.Current != null)
-                return new StaticHttpContextScope(HttpContext.Current);
-
-            // We're in a background task (or some other static context like the console),
-            // so create a stub context so that Html Helpers can still be executed when rendering shapes in background tasks
-            // (sadly enought some Html Helpers access HttpContext.Current directly).
-            var url = _siteService().GetSiteSettings().BaseUrl;
-            var stub = new HttpContext(new HttpRequest("", url, ""), new HttpResponse(new StringWriter()));
-
-            stub.Items[IsBackgroundHttpContextKey] = true;
-
-            return new StaticHttpContextScope(stub);
-        }
-    }
-}

src/Orchard/Tasks/BackgroundService.cs

@@ -18,7 +18,8 @@ namespace Orchard.Tasks {
         public BackgroundService(
             IEnumerable<IBackgroundTask> tasks, 
             ITransactionManager transactionManager, 
-            ShellSettings shellSettings) {
+            ShellSettings shellSettings,
+            IBackgroundHttpContextFactory backgroundHttpContextFactory) {
 
             _tasks = tasks;
             _transactionManager = transactionManager;

src/Orchard/Tasks/SweepGenerator.cs

@@ -41,7 +41,7 @@ namespace Orchard.Tasks {
         }
 
         void Elapsed(object sender, ElapsedEventArgs e) {
-            // Current implementation disallows re-entrancy.
+            // current implementation disallows re-entrancy
             if (!System.Threading.Monitor.TryEnter(_timer))
                 return;
 
@@ -60,7 +60,7 @@ namespace Orchard.Tasks {
 
         public void DoWork() {
             using (var scope = _workContextAccessor.CreateWorkContextScope()) {
-                // Resolve the manager and invoke it.
+                // resolve the manager and invoke it
                 var manager = scope.Resolve<IBackgroundService>();
                 manager.Sweep();
             }

src/Package.json

@@ -1,4 +1,5 @@
 {
+    "private": true,
     "devDependencies": {
         "glob": "^5.0.14",
         "path-posix": "^1.0.0",