Create a virtual path provider for WebForms files

This is so that we dynamically add the relevant <%@ Assembly Name="" %>
directive to WebForms files served from modules which have been dynamically
compiled and stored in the "~/App_Data/Dependencies" folder.

--HG--
branch : dev

src/Orchard.Web/Global.asax.cs

@@ -3,13 +3,12 @@ using System.IO;
 using System.Linq;
 using System.Reflection;
 using System.Web;
+using System.Web.Hosting;
 using System.Web.Mvc;
 using System.Web.Routing;
 using Autofac;
-using Autofac.Builder;
-using Autofac.Integration.Web;
-using Autofac.Integration.Web.Mvc;
 using Orchard.Environment;
+using Orchard.Environment.Extensions.Loaders;
 
 namespace Orchard.Web {
     // Note: For instructions on enabling IIS6 or IIS7 classic mode, 
@@ -32,6 +31,7 @@ namespace Orchard.Web {
 
             RegisterRoutes(RouteTable.Routes);
 
+            HostingEnvironment.RegisterVirtualPathProvider(new WebFormsExtensionsVirtualPathProvider());
             _host = OrchardStarter.CreateHost(MvcSingletons);
             _host.Initialize();
 
@@ -101,6 +101,5 @@ namespace Orchard.Web {
             builder.RegisterInstance(ModelMetadataProviders.Current);
             builder.RegisterInstance(ViewEngines.Engines);
         }
-
     }
 }

src/Orchard/Environment/Extensions/Loaders/WebFormsExtensionsVirtualFile.cs

@@ -0,0 +1,51 @@
+using System.IO;
+using System.Reflection;
+using System.Web.Hosting;
+
+namespace Orchard.Environment.Extensions.Loaders {
+    public class WebFormsExtensionsVirtualFile : VirtualFile {
+        private readonly Assembly _assembly;
+        private readonly VirtualFile _actualFile;
+
+        public WebFormsExtensionsVirtualFile(string virtualPath, Assembly assembly, VirtualFile actualFile)
+            : base(virtualPath) {
+            _assembly = assembly;
+            _actualFile = actualFile;
+        }
+
+        public override string Name {
+            get {
+                return _actualFile.Name;
+            }
+        }
+
+        public override bool IsDirectory {
+            get {
+                return _actualFile.IsDirectory;
+            }
+        }
+
+        public override Stream Open() {
+            var reader = new StreamReader(_actualFile.Open());
+            var memoryStream = new MemoryStream();
+            int length;
+            using (var writer = new StreamWriter(memoryStream)) {
+
+                bool assemblyDirectiveAdded = false;
+                for (var line = reader.ReadLine(); line != null; line = reader.ReadLine()) {
+
+                    if (!string.IsNullOrWhiteSpace(line) && !assemblyDirectiveAdded) {
+                        line += string.Format("<%@ Assembly Name=\"{0}\"%>", _assembly);
+                        assemblyDirectiveAdded = true;
+                    }
+
+                    writer.WriteLine(line);
+                }
+                writer.Flush();
+                length = (int)memoryStream.Length;
+            }
+            var result = new MemoryStream(memoryStream.GetBuffer(), 0, length);
+            return result;
+        }
+    }
+}

src/Orchard/Environment/Extensions/Loaders/WebFormsExtensionsVirtualPathProvider.cs

@@ -0,0 +1,77 @@
+using System;
+using System.Linq;
+using System.Web.Hosting;
+using Orchard.FileSystems.Dependencies;
+
+namespace Orchard.Environment.Extensions.Loaders {
+    public class WebFormsExtensionsVirtualPathProvider : VirtualPathProvider {
+        private IDependenciesFolder _dependenciesFolder;
+        private const string _prefix1 = "~/Modules/";
+        private const string _prefix2 = "/Modules/";
+
+        public WebFormsExtensionsVirtualPathProvider() {
+        }
+
+        protected override void Initialize() {
+            base.Initialize();
+            _dependenciesFolder = new DefaultDependenciesFolder(new DefaultVirtualPathProvider());
+        }
+
+        public override bool DirectoryExists(string virtualDir) {
+            return Previous.DirectoryExists(virtualDir);
+        }
+
+        public override bool FileExists(string virtualPath) {
+            return Previous.FileExists(virtualPath);
+        }
+
+        public override VirtualFile GetFile(string virtualPath) {
+            var actualFile = Previous.GetFile(virtualPath);
+
+            var prefix = PrefixMatch(virtualPath);
+            if (prefix == null)
+                return actualFile;
+
+            var extension = ExtensionMatch(virtualPath, ".ascx", ".aspx", ".master");
+            if (extension == null)
+                return actualFile;
+
+            var moduleName = ModuleMatch(virtualPath, prefix);
+            if (moduleName == null)
+                return actualFile;
+
+            // It looks like we have a module name. Is this one of this modules
+            // with its assembly stored in the "App_Data/Dependencies" folder?
+            var assembly = _dependenciesFolder.LoadAssembly(moduleName);
+            if (assembly == null)
+                return actualFile;
+
+            // Yes: we need to wrap the VirtualFile to add the <%@ Assembly Name=".."%> directive
+            // in the content.
+            return new WebFormsExtensionsVirtualFile(virtualPath, assembly, actualFile);
+        }
+
+        private string ModuleMatch(string virtualPath, string prefix) {
+            var index = virtualPath.IndexOf('/', prefix.Length, virtualPath.Length - prefix.Length);
+            if (index < 0)
+                return null;
+
+            var moduleName = virtualPath.Substring(prefix.Length, index - prefix.Length);
+            return (string.IsNullOrEmpty(moduleName) ? null : moduleName);
+        }
+
+        private string ExtensionMatch(string virtualPath, params string[] extensions) {
+            return extensions
+                .FirstOrDefault(e => virtualPath.EndsWith(e, StringComparison.OrdinalIgnoreCase));
+        }
+
+        private string PrefixMatch(string virtualPath) {
+            if (virtualPath.StartsWith(_prefix1))
+                return _prefix1;
+            if (virtualPath.StartsWith(_prefix2))
+                return _prefix2;
+            return null;
+
+        }
+    }
+}

src/Orchard/Orchard.Framework.csproj

@@ -341,6 +341,8 @@
     <Compile Include="Data\DataModule.cs" />
     <Compile Include="Data\Orderable.cs" />
     <Compile Include="Environment\DefaultOrchardShell.cs" />
+    <Compile Include="Environment\Extensions\Loaders\WebFormsExtensionsVirtualPathProvider.cs" />
+    <Compile Include="Environment\Extensions\Loaders\WebFormsExtensionsVirtualFile.cs" />
     <Compile Include="Environment\IHostEnvironment.cs" />
     <Compile Include="FileSystems\Dependencies\IDependenciesFolder.cs" />
     <Compile Include="Environment\Extensions\Loaders\ProbingExtensionLoader.cs" />