EmbeddedResourcesVirtualPathProvider.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Web;
using System.Web.Caching;
using System.Web.Hosting;

namespace InfoCaster.Umbraco.TextFieldPreviewable
{
	public class EmbeddedResourcesVirtualPathProvider : VirtualPathProvider
	{
		public EmbeddedResourcesVirtualPathProvider()
		{
		}

		private bool IsEmbeddedResourcePath(string virtualPath)
		{
			var checkPath = VirtualPathUtility.ToAppRelative(virtualPath);
			return checkPath.StartsWith("~/Umbraco/TextFieldPreviewable/", StringComparison.InvariantCultureIgnoreCase);
		}

		public override bool FileExists(string virtualPath)
		{
			return IsEmbeddedResourcePath(virtualPath) || base.FileExists(virtualPath);
		}

		public override VirtualFile GetFile(string virtualPath)
		{
			if (IsEmbeddedResourcePath(virtualPath))
				return new EmbeddedResourceVirtualFile(virtualPath);
			return base.GetFile(virtualPath);
		}

		public override CacheDependency GetCacheDependency(string virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart)
		{
			if (IsEmbeddedResourcePath(virtualPath))
				return null;
			return base.GetCacheDependency(virtualPath, virtualPathDependencies, utcStart);
		}
	}

	public class EmbeddedResourceVirtualFile : VirtualFile
	{
		string _path;

		public EmbeddedResourceVirtualFile(string virtualPath)
			: base(virtualPath)
		{
			_path = VirtualPathUtility.ToAppRelative(virtualPath);
		}

		public override Stream Open()
		{
			var resourceName = _path.Split('/').Last();
			var assembly = GetType().Assembly;
			if (assembly != null)
				return assembly.GetManifestResourceStream(resourceName);
			return null;
		}
	}
}