mcs/class/System.Web/System.Web.Hosting/VirtualPathProvider.cs

   1 //
   2 // System.Web.Hosting.VirtualPathProvider
   3 //
   4 // Author:
   5 //      Gonzalo Paniagua Javier (gonzalo@ximian.com)
   6 //
   7 //
   8 // Copyright (C) 2006 Novell, Inc (http://www.novell.com)
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29 using System;
  30 using System.Collections;
  31 using System.IO;
  32 using System.Web.Caching;
  33 using System.Web.Util;
  34
  35 namespace System.Web.Hosting {
  36
  37         public abstract class VirtualPathProvider : MarshalByRefObject
  38         {
  39                 VirtualPathProvider prev;
  40
  41                 protected VirtualPathProvider ()
  42                 {
  43                 }
  44
  45                 protected internal VirtualPathProvider Previous {
  46                         get { return prev; }
  47                 }
  48
  49                 protected virtual void Initialize ()
  50                 {
  51                 }
  52
  53                 internal void InitializeAndSetPrevious (VirtualPathProvider prev)
  54                 {
  55                         this.prev = prev;
  56                         Initialize ();
  57                 }
  58
  59                 public virtual string CombineVirtualPaths (string basePath, string relativePath)
  60                 {
  61                         return VirtualPathUtility.Combine (basePath, relativePath);
  62                 }
  63
  64                 public virtual bool DirectoryExists (string virtualDir)
  65                 {
  66                         if (prev != null)
  67                                 return prev.DirectoryExists (virtualDir);
  68
  69                         return false;
  70                 }
  71
  72                 public virtual bool FileExists (string virtualPath)
  73                 {
  74                         if (prev != null)
  75                                 return prev.FileExists (virtualPath);
  76
  77                         return false;
  78                 }
  79
  80                 public virtual CacheDependency GetCacheDependency (string virtualPath, IEnumerable virtualPathDependencies, DateTime utcStart)
  81                 {
  82                         if (prev != null)
  83                                 return prev.GetCacheDependency (virtualPath, virtualPathDependencies, utcStart);
  84
  85                         return null;
  86                 }
  87
  88                 public virtual string GetCacheKey (string virtualPath)
  89                 {
  90                         if (prev != null)
  91                                 return prev.GetCacheKey (virtualPath);
  92
  93                         return null;
  94                 }
  95
  96                 public virtual VirtualDirectory GetDirectory (string virtualDir)
  97                 {
  98                         if (prev != null)
  99                                 return prev.GetDirectory (virtualDir);
 100
 101                         return null;
 102                 }
 103
 104                 public virtual VirtualFile GetFile (string virtualPath)
 105                 {
 106                         if (prev != null)
 107                                 return prev.GetFile (virtualPath);
 108
 109                         return null;
 110                 }
 111
 112                 public virtual string GetFileHash (string virtualPath, IEnumerable virtualPathDependencies)
 113                 {
 114                         if (prev != null)
 115                                 return prev.GetFileHash (virtualPath, virtualPathDependencies);
 116
 117                         return null;
 118                 }
 119
 120                 public override object InitializeLifetimeService ()
 121                 {
 122                         return null; // forever young
 123                 }
 124
 125                 public static Stream OpenFile (string virtualPath)
 126                 {
 127                         // This thing throws a nullref when we're not inside an ASP.NET appdomain, which is what MS does.
 128                         VirtualPathProvider provider = HostingEnvironment.VirtualPathProvider;
 129                         VirtualFile file = provider.GetFile (virtualPath);
 130                         if (file != null)
 131                                 return file.Open ();
 132
 133                         return null;
 134                 }
 135         }
 136 }
 137