MonoRail/Castle.MonoRail.Framework/TransformFilter.cs

   1 // Copyright 2004-2007 Castle Project - http://www.castleproject.org/
   2 //
   3 // Licensed under the Apache License, Version 2.0 (the "License");
   4 // you may not use this file except in compliance with the License.
   5 // You may obtain a copy of the License at
   6 //
   7 //     http://www.apache.org/licenses/LICENSE-2.0
   8 //
   9 // Unless required by applicable law or agreed to in writing, software
  10 // distributed under the License is distributed on an "AS IS" BASIS,
  11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12 // See the License for the specific language governing permissions and
  13 // limitations under the License.
  14
  15 namespace Castle.MonoRail.Framework
  16 {
  17         using System;
  18         using System.IO;
  19
  20         /// <summary>
  21         /// Abstract base class for HttpFilters.
  22         /// </summary>
  23         public abstract class TransformFilter : Stream, ITransformFilter
  24         {
  25                 private Stream baseStream;
  26                 private bool closed;
  27
  28                 /// <summary>
  29                 /// Base class holds the underlying stream.
  30                 /// </summary>
  31                 /// <param name="baseStream">The stream to write to after filtering.</param>
  32                 public TransformFilter(Stream baseStream)
  33                 {
  34                         this.baseStream = baseStream;
  35                         closed = false;
  36                 }
  37
  38                 /// <summary>
  39                 /// The stream to the filter can use to write write to
  40                 /// </summary>
  41                 protected Stream BaseStream
  42                 {
  43                         get { return baseStream; }
  44                 }
  45
  46                 /// <summary>
  47                 /// This method is not supported for an HttpFilter
  48                 /// </summary>
  49                 /// <exception cref="NotSupportedException">Always thrown</exception>
  50                 public override int Read(byte[] buffer, int offset, int count)
  51                 {
  52                         throw new NotSupportedException();
  53                 }
  54
  55                 /// <summary>
  56                 /// This method is not supported for an HttpFilter
  57                 /// </summary>
  58                 public override bool CanRead
  59                 {
  60                         get { return false; }
  61                 }
  62
  63                 /// <summary>
  64                 /// This method is not supported for an HttpFilter
  65                 /// </summary>
  66                 public override bool CanSeek
  67                 {
  68                         get { return false; }
  69                 }
  70
  71                 /// <summary>
  72                 /// Indicates if the Stream is closed or open
  73                 /// </summary>
  74                 public override bool CanWrite
  75                 {
  76                         get { return !closed; }
  77                 }
  78
  79                 /// <summary>
  80                 /// Close implementation.
  81                 /// </summary>
  82                 /// <remarks>
  83                 /// Don't forget to call base.Close is you override this function.
  84                 /// </remarks>
  85                 public override void Close()
  86                 {
  87                         closed = true;
  88                         baseStream.Close();
  89                 }
  90
  91                 /// <summary>
  92                 /// Indicates if the Stream is closed or open
  93                 /// </summary>
  94                 /// <remarks>
  95                 /// Implementors should always check Closed before writing anything to the BaseStream.
  96                 /// </remarks>
  97                 protected bool Closed
  98                 {
  99                         get { return closed; }
 100                 }
 101
 102                 /// <summary>
 103                 /// This method is not supported for an HttpFilter
 104                 /// </summary>
 105                 /// <exception cref="NotSupportedException">Always thrown</exception>
 106                 public override long Length
 107                 {
 108                         get { throw new NotSupportedException(); }
 109                 }
 110
 111                 /// <summary>
 112                 /// This method is not supported for an HttpFilter
 113                 /// </summary>
 114                 /// <exception cref="NotSupportedException">Always thrown</exception>
 115                 public override long Position
 116                 {
 117                         get { throw new NotSupportedException(); }
 118                         set { throw new NotSupportedException(); }
 119                 }
 120
 121                 /// <summary>
 122                 /// Flushes the base stream
 123                 /// </summary>
 124                 public override void Flush()
 125                 {
 126                         baseStream.Flush();
 127                 }
 128
 129                 /// <summary>
 130                 /// This method is not supported for an HttpFilter
 131                 /// </summary>
 132                 /// <exception cref="NotSupportedException">Always thrown</exception>
 133                 public override long Seek(long offset, SeekOrigin origin)
 134                 {
 135                         throw new NotSupportedException();
 136                 }
 137
 138                 /// <summary>
 139                 /// This method is not supported for an HttpFilter
 140                 /// </summary>
 141                 /// <exception cref="NotSupportedException">Always thrown</exception>
 142                 public override void SetLength(long value)
 143                 {
 144                         throw new NotSupportedException();
 145                 }
 146         }
 147 }