mcs/class/System.Net.Http/System.Net.Http.Headers/HeaderInfo.cs

   1 //
   2 // HeaderInfo.cs
   3 //
   4 // Authors:
   5 //      Marek Safar  <marek.safar@gmail.com>
   6 //
   7 // Copyright (C) 2011, 2014 Xamarin Inc (http://www.xamarin.com)
   8 //
   9 // Permission is hereby granted, free of charge, to any person obtaining
  10 // a copy of this software and associated documentation files (the
  11 // "Software"), to deal in the Software without restriction, including
  12 // without limitation the rights to use, copy, modify, merge, publish,
  13 // distribute, sublicense, and/or sell copies of the Software, and to
  14 // permit persons to whom the Software is furnished to do so, subject to
  15 // the following conditions:
  16 //
  17 // The above copyright notice and this permission notice shall be
  18 // included in all copies or substantial portions of the Software.
  19 //
  20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  27 //
  28
  29 using System.Diagnostics;
  30 using System.Collections.Generic;
  31
  32 namespace System.Net.Http.Headers
  33 {
  34         delegate bool TryParseDelegate<T> (string value, out T result);
  35         delegate bool TryParseListDelegate<T> (string value, int minimalCount, out List<T> result);
  36
  37         abstract class HeaderInfo
  38         {
  39                 class HeaderTypeInfo<T, U> : HeaderInfo where U : class
  40                 {
  41                         readonly TryParseDelegate<T> parser;
  42
  43                         public HeaderTypeInfo (string name, TryParseDelegate<T> parser, HttpHeaderKind headerKind)
  44                                 : base (name, headerKind)
  45                         {
  46                                 this.parser = parser;
  47                         }
  48
  49                         public override void AddToCollection (object collection, object value)
  50                         {
  51                                 Debug.Assert (AllowsMany);
  52
  53                                 var c = (HttpHeaderValueCollection<U>) collection;
  54
  55                                 var list = value as List<U>;
  56                                 if (list != null)
  57                                         c.AddRange (list);
  58                                 else
  59                                         c.Add ((U) value);
  60                         }
  61
  62                         protected override object CreateCollection (HttpHeaders headers, HeaderInfo headerInfo)
  63                         {
  64                                 return new HttpHeaderValueCollection<U> (headers, headerInfo);
  65                         }
  66
  67                         public override List<string> ToStringCollection (object collection)
  68                         {
  69                                 if (collection == null)
  70                                         return null;
  71
  72                                 var c = (HttpHeaderValueCollection<U>) collection;
  73                                 if (c.Count == 0)
  74                                         return null;
  75
  76                                 var list = new List<string> ();
  77                                 foreach (var item in c) {
  78                                         list.Add (item.ToString ());
  79                                 }
  80
  81                                 return list;
  82                         }
  83
  84                         public override bool TryParse (string value, out object result)
  85                         {
  86                                 T tresult;
  87                                 bool b = parser (value, out tresult);
  88                                 result = tresult;
  89                                 return b;
  90                         }
  91                 }
  92
  93                 class CollectionHeaderTypeInfo<T, U> : HeaderTypeInfo<T, U> where U : class
  94                 {
  95                         readonly int minimalCount;
  96                         readonly string separator;
  97                         readonly TryParseListDelegate<T> parser;
  98
  99                         public CollectionHeaderTypeInfo (string name, TryParseListDelegate<T> parser, HttpHeaderKind headerKind, int minimalCount, string separator)
 100                                 : base (name, null, headerKind)
 101                         {
 102                                 this.parser = parser;
 103                                 this.minimalCount = minimalCount;
 104                                 AllowsMany = true;
 105                                 this.separator = separator;
 106                         }
 107
 108                         public override string Separator {
 109                                 get {
 110                                         return separator;
 111                                 }
 112                         }
 113
 114                         public override bool TryParse (string value, out object result)
 115                         {
 116                                 List<T> tresult;
 117                                 if (!parser (value, minimalCount, out tresult)) {
 118                                         result = null;
 119                                         return false;
 120                                 }
 121
 122                                 result = tresult;
 123                                 return true;
 124                         }
 125                 }
 126
 127                 public bool AllowsMany;
 128                 public readonly HttpHeaderKind HeaderKind;
 129                 public readonly string Name;
 130
 131                 protected HeaderInfo (string name, HttpHeaderKind headerKind)
 132                 {
 133                         this.Name = name;
 134                         this.HeaderKind = headerKind;
 135                 }
 136
 137                 public static HeaderInfo CreateSingle<T> (string name, TryParseDelegate<T> parser, HttpHeaderKind headerKind, Func<object, string> toString = null)
 138                 {
 139                         return new HeaderTypeInfo<T, object> (name, parser, headerKind) {
 140                                 CustomToString = toString
 141                         };
 142                 }
 143
 144                 //
 145                 // Headers with #rule for defining lists of elements or *rule for defining occurences of elements
 146                 //
 147                 public static HeaderInfo CreateMulti<T> (string name, TryParseListDelegate<T> elementParser, HttpHeaderKind headerKind, int minimalCount = 1, string separator = ", ") where T : class
 148                 {
 149                         return new CollectionHeaderTypeInfo<T, T> (name, elementParser, headerKind, minimalCount, separator);
 150                 }
 151
 152                 public object CreateCollection (HttpHeaders headers)
 153                 {
 154                         return CreateCollection (headers, this);
 155                 }
 156
 157                 public Func<object, string> CustomToString {
 158                         get; private set;
 159                 }
 160
 161                 public virtual string Separator {
 162                         get {
 163                                 // Needed for AllowsMany only
 164                                 throw new NotSupportedException ();
 165                         }
 166                 }
 167
 168                 public abstract void AddToCollection (object collection, object value);
 169                 protected abstract object CreateCollection (HttpHeaders headers, HeaderInfo headerInfo);
 170                 public abstract List<string> ToStringCollection (object collection);
 171                 public abstract bool TryParse (string value, out object result);
 172         }
 173 }