mcs/class/corlib/System/Attribute.cs

   1 //\r
   2 // System.Attribute.cs\r
   3 //\r
   4 // Authors:\r
   5 //   Miguel de Icaza (miguel@ximian.com) - Original\r
   6 //   Nick D. Drochak II (ndrochak@gol.com) - Implemented most of the guts\r
   7 //\r
   8 // (C) Ximian, Inc.  http://www.ximian.com\r
   9 //\r
  10 \r
  11 using System;\r
  12 namespace System {\r
  13 \r
  14         public abstract class Attribute {\r
  15 \r
  16                 protected Attribute ()\r
  17                 {\r
  18                 }\r
  19 \r
  20                 public virtual object TypeId {\r
  21                         get {\r
  22                                 // Derived classes should override this default behaviour as appropriate\r
  23                                 return this.GetType();\r
  24                         }\r
  25                 }\r
  26 \r
  27                 private static void CheckParameters(object element, Type attributeType)\r
  28                 {\r
  29                         // neither parameter is allowed to be null\r
  30                         if (null == element) \r
  31                         {\r
  32                                 throw new ArgumentNullException("element");\r
  33                         }\r
  34 \r
  35                         if (null == attributeType) \r
  36                         {\r
  37                                 throw new ArgumentNullException("attributeType");\r
  38                         }\r
  39 \r
  40                 }\r
  41 \r
  42                 private static System.Attribute FindAttribute(object[] attributes)\r
  43                 {\r
  44                         // if there exists more than one attribute of the given type, throw an exception\r
  45                         if (attributes.Length > 1) \r
  46                         {\r
  47                                 throw new System.Reflection.AmbiguousMatchException("<element> has more than one attribute of type <attributeType>");\r
  48                         }\r
  49 \r
  50                         if (attributes.Length < 1) \r
  51                         {\r
  52                                 return (System.Attribute) null;\r
  53                         }\r
  54 \r
  55                         // tested above for '> 1' and and '< 1', so only '== 1' is left, i.e. we found the attribute\r
  56                         return (System.Attribute) attributes[0];\r
  57                 }\r
  58 \r
  59                 private static void CheckAncestry(Type attributeType)\r
  60                 {\r
  61                         // attributeType must be derived from type System.Attribute\r
  62                         Type t = typeof(System.Attribute);\r
  63                         \r
  64                         /* fixme: thgi does not work for target monolib2\r
  65                         if (!attributeType.IsSubclassOf(t))\r
  66                         {\r
  67                                 throw new ArgumentException("Parameter is not a type derived from System.Attribute", "attributeType");\r
  68                         }\r
  69                         */\r
  70                 }\r
  71 \r
  72                 public static Attribute GetCustomAttribute(System.Reflection.ParameterInfo element, Type attributeType){\r
  73                         return GetCustomAttribute(element, attributeType, true);\r
  74                 }\r
  75 \r
  76                 public static Attribute GetCustomAttribute(System.Reflection.MemberInfo element, Type attributeType){\r
  77                         return GetCustomAttribute(element, attributeType, true);\r
  78                 }\r
  79 \r
  80                 public static Attribute GetCustomAttribute(System.Reflection.Assembly element, Type attributeType){                     return GetCustomAttribute(element, attributeType, true);\r
  81                 }\r
  82 \r
  83                 public static Attribute GetCustomAttribute(System.Reflection.Module element, Type attributeType){\r
  84                         return GetCustomAttribute(element, attributeType, true);\r
  85                 }\r
  86 \r
  87                 public static Attribute GetCustomAttribute(System.Reflection.Module element, Type attributeType, bool inherit){\r
  88                         // neither parameter is allowed to be null\r
  89                         CheckParameters(element, attributeType);\r
  90 \r
  91                         // attributeType must be derived from type System.Attribute\r
  92                         CheckAncestry(attributeType);\r
  93 \r
  94                         // Module inheritance hierarchies CAN NOT be searched for attributes, so the second\r
  95                         // parameter of GetCustomAttributes() is INGNORED.\r
  96                         object[] attributes = element.GetCustomAttributes(attributeType, inherit);\r
  97 \r
  98                         return FindAttribute(attributes);\r
  99                 }\r
 100 \r
 101                 public static Attribute GetCustomAttribute(System.Reflection.Assembly element, Type attributeType, bool inherit){\r
 102                         // neither parameter is allowed to be null\r
 103                         CheckParameters(element, attributeType);\r
 104 \r
 105                         // attributeType must be derived from type System.Attribute\r
 106                         CheckAncestry(attributeType);\r
 107 \r
 108                         // Assembly inheritance hierarchies CAN NOT be searched for attributes, so the second\r
 109                         // parameter of GetCustomAttributes() is INGNORED.\r
 110                         object[] attributes = element.GetCustomAttributes(attributeType, inherit);\r
 111 \r
 112                         return FindAttribute(attributes);\r
 113                 }\r
 114                 public static Attribute GetCustomAttribute(System.Reflection.ParameterInfo element, Type attributeType, bool inherit){\r
 115                         // neither parameter is allowed to be null\r
 116                         CheckParameters(element, attributeType);\r
 117 \r
 118                         // attributeType must be derived from type System.Attribute\r
 119                         CheckAncestry(attributeType);\r
 120 \r
 121                         // ParameterInfo inheritance hierarchies CAN NOT be searched for attributes, so the second\r
 122                         // parameter of GetCustomAttributes() is INGNORED.\r
 123                         object[] attributes = element.GetCustomAttributes(attributeType, inherit);\r
 124 \r
 125                         return FindAttribute(attributes);\r
 126                 }\r
 127                 public static Attribute GetCustomAttribute(System.Reflection.MemberInfo element, Type attributeType, bool inherit){\r
 128                         // neither parameter is allowed to be null\r
 129                         CheckParameters(element, attributeType);\r
 130 \r
 131                         // attributeType must be derived from type System.Attribute\r
 132                         CheckAncestry(attributeType);\r
 133 \r
 134                         // MemberInfo inheritance hierarchies can be searched for attributes, so the second\r
 135                         // parameter of GetCustomAttributes() is respected.\r
 136                         object[] attributes = element.GetCustomAttributes(attributeType, inherit);\r
 137 \r
 138                         return FindAttribute(attributes);\r
 139                 }\r
 140 \r
 141                 public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element){\r
 142                         return System.Attribute.GetCustomAttributes(element, true);\r
 143                 }\r
 144                 public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element){\r
 145                         return System.Attribute.GetCustomAttributes(element, true);\r
 146                 }\r
 147                 public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element){\r
 148                         return System.Attribute.GetCustomAttributes(element, true);\r
 149                 }\r
 150                 public static Attribute[] GetCustomAttributes(System.Reflection.Module element){\r
 151                         return System.Attribute.GetCustomAttributes(element, true);\r
 152                 }\r
 153                 public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, Type attributeType){\r
 154                         return System.Attribute.GetCustomAttributes(element, attributeType, true);\r
 155                 }\r
 156                 public static Attribute[] GetCustomAttributes(System.Reflection.Module element, Type attributeType){\r
 157                         return System.Attribute.GetCustomAttributes(element, attributeType, true);\r
 158                 }\r
 159                 public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, Type attributeType){\r
 160                         return System.Attribute.GetCustomAttributes(element, attributeType, true);\r
 161                 }\r
 162                 public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, Type attributeType)\r
 163                 {\r
 164                         return System.Attribute.GetCustomAttributes(element, attributeType, true);\r
 165                 }\r
 166                 public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, Type attributeType, bool inherit)\r
 167                 {\r
 168                         // element parameter is not allowed to be null\r
 169                         CheckParameters(element, attributeType);\r
 170 \r
 171                         // make a properly typed array to return containing the custom attributes\r
 172                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(attributeType, inherit);\r
 173 \r
 174                         return attributes;\r
 175                 }\r
 176                 public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, Type attributeType, bool inherit){\r
 177                         // element parameter is not allowed to be null\r
 178                         CheckParameters(element, attributeType);\r
 179 \r
 180                         // make a properly typed array to return containing the custom attributes\r
 181                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(attributeType, inherit);\r
 182 \r
 183                         return attributes;\r
 184                 }\r
 185                 public static Attribute[] GetCustomAttributes(System.Reflection.Module element, Type attributeType, bool inherit){\r
 186                         // element parameter is not allowed to be null\r
 187                         CheckParameters(element, attributeType);\r
 188 \r
 189                         // make a properly typed array to return containing the custom attributes\r
 190                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(attributeType, inherit);\r
 191 \r
 192                         return attributes;\r
 193                 }\r
 194                 public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, Type attributeType, bool inherit)\r
 195                 {\r
 196                         // element parameter is not allowed to be null\r
 197                         CheckParameters(element, attributeType);\r
 198 \r
 199                         // make a properly typed array to return containing the custom attributes\r
 200                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(attributeType, inherit);\r
 201 \r
 202                         return attributes;\r
 203                 }\r
 204                 public static Attribute[] GetCustomAttributes(System.Reflection.Module element, bool inherit)\r
 205                 {\r
 206                         // element parameter is not allowed to be null\r
 207                         CheckParameters(element, typeof(System.Attribute));\r
 208 \r
 209                         // make a properly typed array to return containing the custom attributes\r
 210                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(inherit);\r
 211 \r
 212                         return attributes;\r
 213                 }\r
 214                 public static Attribute[] GetCustomAttributes(System.Reflection.Assembly element, bool inherit){\r
 215                         // element parameter is not allowed to be null\r
 216                         CheckParameters(element, typeof(System.Attribute));\r
 217 \r
 218                         // make a properly typed array to return containing the custom attributes\r
 219                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(inherit);\r
 220 \r
 221                         return attributes;\r
 222                 }\r
 223                 public static Attribute[] GetCustomAttributes(System.Reflection.MemberInfo element, bool inherit){\r
 224                         // element parameter is not allowed to be null\r
 225                         CheckParameters(element, typeof(System.Attribute));\r
 226 \r
 227                         // make a properly typed array to return containing the custom attributes\r
 228                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(inherit);\r
 229 \r
 230                         return attributes;\r
 231                 }\r
 232                 public static Attribute[] GetCustomAttributes(System.Reflection.ParameterInfo element, bool inherit){\r
 233                         // element parameter is not allowed to be null\r
 234                         CheckParameters(element, typeof(System.Attribute));\r
 235 \r
 236                         // make a properly typed array to return containing the custom attributes\r
 237                         System.Attribute[] attributes = (System.Attribute[]) element.GetCustomAttributes(inherit);\r
 238 \r
 239                         return attributes;\r
 240                 }\r
 241 \r
 242                 public override int GetHashCode(){\r
 243                         // TODO: Implement me\r
 244                         return 0;\r
 245                 }\r
 246                 \r
 247                 public virtual bool IsDefaultAttribute(){\r
 248                         // Derived classes should override this default behaviour as appropriate\r
 249                         return false;\r
 250                 }\r
 251                 \r
 252                 public static bool IsDefined(System.Reflection.Module element, Type attributeType){\r
 253                         return (System.Attribute.GetCustomAttributes(element, attributeType).Length > 0);\r
 254                 }\r
 255                 public static bool IsDefined(System.Reflection.ParameterInfo element, Type attributeType){\r
 256                         return (System.Attribute.GetCustomAttributes(element, attributeType).Length > 0);\r
 257                 }\r
 258                 public static bool IsDefined(System.Reflection.MemberInfo element, Type attributeType){\r
 259                         return (System.Attribute.GetCustomAttributes(element, attributeType).Length > 0);\r
 260                 }\r
 261                 public static bool IsDefined(System.Reflection.Assembly element, Type attributeType){\r
 262                         return (System.Attribute.GetCustomAttributes(element, attributeType).Length > 0);\r
 263                 }\r
 264                 public static bool IsDefined(System.Reflection.MemberInfo element, Type attributeType, bool inherit){\r
 265                         return (System.Attribute.GetCustomAttributes(element, attributeType, inherit).Length > 0);\r
 266                 }\r
 267                 public static bool IsDefined(System.Reflection.Assembly element, Type attributeType, bool inherit){\r
 268                         return (System.Attribute.GetCustomAttributes(element, attributeType, inherit).Length > 0);\r
 269                 }\r
 270                 public static bool IsDefined(System.Reflection.Module element, Type attributeType, bool inherit){\r
 271                         return (System.Attribute.GetCustomAttributes(element, attributeType, inherit).Length > 0);\r
 272                 }\r
 273                 public static bool IsDefined(System.Reflection.ParameterInfo element, Type attributeType, bool inherit){\r
 274                         return (System.Attribute.GetCustomAttributes(element, attributeType, inherit).Length > 0);\r
 275                 }\r
 276                 \r
 277                 public virtual bool Match(object obj){\r
 278                         // default action is the same as Equals.  Derived classes should override as appropriate\r
 279                         return this.Equals(obj);\r
 280                 }\r
 281 \r
 282         }\r
 283 \r
 284 }\r