mcs/class/System.Web.Mvc3/Mvc/FilterAttribute.cs

   1 namespace System.Web.Mvc {
   2     using System;
   3     using System.Collections.Concurrent;
   4     using System.Linq;
   5     using System.Web.Mvc.Resources;
   6
   7     [AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
   8     public abstract class FilterAttribute : Attribute, IMvcFilter {
   9         private readonly static ConcurrentDictionary<Type, bool> _multiuseAttributeCache = new ConcurrentDictionary<Type, bool>();
  10         private int _order = Filter.DefaultOrder;
  11
  12         private static bool AllowsMultiple(Type attributeType) {
  13             return _multiuseAttributeCache.GetOrAdd(
  14                 attributeType,
  15                 type => type.GetCustomAttributes(typeof(AttributeUsageAttribute), true)
  16                             .Cast<AttributeUsageAttribute>()
  17                             .First()
  18                             .AllowMultiple
  19             );
  20         }
  21
  22         public bool AllowMultiple {
  23             get {
  24                 return AllowsMultiple(GetType());
  25             }
  26         }
  27
  28         public int Order {
  29             get {
  30                 return _order;
  31             }
  32             set {
  33                 if (value < Filter.DefaultOrder) {
  34                     throw new ArgumentOutOfRangeException("value", MvcResources.FilterAttribute_OrderOutOfRange);
  35                 }
  36                 _order = value;
  37             }
  38         }
  39     }
  40 }