Components/DictionaryAdapter/Castle.Components.DictionaryAdapter/Attributes/DictionaryAdapterPropertyBinderAttribute.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 using System;
  16
  17 namespace Castle.Components.DictionaryAdapter
  18 {
  19         using System.Collections;
  20
  21         /// <summary>
  22         /// Allows the user to convert the values in the dictionary into a different type on access.
  23         /// </summary>
  24         [AttributeUsage(AttributeTargets.Property, AllowMultiple = false, Inherited = true)]
  25         public class DictionaryAdapterPropertyBinderAttribute :
  26                 DictionaryBehaviorAttribute, IDictionaryPropertyGetter, IDictionaryPropertySetter
  27         {
  28                 private readonly DictionaryAdapterPropertyBinder binder;
  29
  30                 /// <summary>
  31                 /// Specifies a binder to perform conversion between the type currently stored in the
  32                 /// adapted dictionary, and the type the client code wishes to use via the interface.
  33                 /// </summary>
  34                 /// <param name="binderType"></param>
  35                 public DictionaryAdapterPropertyBinderAttribute(Type binderType)
  36                 {
  37                         if (!typeof(DictionaryAdapterPropertyBinder).IsAssignableFrom(binderType))
  38                                 throw new ArgumentException("You may only supply DictionaryAdapterPropertyBinder types to the DictionaryAdapterPropertyBinderAttribute.");
  39
  40                         binder = (DictionaryAdapterPropertyBinder) Activator.CreateInstance(binderType);
  41                 }
  42
  43                 #region IDictionaryPropertyGetter
  44
  45                 object IDictionaryPropertyGetter.GetPropertyValue(
  46                         IDictionaryAdapterFactory factory, IDictionary dictionary,
  47                         string key, object storedValue, PropertyDescriptor property)
  48                 {
  49                         return binder.ConvertFromDictionary(storedValue);
  50                 }
  51
  52                 #endregion
  53
  54                 #region IDictionaryPropertySetter
  55
  56                 bool IDictionaryPropertySetter.SetPropertyValue(
  57                         IDictionaryAdapterFactory factory, IDictionary dictionary,
  58                         string key, ref object value, PropertyDescriptor property)
  59                 {
  60                         value = binder.ConvertFromInterface(value);
  61                         return true;
  62                 }
  63
  64                 #endregion
  65         }
  66 }