InversionOfControl/Castle.MicroKernel/SubSystems/Conversion/Converters/ComponentConverter.cs

   1 // Copyright 2004-2008 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.MicroKernel.SubSystems.Conversion
  16 {
  17         using System;
  18
  19         using Castle.MicroKernel.Util;
  20         using Castle.Core;
  21         using Castle.Core.Configuration;
  22
  23         [Serializable]
  24         public class ComponentConverter : AbstractTypeConverter, IKernelDependentConverter
  25         {
  26                 public override bool CanHandleType(Type type, IConfiguration configuration)
  27                 {
  28                         if (configuration.Value != null)
  29                         {
  30                                 return ReferenceExpressionUtil.IsReference(configuration.Value.Trim());
  31                         }
  32                         else
  33                         {
  34                                 return CanHandleType(type);
  35                         }
  36                 }
  37
  38                 public override bool CanHandleType(Type type)
  39                 {
  40                         if (Context.Kernel == null) return false;
  41
  42                         return Context.Kernel.HasComponent(type);
  43                 }
  44
  45                 public override object PerformConversion(String value, Type targetType)
  46                 {
  47                         if (!ReferenceExpressionUtil.IsReference(value))
  48                         {
  49                                 String message = String.Format("Could not convert expression {0} to type {1}. Expecting a reference override like ${some key}", value, targetType.FullName);
  50                                 throw new ConverterException(message);
  51                         }
  52
  53                         String key = ReferenceExpressionUtil.ExtractComponentKey(value);
  54
  55                         DependencyModel dependency = new DependencyModel(DependencyType.ServiceOverride, key, targetType, false);
  56
  57                         return Context.Kernel.Resolver.Resolve(CreationContext.Empty, null, Context.CurrentModel, dependency);
  58                 }
  59
  60                 public override object PerformConversion(IConfiguration configuration, Type targetType)
  61                 {
  62                         return PerformConversion(configuration.Value, targetType);
  63                 }
  64         }
  65 }