InversionOfControl/Castle.MicroKernel/ModelBuilder/Inspectors/InterceptorInspector.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.ModelBuilder.Inspectors
  16 {
  17         using System;
  18         using System.Configuration;
  19
  20         using Castle.MicroKernel.Util;
  21         using Castle.Core;
  22         using Castle.Core.Configuration;
  23
  24         /// <summary>
  25         /// Inspect the component for <c>InterceptorAttribute</c> and
  26         /// the configuration for the interceptors node
  27         /// </summary>
  28         [Serializable]
  29         public class InterceptorInspector : IContributeComponentModelConstruction
  30         {
  31                 public virtual void ProcessModel(IKernel kernel, ComponentModel model)
  32                 {
  33                         CollectFromAttributes(model);
  34                         CollectFromConfiguration(model);
  35                 }
  36
  37                 protected virtual void CollectFromConfiguration(ComponentModel model)
  38                 {
  39                         if (model.Configuration == null) return;
  40
  41                         IConfiguration interceptors = model.Configuration.Children["interceptors"];
  42
  43                         if (interceptors == null) return;
  44
  45                         foreach(IConfiguration interceptor in interceptors.Children)
  46                         {
  47                                 String value = interceptor.Value;
  48
  49                                 if (!ReferenceExpressionUtil.IsReference(value))
  50                                 {
  51                                         String message = String.Format(
  52                                                 "The value for the interceptor must be a reference " +
  53                                                 "to a component (Currently {0})",
  54                                                 value);
  55
  56                                         throw new ConfigurationErrorsException(message);
  57                                 }
  58
  59                                 InterceptorReference interceptorRef =
  60                                         new InterceptorReference( ReferenceExpressionUtil.ExtractComponentKey(value) );
  61
  62                                 model.Interceptors.Add(interceptorRef);
  63                                 model.Dependencies.Add( CreateDependencyModel(interceptorRef) );
  64                         }
  65                 }
  66
  67                 protected virtual void CollectFromAttributes(ComponentModel model)
  68                 {
  69                         if (!model.Implementation.IsDefined( typeof(InterceptorAttribute), true ))
  70                         {
  71                                 return;
  72                         }
  73
  74                         object[] attributes = model.Implementation.GetCustomAttributes(true);
  75
  76                         foreach(object attribute in attributes)
  77                         {
  78                                 if (attribute is InterceptorAttribute)
  79                                 {
  80                                         InterceptorAttribute attr = (attribute as InterceptorAttribute);
  81
  82                                         AddInterceptor(
  83                                                 attr.Interceptor,
  84                                                 model.Interceptors );
  85
  86                                         model.Dependencies.Add(
  87                                                 CreateDependencyModel(attr.Interceptor) );
  88                                 }
  89                         }
  90                 }
  91
  92                 protected DependencyModel CreateDependencyModel(InterceptorReference interceptor)
  93                 {
  94                         return new DependencyModel(DependencyType.Service, interceptor.ComponentKey,
  95                                 interceptor.ServiceType, false);
  96                 }
  97
  98                 protected void AddInterceptor(InterceptorReference interceptorRef, InterceptorReferenceCollection interceptors)
  99                 {
 100                         interceptors.Add( interceptorRef );
 101                 }
 102         }
 103 }