InversionOfControl/Castle.MicroKernel/ModelBuilder/Inspectors/ConstructorDependenciesModelInspector.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.Reflection;
  19         using Castle.Core;
  20         using Castle.MicroKernel.SubSystems.Conversion;
  21         using Castle.MicroKernel.Util;
  22
  23         /// <summary>
  24         /// This implementation of <see cref="IContributeComponentModelConstruction"/>
  25         /// collects all available constructors and populates them in the model
  26         /// as candidates. The Kernel will pick up one of the candidates
  27         /// according to a heuristic.
  28         /// </summary>
  29         [Serializable]
  30         public class ConstructorDependenciesModelInspector : IContributeComponentModelConstruction
  31         {
  32                 [NonSerialized]
  33                 private IConversionManager converter;
  34
  35                 public ConstructorDependenciesModelInspector()
  36                 {
  37                 }
  38
  39                 public virtual void ProcessModel(IKernel kernel, ComponentModel model)
  40                 {
  41                         if (converter == null)
  42                         {
  43                                 converter = (IConversionManager)
  44                                             kernel.GetSubSystem(SubSystemConstants.ConversionManagerKey);
  45                         }
  46
  47                         Type targetType = model.Implementation;
  48
  49                         ConstructorInfo[] constructors =
  50                                 targetType.GetConstructors(BindingFlags.Public | BindingFlags.Instance);
  51
  52                         foreach(ConstructorInfo constructor in constructors)
  53                         {
  54                                 // We register each public constructor
  55                                 // and let the ComponentFactory select an
  56                                 // eligible amongst the candidates later
  57                                 model.Constructors.Add(CreateConstructorCandidate(model, constructor));
  58                         }
  59                 }
  60
  61                 protected virtual ConstructorCandidate CreateConstructorCandidate(ComponentModel model, ConstructorInfo constructor)
  62                 {
  63                         ParameterInfo[] parameters = constructor.GetParameters();
  64
  65                         DependencyModel[] dependencies = new DependencyModel[parameters.Length];
  66
  67                         for(int i = 0; i < parameters.Length; i++)
  68                         {
  69                                 ParameterInfo parameter = parameters[i];
  70
  71                                 Type paramType = parameter.ParameterType;
  72
  73                                 // This approach is somewhat problematic. We should use
  74                                 // another strategy to differentiate types and classify dependencies
  75                                 if (converter.IsSupportedAndPrimitiveType(paramType))
  76                                 {
  77                                         dependencies[i] = new DependencyModel(
  78                                                 DependencyType.Parameter, parameter.Name, paramType, false);
  79                                 }
  80                                 else
  81                                 {
  82                                         ParameterModel modelParameter = model.Parameters[parameter.Name];
  83
  84                                         if (modelParameter != null && ReferenceExpressionUtil.IsReference(modelParameter.Value))
  85                                         {
  86                                                 String key = ReferenceExpressionUtil.ExtractComponentKey(modelParameter.Value);
  87
  88                                                 dependencies[i] = new DependencyModel(
  89                                                         DependencyType.ServiceOverride, key, paramType, false);
  90                                         }
  91                                         else
  92                                         {
  93                                                 dependencies[i] = new DependencyModel(
  94                                                         DependencyType.Service, parameter.Name, paramType, false);
  95                                         }
  96                                 }
  97                         }
  98
  99                         return new ConstructorCandidate(constructor, dependencies);
 100                 }
 101         }
 102 }