InversionOfControl/Castle.MicroKernel/Facilities/FactorySupport/AccessorActivator.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 namespace Castle.Facilities.FactorySupport
  16 {
  17         using System;
  18         using System.Reflection;
  19
  20         using Castle.Core;
  21         using Castle.MicroKernel;
  22         using Castle.MicroKernel.ComponentActivator;
  23         using Castle.MicroKernel.Facilities;
  24
  25
  26         public class AccessorActivator : DefaultComponentActivator
  27         {
  28                 public AccessorActivator(ComponentModel model, IKernel kernel, ComponentInstanceDelegate onCreation, ComponentInstanceDelegate onDestruction) : base(model, kernel, onCreation, onDestruction)
  29                 {
  30                 }
  31
  32                 protected override object Instantiate(CreationContext context)
  33                 {
  34                         String accessor = (String) Model.ExtendedProperties["instance.accessor"];
  35
  36                         PropertyInfo pi = Model.Implementation.GetProperty(
  37                                 accessor, BindingFlags.Public|BindingFlags.Static );
  38
  39                         if (pi == null)
  40                         {
  41                                 String message = String.Format("You have specified an instance accessor " +
  42                                         "for the component '{0}' {1} which could not be found (no public " +
  43                                         "static property has this name)", Model.Name, Model.Implementation.FullName);
  44                                 throw new FacilityException(message);
  45                         }
  46
  47                         if (!pi.CanRead)
  48                         {
  49                                 String message = String.Format("You have specified an instance accessor " +
  50                                         "for the component '{0}' {1} which is write-only",
  51                                         Model.Name, Model.Implementation.FullName);
  52                                 throw new FacilityException(message);
  53                         }
  54
  55                         try
  56                         {
  57                                 return pi.GetValue( null, new object[0] );
  58                         }
  59                         catch(Exception ex)
  60                         {
  61                                 String message = String.Format("The instance accessor " +
  62                                         "invocation failed for '{0}' {1}",
  63                                         Model.Name, Model.Implementation.FullName);
  64                                 throw new FacilityException(message, ex);
  65                         }
  66                 }
  67         }
  68 }