InversionOfControl/Castle.MicroKernel/ComponentActivator/WebUserControlComponentActivator.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 #if !MONO
  16
  17 namespace Castle.MicroKernel.ComponentActivator
  18 {
  19         using System;
  20         using System.Web;
  21         using System.Web.UI;
  22         using Castle.Core;
  23
  24         /// <summary>
  25         /// Attempts to dynamically load a UserControl by invoking Page.LoadControl.
  26         /// There are two uses of this class.
  27         /// <para>
  28         /// 1) Add a component to the Kernel and add a VirtualPath attribute specifying
  29         /// the relative path of the .ascx file for the associated UserControl. (easy)
  30         /// </para>
  31         /// <example>
  32         ///   <code>
  33         ///     &lt;component id="BasketView"
  34         ///       service="Castle.ShoppingCart.IBasketView, Castle.ShoppingCart"
  35         ///       type="Castle.ShoppingCart.BasketView, Castle.ShoppingCart"
  36         ///       lifestyle="transient"
  37         ///       virtualPath="~/Views/BasketView.ascx"
  38         ///     /&gt;
  39         ///   </code>
  40         /// </example>
  41         /// <para>
  42         /// 2) Precompile a UserControl and add the pre-compiled class to the Kernel. (hard)
  43         /// Has not been tested with proxies.
  44         /// </para>
  45         /// </summary>
  46         [Serializable]
  47         public class WebUserControlComponentActivator : DefaultComponentActivator
  48         {
  49                 /// <summary>
  50                 /// Initializes a new instance of the <see cref="WebUserControlComponentActivator"/> class.
  51                 /// </summary>
  52                 /// <param name="model">The model.</param>
  53                 /// <param name="kernel">The kernel.</param>
  54                 /// <param name="onCreation">The on creation.</param>
  55                 /// <param name="onDestruction">The on destruction.</param>
  56                 public WebUserControlComponentActivator(ComponentModel model, IKernel kernel,
  57                                                                                                 ComponentInstanceDelegate onCreation,
  58                                                         ComponentInstanceDelegate onDestruction)
  59                         : base(model, kernel, onCreation, onDestruction)
  60                 {
  61                 }
  62
  63                 /// <summary>
  64                 /// Creates the instance.
  65                 /// </summary>
  66                 /// <param name="context">The context.</param>
  67                 /// <param name="arguments">The arguments.</param>
  68                 /// <param name="signature">The signature.</param>
  69                 /// <returns></returns>
  70                 protected override object CreateInstance(CreationContext context, object[] arguments, Type[] signature)
  71                 {
  72                         object instance = null;
  73
  74                         Type implType = Model.Implementation;
  75
  76                         bool createProxy = Model.Interceptors.HasInterceptors;
  77                         bool createInstance = true;
  78
  79                         if (createProxy)
  80                         {
  81                                 createInstance = Kernel.ProxyFactory.RequiresTargetInstance(Kernel, Model);
  82                         }
  83
  84                         if (createInstance)
  85                         {
  86                                 try
  87                                 {
  88                                         HttpContext currentContext = HttpContext.Current;
  89                                         if (currentContext == null)
  90                                         {
  91                                                 throw new InvalidOperationException(
  92                                                         "System.Web.HttpContext.Current is null.  WebUserControlComponentActivator can only be used in an ASP.Net environment.");
  93                                         }
  94
  95                                         Page currentPage = currentContext.Handler as Page;
  96                                         if (currentPage == null)
  97                                         {
  98                                                 throw new InvalidOperationException("System.Web.HttpContext.Current.Handler is not of type System.Web.UI.Page");
  99                                         }
 100
 101                                         string virtualPath = Model.Configuration.Attributes["VirtualPath"];
 102                                         if (!string.IsNullOrEmpty(virtualPath))
 103                                         {
 104                                                 instance = currentPage.LoadControl(virtualPath);
 105                                         }
 106                                         else
 107                                         {
 108                                                 instance = currentPage.LoadControl(implType, arguments);
 109                                         }
 110                                 }
 111                                 catch(Exception ex)
 112                                 {
 113                                         throw new ComponentActivatorException(
 114                                                 "WebUserControlComponentActivator: could not instantiate " + Model.Implementation.FullName, ex);
 115                                 }
 116                         }
 117
 118                         if (createProxy)
 119                         {
 120                                 try
 121                                 {
 122                                         instance = Kernel.ProxyFactory.Create(Kernel, instance, Model, arguments);
 123                                 }
 124                                 catch(Exception ex)
 125                                 {
 126                                         throw new ComponentActivatorException("ComponentActivator: could not proxy " + Model.Implementation.FullName, ex);
 127                                 }
 128                         }
 129
 130                         return instance;
 131                 }
 132         }
 133 }
 134
 135 #endif