mcs/class/System.Web.Mvc/System.Web.Mvc/ViewUserControl.cs

   1 /* ****************************************************************************\r
   2  *\r
   3  * Copyright (c) Microsoft Corporation. All rights reserved.\r
   4  *\r
   5  * This software is subject to the Microsoft Public License (Ms-PL). \r
   6  * A copy of the license can be found in the license.htm file included \r
   7  * in this distribution.\r
   8  *\r
   9  * You must not remove this notice, or any other, from this software.\r
  10  *\r
  11  * ***************************************************************************/\r
  12 \r
  13 namespace System.Web.Mvc {\r
  14     using System;\r
  15     using System.ComponentModel;\r
  16     using System.Diagnostics.CodeAnalysis;\r
  17     using System.Globalization;\r
  18     using System.Web.Mvc.Resources;\r
  19     using System.Web.UI;\r
  20 \r
  21     [FileLevelControlBuilder(typeof(ViewUserControlControlBuilder))]\r
  22     public class ViewUserControl : UserControl, IViewDataContainer {\r
  23         private AjaxHelper _ajaxHelper;\r
  24         private HtmlHelper _htmlHelper;\r
  25         private ViewContext _viewContext;\r
  26         private ViewDataDictionary _viewData;\r
  27         private string _viewDataKey;\r
  28 \r
  29         public AjaxHelper Ajax {\r
  30             get {\r
  31                 if (_ajaxHelper == null) {\r
  32                     _ajaxHelper = new AjaxHelper(ViewContext, this);\r
  33                 }\r
  34                 return _ajaxHelper;\r
  35             }\r
  36         }\r
  37 \r
  38         public HtmlHelper Html {\r
  39             get {\r
  40                 if (_htmlHelper == null) {\r
  41                     _htmlHelper = new HtmlHelper(ViewContext, this);\r
  42                 }\r
  43                 return _htmlHelper;\r
  44             }\r
  45         }\r
  46 \r
  47         public object Model {\r
  48             get {\r
  49                 return ViewData.Model;\r
  50             }\r
  51         }\r
  52 \r
  53         public TempDataDictionary TempData {\r
  54             get {\r
  55                 return ViewPage.TempData;\r
  56             }\r
  57         }\r
  58 \r
  59         public UrlHelper Url {\r
  60             get {\r
  61                 return ViewPage.Url;\r
  62             }\r
  63         }\r
  64 \r
  65         [Browsable(false)]\r
  66         [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]\r
  67         public ViewContext ViewContext {\r
  68             get {\r
  69                 return _viewContext ?? ViewPage.ViewContext;\r
  70             }\r
  71             set {\r
  72                 _viewContext = value;\r
  73             }\r
  74         }\r
  75 \r
  76         [SuppressMessage("Microsoft.Usage", "CA2227:CollectionPropertiesShouldBeReadOnly",\r
  77             Justification = "This is the mechanism by which the ViewUserControl gets its ViewDataDictionary object.")]\r
  78         [Browsable(false)]\r
  79         [DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)]\r
  80         public ViewDataDictionary ViewData {\r
  81             get {\r
  82                 EnsureViewData();\r
  83                 return _viewData;\r
  84             }\r
  85             set {\r
  86                 SetViewData(value);\r
  87             }\r
  88         }\r
  89 \r
  90         [DefaultValue("")]\r
  91         public string ViewDataKey {\r
  92             get {\r
  93                 return _viewDataKey ?? String.Empty;\r
  94             }\r
  95             set {\r
  96                 _viewDataKey = value;\r
  97             }\r
  98         }\r
  99 \r
 100         internal ViewPage ViewPage {\r
 101             get {\r
 102                 ViewPage viewPage = Page as ViewPage;\r
 103                 if (viewPage == null) {\r
 104                     throw new InvalidOperationException(MvcResources.ViewUserControl_RequiresViewPage);\r
 105                 }\r
 106                 return viewPage;\r
 107             }\r
 108         }\r
 109 \r
 110         public HtmlTextWriter Writer {\r
 111             get {\r
 112                 return ViewPage.Writer;\r
 113             }\r
 114         }\r
 115 \r
 116         protected virtual void SetViewData(ViewDataDictionary viewData) {\r
 117             _viewData = viewData;\r
 118         }\r
 119 \r
 120         protected void EnsureViewData() {\r
 121             if (_viewData != null) {\r
 122                 return;\r
 123             }\r
 124 \r
 125             // Get the ViewData for this ViewUserControl, optionally using the specified ViewDataKey\r
 126             IViewDataContainer vdc = GetViewDataContainer(this);\r
 127             if (vdc == null) {\r
 128                 throw new InvalidOperationException(\r
 129                     String.Format(\r
 130                         CultureInfo.CurrentUICulture,\r
 131                         MvcResources.ViewUserControl_RequiresViewDataProvider,\r
 132                         AppRelativeVirtualPath));\r
 133             }\r
 134 \r
 135             ViewDataDictionary myViewData = vdc.ViewData;\r
 136 \r
 137             // If we have a ViewDataKey, try to extract the ViewData from the dictionary, otherwise\r
 138             // return the container's ViewData.\r
 139             if (!String.IsNullOrEmpty(ViewDataKey)) {\r
 140                 object target = myViewData.Eval(ViewDataKey);\r
 141                 myViewData = target as ViewDataDictionary ?? new ViewDataDictionary(myViewData) { Model = target };\r
 142             }\r
 143 \r
 144             SetViewData(myViewData);\r
 145         }\r
 146 \r
 147         private static IViewDataContainer GetViewDataContainer(Control control) {\r
 148             // Walk up the control hierarchy until we find someone that implements IViewDataContainer\r
 149             while (control != null) {\r
 150                 control = control.Parent;\r
 151                 IViewDataContainer vdc = control as IViewDataContainer;\r
 152                 if (vdc != null) {\r
 153                     return vdc;\r
 154                 }\r
 155             }\r
 156             return null;\r
 157         }\r
 158 \r
 159         public virtual void RenderView(ViewContext viewContext) {\r
 160             // TODO: Remove this hack. Without it, the browser appears to always load cached output\r
 161             viewContext.HttpContext.Response.Cache.SetExpires(DateTime.Now);\r
 162             ViewUserControlContainerPage containerPage = new ViewUserControlContainerPage(this);\r
 163             // Tracing requires Page IDs to be unique.\r
 164             ID = Guid.NewGuid().ToString();\r
 165 \r
 166             RenderViewAndRestoreContentType(containerPage, viewContext);\r
 167         }\r
 168 \r
 169         internal static void RenderViewAndRestoreContentType(ViewPage containerPage, ViewContext viewContext) {\r
 170             // We need to restore the Content-Type since Page.SetIntrinsics() will reset it. It's not possible\r
 171             // to work around the call to SetIntrinsics() since the control's render method requires the\r
 172             // containing page's Response property to be non-null, and SetIntrinsics() is the only way to set\r
 173             // this.\r
 174             string savedContentType = viewContext.HttpContext.Response.ContentType;\r
 175             containerPage.RenderView(viewContext);\r
 176             viewContext.HttpContext.Response.ContentType = savedContentType;\r
 177         }\r
 178 \r
 179         private sealed class ViewUserControlContainerPage : ViewPage {\r
 180             public ViewUserControlContainerPage(ViewUserControl userControl) {\r
 181                 Controls.Add(userControl);\r
 182             }\r
 183         }\r
 184     }\r
 185 }\r