mcs/class/System.Web/System.Web.UI.WebControls/HierarchicalDataBoundControl.cs

   1 //
   2 // System.Web.UI.WebControls.HierarchicalDataBoundControl.cs
   3 //
   4 // Authors:
   5 //      Lluis Sanchez Gual (lluis@novell.com)
   6 //
   7 // (C) 2004 Novell, Inc (http://www.novell.com)
   8 //
   9
  10 //
  11 // Permission is hereby granted, free of charge, to any person obtaining
  12 // a copy of this software and associated documentation files (the
  13 // "Software"), to deal in the Software without restriction, including
  14 // without limitation the rights to use, copy, modify, merge, publish,
  15 // distribute, sublicense, and/or sell copies of the Software, and to
  16 // permit persons to whom the Software is furnished to do so, subject to
  17 // the following conditions:
  18 //
  19 // The above copyright notice and this permission notice shall be
  20 // included in all copies or substantial portions of the Software.
  21 //
  22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  29 //
  30
  31 #if NET_2_0
  32 using System.Collections;
  33 using System.ComponentModel;
  34 using System.Web.UI;
  35 using System.Web.UI.WebControls.Adapters;
  36
  37 namespace System.Web.UI.WebControls
  38 {
  39         [DesignerAttribute ("System.Web.UI.Design.WebControls.HierarchicalDataBoundControlDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
  40         public abstract class HierarchicalDataBoundControl : BaseDataBoundControl
  41         {
  42                 [IDReferencePropertyAttribute (typeof(HierarchicalDataSourceControl))]
  43                 public override string DataSourceID {
  44                         get {
  45                                 object o = ViewState ["DataSourceID"];
  46                                 if (o != null)
  47                                         return (string)o;
  48
  49                                 return String.Empty;
  50                         }
  51                         set {
  52                                 if (Initialized)
  53                                         RequiresDataBinding = true;
  54
  55                                 ViewState ["DataSourceID"] = value;
  56                         }
  57                 }
  58
  59                 protected virtual HierarchicalDataSourceView GetData (string viewPath)
  60                 {
  61                         if (DataSource != null && DataSourceID != "")
  62                                 throw new HttpException ();
  63                         IHierarchicalDataSource ds = GetDataSource ();
  64                         if (ds != null)
  65                                 return ds.GetHierarchicalView (viewPath);
  66
  67                         if (DataSource is IHierarchicalEnumerable)
  68                                 return new ReadOnlyDataSourceView ((IHierarchicalEnumerable) DataSource);
  69
  70                         return null;
  71                 }
  72
  73                 protected virtual IHierarchicalDataSource GetDataSource ()
  74                 {
  75                         if (IsBoundUsingDataSourceID) {
  76                                 Control ctrl = FindDataSource ();
  77
  78                                 if (ctrl == null)
  79                                         throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
  80                                 if (!(ctrl is IHierarchicalDataSource))
  81                                         throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IHierarchicalDataSource.", DataSourceID));
  82                                 return (IHierarchicalDataSource) ctrl;
  83                         }
  84
  85                         return DataSource as IHierarchicalDataSource;
  86                 }
  87
  88                 bool IsDataBound {
  89                         get {
  90                                 return ViewState.GetBool ("DataBound", false);
  91                         }
  92                         set {
  93                                 ViewState ["DataBound"] = value;
  94                         }
  95                 }
  96
  97                 protected void MarkAsDataBound ()
  98                 {
  99                         IsDataBound = true;
 100                 }
 101
 102                 protected override void OnDataPropertyChanged ()
 103                 {
 104                         RequiresDataBinding = true;
 105                 }
 106
 107                 protected virtual void OnDataSourceChanged (object sender, EventArgs e)
 108                 {
 109                         RequiresDataBinding = true;
 110                 }
 111
 112                 protected internal override void OnLoad (EventArgs e)
 113                 {
 114                         if (!Initialized) {
 115                                 Initialize ();
 116                                 ConfirmInitState ();
 117                         }
 118
 119                         base.OnLoad(e);
 120                 }
 121
 122                 void Initialize ()
 123                 {
 124                         if (!Page.IsPostBack || (IsViewStateEnabled && !IsDataBound))
 125                                 RequiresDataBinding = true;
 126
 127                         IHierarchicalDataSource ds = GetDataSource ();
 128                         if (ds != null && DataSourceID != "")
 129                                 ds.DataSourceChanged += new EventHandler (OnDataSourceChanged);
 130                 }
 131
 132                 protected override void OnPagePreLoad (object sender, EventArgs e)
 133                 {
 134                         base.OnPagePreLoad (sender, e);
 135
 136                         Initialize ();
 137                 }
 138
 139                 protected void InternalPerformDataBinding ()
 140                 {
 141                         HierarchicalDataBoundControlAdapter adapter
 142                                 = Adapter as HierarchicalDataBoundControlAdapter;
 143                         if (adapter != null)
 144                                 adapter.PerformDataBinding ();
 145                         else
 146                                 PerformDataBinding ();
 147                 }
 148
 149                 protected internal virtual void PerformDataBinding ()
 150                 {
 151                 }
 152
 153                 protected override void PerformSelect ()
 154                 {
 155                         OnDataBinding (EventArgs.Empty);
 156                         InternalPerformDataBinding ();
 157                         // The PerformDataBinding method has completed.
 158                         RequiresDataBinding = false;
 159                         MarkAsDataBound ();
 160                         OnDataBound (EventArgs.Empty);
 161                 }
 162
 163                 protected override void ValidateDataSource (object dataSource)
 164                 {
 165                         if (dataSource == null || dataSource is IHierarchicalDataSource || dataSource is IHierarchicalEnumerable)
 166                                 return;
 167                         throw new InvalidOperationException ("Invalid data source");
 168                 }
 169         }
 170 }
 171 #endif
 172
 173