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.WebControls.Adapters;
  35
  36 namespace System.Web.UI.WebControls
  37 {
  38         [DesignerAttribute ("System.Web.UI.Design.WebControls.HierarchicalDataBoundControlDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
  39         public abstract class HierarchicalDataBoundControl : BaseDataBoundControl
  40         {
  41                 [IDReferencePropertyAttribute (typeof(HierarchicalDataSourceControl))]
  42                 public override string DataSourceID {
  43                         get {
  44                                 object o = ViewState ["DataSourceID"];
  45                                 if (o != null)
  46                                         return (string)o;
  47
  48                                 return String.Empty;
  49                         }
  50                         set {
  51                                 if (Initialized)
  52                                         RequiresDataBinding = true;
  53
  54                                 ViewState ["DataSourceID"] = value;
  55                         }
  56                 }
  57
  58                 protected virtual HierarchicalDataSourceView GetData (string viewPath)
  59                 {
  60                         if (DataSource != null && DataSourceID != "")
  61                                 throw new HttpException ();
  62
  63                         IHierarchicalDataSource ds = GetDataSource ();
  64                         if (ds != null)
  65                                 return ds.GetHierarchicalView (viewPath);
  66                         else
  67                                 return null;
  68                 }
  69
  70                 protected virtual IHierarchicalDataSource GetDataSource ()
  71                 {
  72                         if (IsBoundUsingDataSourceID) {
  73
  74                                 Control ctrl = FindDataSource ();
  75
  76                                 if (ctrl == null)
  77                                         throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
  78                                 if (!(ctrl is IHierarchicalDataSource))
  79                                         throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IHierarchicalDataSource.", DataSourceID));
  80                                 return (IHierarchicalDataSource) ctrl;
  81                         }
  82
  83                         return DataSource as IHierarchicalDataSource;
  84                 }
  85
  86                 bool IsDataBound {
  87                         get {
  88                                 return ViewState.GetBool ("DataBound", false);
  89                         }
  90                         set {
  91                                 ViewState ["DataBound"] = value;
  92                         }
  93                 }
  94
  95                 protected void MarkAsDataBound ()
  96                 {
  97                         IsDataBound = true;
  98                 }
  99
 100                 protected override void OnDataPropertyChanged ()
 101                 {
 102                         RequiresDataBinding = true;
 103                 }
 104
 105                 protected virtual void OnDataSourceChanged (object sender, EventArgs e)
 106                 {
 107                         RequiresDataBinding = true;
 108                 }
 109
 110                 protected internal override void OnLoad (EventArgs e)
 111                 {
 112                         if (!Initialized) {
 113                                 Initialize ();
 114                                 ConfirmInitState ();
 115                         }
 116
 117                         base.OnLoad(e);
 118                 }
 119
 120                 private void Initialize ()
 121                 {
 122                         if (!Page.IsPostBack || (IsViewStateEnabled && !IsDataBound))
 123                                 RequiresDataBinding = true;
 124
 125                         IHierarchicalDataSource ds = GetDataSource ();
 126                         if (ds != null && DataSourceID != "")
 127                                 ds.DataSourceChanged += new EventHandler (OnDataSourceChanged);
 128                 }
 129
 130                 protected override void OnPagePreLoad (object sender, EventArgs e)
 131                 {
 132                         base.OnPagePreLoad (sender, e);
 133
 134                         Initialize ();
 135                 }
 136
 137                 protected void InternalPerformDataBinding ()
 138                 {
 139                         HierarchicalDataBoundControlAdapter adapter
 140                                 = (HierarchicalDataBoundControlAdapter)Adapter;
 141                         if (adapter != null)
 142                                 adapter.PerformDataBinding ();
 143                         else
 144                                 PerformDataBinding ();
 145                 }
 146
 147                 protected internal virtual void PerformDataBinding ()
 148                 {
 149                 }
 150
 151                 protected override void PerformSelect ()
 152                 {
 153                         OnDataBinding (EventArgs.Empty);
 154                         InternalPerformDataBinding ();
 155                         // The PerformDataBinding method has completed.
 156                         RequiresDataBinding = false;
 157                         MarkAsDataBound ();
 158                         OnDataBound (EventArgs.Empty);
 159                 }
 160
 161                 protected override void ValidateDataSource (object dataSource)
 162                 {
 163                         if (dataSource == null || dataSource is IHierarchicalDataSource || dataSource is IHierarchicalEnumerable)
 164                                 return;
 165                         throw new InvalidOperationException ("Invalid data source");
 166                 }
 167         }
 168 }
 169 #endif
 170
 171