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