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) 2004-2010 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 using System.Collections;
  32 using System.ComponentModel;
  33 using System.Web.UI;
  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 && !String.IsNullOrEmpty (DataSourceID))
  61                                 throw new HttpException ();
  62                         IHierarchicalDataSource ds = GetDataSource ();
  63                         if (ds != null)
  64                                 return ds.GetHierarchicalView (viewPath);
  65
  66                         if (DataSource is IHierarchicalEnumerable)
  67                                 return new ReadOnlyDataSourceView ((IHierarchicalEnumerable) DataSource);
  68
  69                         return null;
  70                 }
  71
  72                 protected virtual IHierarchicalDataSource GetDataSource ()
  73                 {
  74                         if (IsBoundUsingDataSourceID) {
  75                                 Control ctrl = FindDataSource ();
  76
  77                                 if (ctrl == null)
  78                                         throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
  79                                 if (!(ctrl is IHierarchicalDataSource))
  80                                         throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IHierarchicalDataSource.", DataSourceID));
  81                                 return (IHierarchicalDataSource) ctrl;
  82                         }
  83
  84                         return DataSource as IHierarchicalDataSource;
  85                 }
  86
  87                 bool IsDataBound {
  88                         get { return ViewState.GetBool ("DataBound", false); }
  89                         set { ViewState ["DataBound"] = value; }
  90                 }
  91
  92                 protected void MarkAsDataBound ()
  93                 {
  94                         IsDataBound = true;
  95                 }
  96
  97                 protected override void OnDataPropertyChanged ()
  98                 {
  99                         RequiresDataBinding = true;
 100                 }
 101
 102                 protected virtual void OnDataSourceChanged (object sender, EventArgs e)
 103                 {
 104                         RequiresDataBinding = true;
 105                 }
 106
 107                 protected internal override void OnLoad (EventArgs e)
 108                 {
 109                         if (!Initialized) {
 110                                 Initialize ();
 111                                 ConfirmInitState ();
 112                         }
 113
 114                         base.OnLoad(e);
 115                 }
 116
 117                 void Initialize ()
 118                 {
 119                         if (!Page.IsPostBack || (IsViewStateEnabled && !IsDataBound))
 120                                 RequiresDataBinding = true;
 121
 122                         IHierarchicalDataSource ds = GetDataSource ();
 123                         if (ds != null && DataSourceID != "")
 124                                 ds.DataSourceChanged += new EventHandler (OnDataSourceChanged);
 125                 }
 126
 127                 protected override void OnPagePreLoad (object sender, EventArgs e)
 128                 {
 129                         base.OnPagePreLoad (sender, e);
 130
 131                         Initialize ();
 132                 }
 133
 134                 protected void InternalPerformDataBinding ()
 135                 {
 136                         HierarchicalDataBoundControlAdapter adapter
 137                                 = Adapter as HierarchicalDataBoundControlAdapter;
 138                         if (adapter != null)
 139                                 adapter.PerformDataBinding ();
 140                         else
 141                                 PerformDataBinding ();
 142                 }
 143
 144                 protected internal virtual void PerformDataBinding ()
 145                 {
 146                 }
 147
 148                 protected override void PerformSelect ()
 149                 {
 150                         OnDataBinding (EventArgs.Empty);
 151                         InternalPerformDataBinding ();
 152                         // The PerformDataBinding method has completed.
 153                         RequiresDataBinding = false;
 154                         MarkAsDataBound ();
 155                         OnDataBound (EventArgs.Empty);
 156                 }
 157
 158                 protected override void ValidateDataSource (object dataSource)
 159                 {
 160                         if (dataSource == null || dataSource is IHierarchicalDataSource || dataSource is IHierarchicalEnumerable)
 161                                 return;
 162                         throw new InvalidOperationException ("Invalid data source");
 163                 }
 164         }
 165 }
 166
 167
 168