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

   1 //
   2 // System.Web.UI.WebControls.DataBoundControl
   3 //
   4 // Authors:
   5 //      Ben Maurer (bmaurer@users.sourceforge.net)
   6 //      Sanjay Gupta (gsanjay@novell.com)
   7 //
   8 // (C) 2003 Ben Maurer
   9 // (C) 2004 Novell, Inc. (http://www.novell.com)
  10 //
  11
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining
  14 // a copy of this software and associated documentation files (the
  15 // "Software"), to deal in the Software without restriction, including
  16 // without limitation the rights to use, copy, modify, merge, publish,
  17 // distribute, sublicense, and/or sell copies of the Software, and to
  18 // permit persons to whom the Software is furnished to do so, subject to
  19 // the following conditions:
  20 //
  21 // The above copyright notice and this permission notice shall be
  22 // included in all copies or substantial portions of the Software.
  23 //
  24 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  25 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  26 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  27 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  28 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  29 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  30 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  31 //
  32
  33 #if NET_2_0
  34 using System.Collections;
  35 using System.Collections.Specialized;
  36 using System.Text;
  37 using System.Web.Util;
  38 using System.ComponentModel;
  39
  40 namespace System.Web.UI.WebControls {
  41
  42         [DesignerAttribute ("System.Web.UI.Design.WebControls.HierarchicalDataBoundControlDesigner, System.Design, Version=2.0.3600.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", "System.ComponentModel.Design.IDesigner")]
  43         public abstract class DataBoundControl : BaseDataBoundControl
  44         {
  45                 DataSourceSelectArguments selectArguments;
  46                 DataSourceView currentView;
  47
  48                 protected DataBoundControl ()
  49                 {
  50                 }
  51
  52                 protected IDataSource GetDataSource ()
  53                 {
  54                         if (IsBoundUsingDataSourceID) {
  55                                 Control ctrl = NamingContainer.FindControl (DataSourceID);
  56                                 if (ctrl == null)
  57                                         throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
  58                                 if (!(ctrl is IDataSource))
  59                                         throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IDataSource.", DataSourceID));
  60                                 return (IDataSource) ctrl;
  61                         }
  62
  63                         if (DataSource == null) return null;
  64
  65                         IDataSource ds = DataSource as IDataSource;
  66                         if (ds != null) return ds;
  67
  68                         IEnumerable ie = DataSourceHelper.GetResolvedDataSource (DataSource, DataMember);
  69                         if (ie != null) return new CollectionDataSource (ie);
  70
  71                         throw new HttpException (string.Format ("Unexpected data source type: {0}", DataSource.GetType()));
  72                 }
  73
  74                 protected DataSourceView GetData ()
  75                 {
  76                         if (currentView == null)
  77                                 UpdateViewData ();
  78                         return currentView;
  79                 }
  80
  81                 DataSourceView InternalGetData ()
  82                 {
  83                         if (DataSource != null && IsBoundUsingDataSourceID)
  84                                 throw new HttpException ("Control bound using both DataSourceID and DataSource properties.");
  85
  86                         IDataSource ds = GetDataSource ();
  87                         if (ds != null)
  88                                 return ds.GetView (DataMember);
  89                         else
  90                                 return null;
  91                 }
  92
  93                 protected override void OnDataPropertyChanged ()
  94                 {
  95                         base.OnDataPropertyChanged ();
  96                         UpdateViewData ();
  97                 }
  98
  99                 protected virtual void OnDataSourceViewChanged (object sender, EventArgs e)
 100                 {
 101                         RequiresDataBinding = true;
 102                 }
 103
 104                 protected override void OnPagePreLoad (object sender, EventArgs e)
 105                 {
 106                         base.OnPagePreLoad (sender, e);
 107                         UpdateViewData ();
 108                 }
 109
 110                 void UpdateViewData ()
 111                 {
 112                         DataSourceView view = InternalGetData ();
 113                         if (view == currentView) return;
 114
 115                         if (currentView != null)
 116                                 currentView.DataSourceViewChanged -= new EventHandler (OnDataSourceViewChanged);
 117
 118                         currentView = view;
 119
 120                         if (view != null)
 121                                 view.DataSourceViewChanged += new EventHandler (OnDataSourceViewChanged);
 122                 }
 123
 124                 // should be `internal protected' (why, oh WHY did they do that !?!)
 125                 protected override void OnLoad (EventArgs e)
 126                 {
 127                         if (IsBoundUsingDataSourceID && (!Page.IsPostBack || !EnableViewState))
 128                                 RequiresDataBinding = true;
 129
 130                         base.OnLoad(e);
 131                 }
 132
 133                 protected virtual void PerformDataBinding (IEnumerable data)
 134                 {
 135                         OnDataBinding (EventArgs.Empty);
 136                 }
 137
 138                 protected override void ValidateDataSource (object dataSource)
 139                 {
 140                         if (dataSource is IListSource || dataSource is IEnumerable || dataSource is IDataSource)
 141                                 return;
 142                         throw new ArgumentException ("Invalid data source source type. The data source must be of type IListSource, IEnumerable or IDataSource.");
 143                 }
 144
 145                 [ThemeableAttribute (false)]
 146                 [DefaultValueAttribute ("")]
 147                 [WebCategoryAttribute ("Data")]
 148                 public string DataMember
 149                 {
 150                         get {
 151                                 object o = ViewState["DataMember"];
 152                                 if(o!=null)
 153                                         return (string)o;
 154                                 return String.Empty;
 155                         }
 156                         set {
 157                                 ViewState["DataMember"] = value;
 158                         }
 159                 }
 160
 161             [IDReferencePropertyAttribute (typeof(HierarchicalDataSourceControl))]
 162                 public override string DataSourceID {
 163                         get {
 164                                 object o = ViewState ["DataSourceID"];
 165                                 if (o != null)
 166                                         return (string)o;
 167
 168                                 return String.Empty;
 169                         }
 170                         set {
 171                                 ViewState ["DataSourceID"] = value;
 172                                 base.DataSourceID = value;
 173                         }
 174                 }
 175
 176                 protected override void PerformSelect ()
 177                 {
 178                         DataSourceView view = GetData ();
 179                         if (view != null)
 180                                 view.Select (SelectArguments, new DataSourceViewSelectCallback (OnSelect));
 181                 }
 182
 183                 void OnSelect (IEnumerable data)
 184                 {
 185                         PerformDataBinding (data);
 186                 }
 187
 188                 protected virtual DataSourceSelectArguments CreateDataSourceSelectArguments ()
 189                 {
 190                         return DataSourceSelectArguments.Empty;
 191                 }
 192
 193                 protected DataSourceSelectArguments SelectArguments {
 194                         get {
 195                                 if (selectArguments == null)
 196                                         selectArguments = CreateDataSourceSelectArguments ();
 197                                 return selectArguments;
 198                         }
 199                 }
 200         }
 201 }
 202 #endif
 203