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.DataBoundControlDesigner, " + Consts.AssemblySystem_Design, "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                 /* Used for controls that used to inherit from
  53                  * WebControl, so the tag can propagate upwards
  54                  */
  55                 internal DataBoundControl (HtmlTextWriterTag tag) : base (tag)
  56                 {
  57                 }
  58
  59
  60                 protected virtual IDataSource GetDataSource ()
  61                 {
  62                         if (IsBoundUsingDataSourceID) {
  63                                 Control ctrl = NamingContainer.FindControl (DataSourceID);
  64                                 if (ctrl == null)
  65                                         throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
  66                                 if (!(ctrl is IDataSource))
  67                                         throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IDataSource.", DataSourceID));
  68                                 return (IDataSource) ctrl;
  69                         }
  70
  71                         if (DataSource == null) return null;
  72
  73                         IDataSource ds = DataSource as IDataSource;
  74                         if (ds != null) return ds;
  75
  76                         IEnumerable ie = DataSourceHelper.GetResolvedDataSource (DataSource, DataMember);
  77                         if (ie != null) return new CollectionDataSource (ie);
  78
  79                         throw new HttpException (string.Format ("Unexpected data source type: {0}", DataSource.GetType()));
  80                 }
  81
  82                 protected virtual DataSourceView GetData ()
  83                 {
  84                         if (currentView == null)
  85                                 UpdateViewData ();
  86                         return currentView;
  87                 }
  88
  89                 DataSourceView InternalGetData ()
  90                 {
  91                         if (DataSource != null && IsBoundUsingDataSourceID)
  92                                 throw new HttpException ("Control bound using both DataSourceID and DataSource properties.");
  93
  94                         IDataSource ds = GetDataSource ();
  95                         if (ds != null)
  96                                 return ds.GetView (DataMember);
  97                         else
  98                                 return null;
  99                 }
 100
 101                 protected override void OnDataPropertyChanged ()
 102                 {
 103                         base.OnDataPropertyChanged ();
 104                         UpdateViewData ();
 105                 }
 106
 107                 protected virtual void OnDataSourceViewChanged (object sender, EventArgs e)
 108                 {
 109                         RequiresDataBinding = true;
 110                 }
 111
 112                 protected override void OnPagePreLoad (object sender, EventArgs e)
 113                 {
 114                         base.OnPagePreLoad (sender, e);
 115                         UpdateViewData ();
 116                 }
 117
 118                 void UpdateViewData ()
 119                 {
 120                         DataSourceView view = InternalGetData ();
 121                         if (view == currentView) return;
 122
 123                         if (currentView != null)
 124                                 currentView.DataSourceViewChanged -= new EventHandler (OnDataSourceViewChanged);
 125
 126                         currentView = view;
 127
 128                         if (view != null)
 129                                 view.DataSourceViewChanged += new EventHandler (OnDataSourceViewChanged);
 130                 }
 131
 132                 protected internal override void OnLoad (EventArgs e)
 133                 {
 134                         if (IsBoundUsingDataSourceID && (!Page.IsPostBack || !EnableViewState))
 135                                 RequiresDataBinding = true;
 136
 137                         base.OnLoad(e);
 138                 }
 139
 140                 protected internal virtual void PerformDataBinding (IEnumerable data)
 141                 {
 142                 }
 143
 144                 protected override void ValidateDataSource (object dataSource)
 145                 {
 146                         if (dataSource is IListSource || dataSource is IEnumerable || dataSource is IDataSource)
 147                                 return;
 148                         throw new ArgumentException ("Invalid data source source type. The data source must be of type IListSource, IEnumerable or IDataSource.");
 149                 }
 150
 151                 [ThemeableAttribute (false)]
 152                 [DefaultValueAttribute ("")]
 153                 [WebCategoryAttribute ("Data")]
 154                 public virtual string DataMember
 155                 {
 156                         get {
 157                                 object o = ViewState["DataMember"];
 158                                 if(o!=null)
 159                                         return (string)o;
 160                                 return String.Empty;
 161                         }
 162                         set {
 163                                 ViewState["DataMember"] = value;
 164                         }
 165                 }
 166
 167                 [IDReferencePropertyAttribute (typeof(DataSourceControl))]
 168                 public override string DataSourceID {
 169                         get {
 170                                 object o = ViewState ["DataSourceID"];
 171                                 if (o != null)
 172                                         return (string)o;
 173
 174                                 return String.Empty;
 175                         }
 176                         set {
 177                                 ViewState ["DataSourceID"] = value;
 178                                 base.DataSourceID = value;
 179                         }
 180                 }
 181
 182                 protected override void PerformSelect ()
 183                 {
 184                         OnDataBinding (EventArgs.Empty);
 185                         DataSourceView view = GetData ();
 186                         if (view != null)
 187                                 view.Select (SelectArguments, new DataSourceViewSelectCallback (OnSelect));
 188                 }
 189
 190                 void OnSelect (IEnumerable data)
 191                 {
 192                         PerformDataBinding (data);
 193                         OnDataBound (EventArgs.Empty);
 194                 }
 195
 196                 protected virtual DataSourceSelectArguments CreateDataSourceSelectArguments ()
 197                 {
 198                         return DataSourceSelectArguments.Empty;
 199                 }
 200
 201                 protected DataSourceSelectArguments SelectArguments {
 202                         get {
 203                                 if (selectArguments == null)
 204                                         selectArguments = CreateDataSourceSelectArguments ();
 205                                 return selectArguments;
 206                         }
 207                 }
 208
 209                 [MonoTODO]
 210                 protected void MarkAsDataBound ()
 211                 {
 212                         throw new NotImplementedException ();
 213                 }
 214         }
 215 }
 216 #endif
 217