HierarchicalDataBoundControl.cs :  » 2.6.4-mono-.net-core » System.Web » System » Web » UI » WebControls » C# / CSharp Open Source

//
// System.Web.UI.WebControls.HierarchicalDataBoundControl.cs
//
// Authors:
//  Lluis Sanchez Gual (lluis@novell.com)
//
// (C) 2004 Novell, Inc (http://www.novell.com)
//

//
// Permission is hereby granted, free of charge, to any person obtaining
// a copy of this software and associated documentation files (the
// "Software"), to deal in the Software without restriction, including
// without limitation the rights to use, copy, modify, merge, publish,
// distribute, sublicense, and/or sell copies of the Software, and to
// permit persons to whom the Software is furnished to do so, subject to
// the following conditions:
// 
// The above copyright notice and this permission notice shall be
// included in all copies or substantial portions of the Software.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
//

#if NET_2_0
using System.Collections;
using System.ComponentModel;
using System.Web.UI;
using System.Web.UI.WebControls.Adapters;

namespace System.Web.UI.WebControls{
  [DesignerAttribute ("System.Web.UI.Design.WebControls.HierarchicalDataBoundControlDesigner, " + Consts.AssemblySystem_Design, "System.ComponentModel.Design.IDesigner")]
  public abstract class HierarchicalDataBoundControl : BaseDataBoundControl
  {
    [IDReferencePropertyAttribute (typeof(HierarchicalDataSourceControl))]
    public override string DataSourceID {
      get {
        object o = ViewState ["DataSourceID"];
        if (o != null)
          return (string)o;
        
        return String.Empty;
      }
      set {
        if (Initialized)
          RequiresDataBinding = true;
        
        ViewState ["DataSourceID"] = value;
      }
    }
    
    protected virtual HierarchicalDataSourceView GetData (string viewPath)
    {
      if (DataSource != null && DataSourceID != "")
        throw new HttpException ();  
      IHierarchicalDataSource ds = GetDataSource ();
      if (ds != null)
        return ds.GetHierarchicalView (viewPath);
      
      if (DataSource is IHierarchicalEnumerable)
        return new ReadOnlyDataSourceView ((IHierarchicalEnumerable) DataSource);
      
      return null;
    }
    
    protected virtual IHierarchicalDataSource GetDataSource ()
    {
      if (IsBoundUsingDataSourceID) {
        Control ctrl = FindDataSource ();

        if (ctrl == null)
          throw new HttpException (string.Format ("A control with ID '{0}' could not be found.", DataSourceID));
        if (!(ctrl is IHierarchicalDataSource))
          throw new HttpException (string.Format ("The control with ID '{0}' is not a control of type IHierarchicalDataSource.", DataSourceID));
        return (IHierarchicalDataSource) ctrl;
      }
      
      return DataSource as IHierarchicalDataSource;
    }

    bool IsDataBound {
      get {
        return ViewState.GetBool ("DataBound", false);
      }
      set {
        ViewState ["DataBound"] = value;
      }
    }

    protected void MarkAsDataBound ()
    {
      IsDataBound = true;
    }
    
    protected override void OnDataPropertyChanged ()
    {
      RequiresDataBinding = true;
    }
    
    protected virtual void OnDataSourceChanged (object sender, EventArgs e)
    {
      RequiresDataBinding = true;
    }

    protected internal override void OnLoad (EventArgs e)
    {
      if (!Initialized) {
        Initialize ();
        ConfirmInitState ();
      }
      
      base.OnLoad(e);
    }

    void Initialize ()
    {
      if (!Page.IsPostBack || (IsViewStateEnabled && !IsDataBound))
        RequiresDataBinding = true;

      IHierarchicalDataSource ds = GetDataSource ();
      if (ds != null && DataSourceID != "")
        ds.DataSourceChanged += new EventHandler (OnDataSourceChanged);
    }

    protected override void OnPagePreLoad (object sender, EventArgs e)
    {
      base.OnPagePreLoad (sender, e);
      
      Initialize ();
    }
    
    protected void InternalPerformDataBinding ()
    {
      HierarchicalDataBoundControlAdapter adapter 
        = Adapter as HierarchicalDataBoundControlAdapter;
      if (adapter != null)
        adapter.PerformDataBinding ();
      else
        PerformDataBinding ();
    }
    
    protected internal virtual void PerformDataBinding ()
    {
    }
    
    protected override void PerformSelect ()
    {
      OnDataBinding (EventArgs.Empty);
      InternalPerformDataBinding ();
      // The PerformDataBinding method has completed.
      RequiresDataBinding = false;
      MarkAsDataBound ();
      OnDataBound (EventArgs.Empty);
    }
    
    protected override void ValidateDataSource (object dataSource)
    {
      if (dataSource == null || dataSource is IHierarchicalDataSource || dataSource is IHierarchicalEnumerable)
        return;
      throw new InvalidOperationException ("Invalid data source");
    }
  }
}
#endif