Hi,
In this article I'll provide a simple trick in order to solve the missing ASP.NET Repeater Empty Data Template ...
By Default ASP.NET Repeater provides 4 Builtin Templates
- HeaderTemplate
- ItemTemplate
- AlternateItemTemplate
- FooterTemplate
We often need to show something when there is no data .... For example show "No Data" Message !
<EmptyTemplate>
<strong>No Data !</strong>
</EmptyTemplate>So there is the trick, Create a Custom Server Control inherited from System.Web.UI.WebControls.Repeater as the following
[ToolboxData("<{0}:CustomRepeater runat=server></{0}:CustomRepeater>")]
public class CustomRepeater : Repeater
{
[Category("Data")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
[PersistenceMode(PersistenceMode.InnerProperty)]
public ITemplate EmptyTemplate
{
get;
set;
}
protected override void OnDataBinding(EventArgs e)
{
base.OnDataBinding(e);
if (this.Items.Count <= 0 && EmptyTemplate != null)
{
EmptyTemplate.InstantiateIn(this);
}
}
}Now we got our EmptyTemplate but we can improve this a little bit more. I want to show HeaderTemplate and FooterTemplate even if there is no data.
So here is the modification to add to our Custom Repeater.
[ToolboxData("<{0}:CustomRepeater runat=server></{0}:CustomRepeater>")]
public class CustomRepeater : Repeater
{
[Category("Data")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
[PersistenceMode(PersistenceMode.InnerProperty)]
public ITemplate EmptyTemplate
{
get;
set;
}
protected override void OnDataBinding(EventArgs e)
{
base.OnDataBinding(e);
if (this.Items.Count <= 0 && EmptyTemplate != null)
{
HeaderTemplate.InstantiateIn(this);
EmptyTemplate.InstantiateIn(this);
FooterTemplate.InstantiateIn(this);
}
}
}
UPDATE 13/12/2008
After some tests, this solution seems to not works when working with PostBack.
HeaderTemplate, EmptyDataTemplate and FooterTemplate are not re-created on PostBack. So we need to Overrides CreateChildControls methods.
Here is the Updated Code :
[ToolboxData("<{0}:CustomRepeater runat=server></{0}:CustomRepeater>")]
public class CustomRepeater : Repeater
{
#region Public Properties
[Category("Data")]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
[PersistenceMode(PersistenceMode.InnerProperty)]
public ITemplate EmptyTemplate
{
get;
set;
}
#endregion
#region Protected Overrides Methods
protected override void CreateChildControls()
{
base.CreateChildControls();
HandleEmptyData();
}
protected override void OnDataBinding(EventArgs e)
{
base.OnDataBinding(e);
HandleEmptyData();
}
#endregion
#region Private Methods
private void HandleEmptyData()
{
if (this.Items.Count <= 0 && EmptyTemplate != null)
{
this.Controls.Clear();
HeaderTemplate.InstantiateIn(this);
EmptyTemplate.InstantiateIn(this);
FooterTemplate.InstantiateIn(this);
}
}
#endregion
}
Hope this help's!
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