Templated RadDock control inside of a RadDockZone?

Question

I've created a templated ASP.NET user control based on the RadDock control. However, when adding such a control to a RadDockZone causes a runtime error stating that it can only contain RadDock controls. Is there any way to solve this?

Templated user control markup

<%@ Control Language="C#" AutoEventWireup="true" CodeBehind="TemplatedDock.ascx.cs" Inherits="TemplatedDock" %>
<telerik:RadDock ID="RadDock1" runat="server" EnableAnimation="True" DockHandle="Grip"     Resizable="True">
    <ContentTemplate>
        <asp:PlaceHolder ID="dockPlaceholder" runat="server"></asp:PlaceHolder>
    </ContentTemplate>
</telerik:RadDock>

Templated user control code-behind

public partial class TemplatedDock : System.Web.UI.UserControl
{
    private ITemplate _content;

    [TemplateContainer(typeof(ContentContainer))]
    [PersistenceMode(PersistenceMode.InnerProperty)]
    [TemplateInstance(TemplateInstance.Single)]
    public ITemplate Content
    {
        get
        {
            return _content;
        }
        set
        {
            _content = value;
        }
    }
    void Page_Init()
    {
        if (_content != null)
        {
            ContentContainer container = new ContentContainer();
            _content.InstantiateIn(container);
            dockPlaceholder.Controls.Add(container);
        }
    }
}
public class ContentContainer : Control, INamingContainer{}

}

Usage in RadDockZone

<telerik:RadDockZone ID="RadDockZone1" runat="server">
    <a:TemplatedDock>
        <Content>
             <telerik:RadGrid ID="someGrid" runat="server"></telerik:RadGrid>
        </Content>
    </a:TemplatedDock>
</telerik:RadDockZone>

Answer 1

There is no way for this to happen. A RadDockZone must have only RadDock controls as children. Custom controls have a different type and will, therefore throw an exception. The zone is tightly coupled with the dock to offer easy integration like drag-drop, state saving, etc., and this has its price.