How to implement Singleton via Domain Components

Hi Igor,
We are working on your issue and will answer you as soon as possible. We are sorry for the delay.
Thanks,
Michael.

Hello Igor,
You cannot define logic for the static interface' property. You will need to implement an additional helper class to do this. This class should use the ObjectSpace to create or load the singleton object. The other implementation should be the same as in persistent classes.
Thanks,
Anatol

Hello,
may I have a simple example of this to make sure best way is used.
Thanks

Hi Igor,
I have created a project based on example How to Implement a Singleton class, which uses the DC technology. It is attached. The essential code follows:

C#
public sealed partial class SolutionModule : ModuleBase {  
    ...  
    public override void Setup(XafApplication application) {  
        if (!XafTypesInfo.IsInitialized) {  
            XafTypesInfo.Instance.RegisterEntity("Singleton", typeof(ISingleton));  
        }  
        base.Setup(application);  
    }  
}  

[DomainComponent]  
public interface ISingleton {  
    string Name { get; set; }  
    string Description { get; set; }  
}  

[DomainLogic(typeof(ISingleton))]  
public class SingletonLogic {  
    public static ISingleton GetInstance(IObjectSpace objectSpace) {  
        ISingleton result = objectSpace.FindObject<ISingleton>(null);  
        if (result == null) {  
            result = objectSpace.CreateObject<ISingleton>();  
            result.Name = "My Singleton";  
            result.Description = "Empty";  
        }  
        return result;  
    }  
    public static void OnDeleting(ISingleton instance) {  
        throw new Exception("Cannot be deleted");  
    }  
}  

public partial class ShowSingletonController : ViewController {  
    public ShowSingletonController() {  
        PopupWindowShowAction action = new PopupWindowShowAction(this, "ShowSingleton", DevExpress.Persistent.Base.PredefinedCategory.Unspecified);  
        action.CustomizePopupWindowParams += new CustomizePopupWindowParamsEventHandler(action_CustomizePopupWindowParams);  
    }  
    void action_CustomizePopupWindowParams(object sender, CustomizePopupWindowParamsEventArgs e) {  
        IObjectSpace objectSpace = Application.CreateObjectSpace();  
        e.View = Application.CreateDetailView(objectSpace, SingletonLogic.GetInstance(objectSpace));  
    }  
}  

Thanks,
Michael.