Alert

public class ViewModel : DotvvmViewModelBase
{
    public bool Dismissed { get; set; } = false;

    public string Text { get; set; }

    public void AlertDismissed()
    {
        Text = "The alert was dismissed.";
    }

    public void Dismiss()
    {
        Dismissed = !Dismissed;
    }
}

public class ViewModel : MyViewModelBase
{
    
    public void DoSomething()
    {
        ExecuteWithAlert(() =>
        {
            // the action
        });
    }
}

public class MyViewModelBase : DotvvmViewModelBase
{

    [Bind(Direction.ServerToClient)]
    public string AlertText { get; set; }

    [Bind(Direction.ServerToClient)]
    public AlertType AlertType { get; set; }


    /// <summary>
    /// Executes the specified action and sets the appropriate alert messages.
    /// </summary>
    protected void ExecuteWithAlert(Action actionToExecute, 
        string successText = "The operation was successful.", 
        string errorText = "Sorry, an unexpected error has occurred.")
    {
        try
        {
            // execute the action
            actionToExecute();

            AlertText = successText;
            AlertType = AlertType.Success;
        }
        catch (DotVVM.Framework.Hosting.DotvvmInterruptRequestExecutionException)
        {
            // this exception is used for redirecting - don't catch it
            throw;
        }
        catch (Exception)
        {
            AlertText = errorText;
            AlertType = AlertType.Danger;
        }
    }

}