/// <summary>
/// Creates a disposable subscription to the lifecycle.
/// </summary>
/// <param name="observable">The lifecycle observable.</param>
/// <param name="observerName">The name of the observer.</param>
/// <param name="stage">The stage to participate in.</param>
/// <param name="onStart">The delegate called when starting the specified lifecycle stage.</param>
/// <param name="onStop">Teh delegate to be called when stopping the specified lifecycle stage.</param>
/// <returns>A <see cref="IDisposable"/> instance which can be disposed to unsubscribe the observer from the lifecycle.</returns>
public static IDisposable Subscribe(this ILifecycleObservable observable, string observerName, int stage, Func <CancellationToken, Task> onStart, Func <CancellationToken, Task> onStop)
{
if (observable is null)
{
throw new ArgumentNullException(nameof(observable));
}
if (onStart is null)
{
throw new ArgumentNullException(nameof(onStart));
}
if (onStop is null)
{
return(StartupObserver.Create(observable, observerName, stage, onStart));
}
return(observable.Subscribe(observerName, stage, new Observer(onStart, onStop)));
}
public static IDisposable Create(ILifecycleObservable observable, string observerName, int stage, Func <CancellationToken, Task> onStart)
{
var observer = new StartupObserver(observable, observerName, stage, onStart);
return(observer._registration);
}
