private IDisposable DeepSubscribeInternal(string path, Action handler, Lifetime rootLifetime = null)
{
rootLifetime = rootLifetime ?? new Lifetime();
var observableRoot = DeepObservableRoot ?? this;
IObservableObject currentObservable = observableRoot;
var pathExpression = ObjectPathExpression.Parse(path);
List <IObjectPathElement> currentPath = new List <IObjectPathElement>();
var anyChangeLifetime = new Lifetime();
for (int i = 0; i < pathExpression.Elements.Count; i++)
{
var propertyElement = pathExpression.Elements[i] as PropertyPathElement;
if (propertyElement == null)
{
throw new NotSupportedException("Indexers are not supported for deep observability");
}
currentPath.Add(propertyElement);
ObjectPathExpression.TraceNode eval;
if (i == pathExpression.Elements.Count - 1 && propertyElement.PropertyName == ObservableObject.AnyProperty)
{
eval = new ObjectPathExpression.TraceNode()
{
Value = null
};
}
else
{
eval = new ObjectPathExpression(currentPath).EvaluateAndTraceInfo(observableRoot).Last();
if (i != pathExpression.Elements.Count - 1 && (eval.MemberInfo as PropertyInfo).PropertyType.GetInterfaces().Contains(typeof(IObservableObject)) == false)
{
throw new NotSupportedException($"element {eval.MemberInfo.Name} is not observable");
}
}
currentObservable.SubscribeForLifetime(propertyElement.PropertyName, () =>
{
handler();
if (anyChangeLifetime.IsExpired == false)
{
anyChangeLifetime.Dispose();
}
if (rootLifetime.IsExpired == false)
{
DeepSubscribeInternal(path, handler, rootLifetime);
}
}, EarliestOf(anyChangeLifetime, rootLifetime));
currentObservable = eval.Value as IObservableObject;
if (currentObservable == null)
{
break;
}
}
return(rootLifetime);
}
