public AsyncEvent <K> Observe <K>(Expression <Func <T, K> > property)
{
var prop = property.GetProperty();
if (_events.ContainsKey(prop))
{
return(_events[prop] as AsyncEvent <K>);
}
var val = (K)_state[prop];
var ae = new AsyncEvent <K>(val);
_events.Add(prop, ae);
return(ae);
}
public AsyncEvent <CollectionChanges <K> > Observe <K>(Expression <Func <T, IStateList <K> > > property)
{
var prop = property.GetProperty();
if (_events.ContainsKey(prop))
{
return(_events[prop] as AsyncEvent <CollectionChanges <K> >);
}
var val = (List <K>)_state[prop];
var ae = new AsyncEvent <CollectionChanges <K> >(Changes.Init(val))
.OnSubscribe(async cb => await cb.Invoke(Changes.Init((List <K>)_state[prop])));
_events.Add(prop, ae);
return(ae);
}
/// <summary>
/// Converts an AsyncEvent to IObservable of Unit (since there is not IObservable of void. Using the
/// owner to control the weak action lifespan and unsubscribe when observer is disposed
/// </summary>
/// <typeparam name="T"></typeparam>
/// <typeparam name="TOwner"></typeparam>
/// <param name="source"></param>
/// <param name="owner"></param>
/// <returns></returns>
public static IObservable <Unit> ToObservable <TOwner>(this AsyncEvent source, TOwner owner)
where TOwner : INotifyDisposable
{
return(Observable.Create <Unit>(async observer =>
{
Func <Task> handler = () =>
{
observer.OnNext(Unit.Default);
return Task.CompletedTask;
};
await source.Subscribe(owner, handler);
return Disposables.Call(() =>
{
source.Unsubscribe(owner, handler);
});
}));
}
public ServiceCollectionField(IEnumerable <T> values = null)
{
if (values != null)
{
_items = new List <T>(values);
}
else
{
_items = new List <T>();
}
Changed = new AsyncEvent <CollectionChanges <T> >(Changes.Init(_items))
// instead of returning the latest change, on subscribe, we return a reset to the entire list
.OnSubscribe(async cb =>
{
await cb.Invoke(Changes.Init(_items));
});
}
public ServiceField(T value)
{
_value = value;
Changed = new AsyncEvent <T>(_value);
}