public static IObjectFieldDescriptor Subscribe <T>(
this IObjectFieldDescriptor descriptor,
Func <IResolverContext, Task <IAsyncEnumerable <T> > > subscribe)
{
return(descriptor.Subscribe(async ctx =>
{
IAsyncEnumerable <T> enumerable = await subscribe(ctx).ConfigureAwait(false);
return new SourceStreamWrapper(new AsyncEnumerableStreamAdapter <T>(enumerable));
}));
}
public static IObjectFieldDescriptor Subscribe <T>(
this IObjectFieldDescriptor descriptor,
Func <IResolverContext, Task <IObservable <T> > > subscribe)
{
return(descriptor.Subscribe(async ctx =>
{
IObservable <T> observable = await subscribe(ctx).ConfigureAwait(false);
return new ObservableSourceStreamAdapter <T>(observable);
}));
}
/// <summary>
/// Subscribes to a topic that is resolved by executing <paramref name="resolveTopic" />.
/// </summary>
/// <param name="descriptor">
/// The object field descriptor.
/// </param>
/// <param name="resolveTopic">
/// A delegate that resolves a value that will used as topic.
/// </param>
/// <typeparam name="TMessage">
/// The type of the message / event payload.
/// </typeparam>
public static IObjectFieldDescriptor SubscribeToTopic <TTopic, TMessage>(
this IObjectFieldDescriptor descriptor,
Func <IResolverContext, ValueTask <TTopic> > resolveTopic)
{
return(descriptor.Subscribe(async ctx =>
{
ITopicEventReceiver receiver = ctx.Service <ITopicEventReceiver>();
TTopic topic = await resolveTopic(ctx).ConfigureAwait(false);
return await receiver.SubscribeAsync <TTopic, TMessage>(topic).ConfigureAwait(false);
}));
}
public static IObjectFieldDescriptor Subscribe <T>(
this IObjectFieldDescriptor descriptor,
Func <IResolverContext, IAsyncEnumerable <T> > subscribe) =>
descriptor.Subscribe(ctx => Task.FromResult(subscribe(ctx)));