//https://eventstore.org/blog/20130306/getting-started-part-3-subscriptions/
//SubscribeToAllFrom(this IEventStoreConnection target,
// Position? lastCheckpoint,
// CatchUpSubscriptionSettings settings,
// Action<EventStoreCatchUpSubscription, ResolvedEvent> eventAppeared,
// Action<EventStoreCatchUpSubscription> liveProcessingStarted = null,
// Action<EventStoreCatchUpSubscription, SubscriptionDropReason, Exception> subscriptionDropped = null,
// UserCredentials userCredentials = null)
private Action <EventStoreCatchUpSubscription, ResolvedEvent> eventAppeared(Projection projection)
=> async(_, e) =>
{
// check system events and ignore them...
if (e.OriginalEvent.EventType.StartsWith("$"))
{
return;
}
// find event type
var eventType = EventTypeMapper.GetType(e.Event.EventType);
if (eventType == null)
{
return;
}
// deserialize the event.
var domainEvent = e.Deserialze();
//build your projection
await projection.Handle(domainEvent);
//store current checkpoint
await checkpointStore.SetCheckpoint(e.OriginalPosition.Value, projection);
Console.WriteLine($"{domainEvent} projected into {projection}");
};
public static object Deserialze(this ResolvedEvent resolvedEvent)
{
var dataType = EventTypeMapper.GetType(resolvedEvent.Event.EventType);
var jsonData = Encoding.UTF8.GetString(resolvedEvent.Event.Data);
var data = JsonConvert.DeserializeObject(jsonData, dataType);
return(data);
}