//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)
=> (_, e) =>
{
// check system events and ignore them...
if (e.OriginalEvent.EventType.StartsWith("$"))
{
return;
}
// find event type
var eventType = EventTypeMapper.GetType(e.Event.EventType);
if (eventType == null)
{
return;
}
// deserialize the event.
var domainEvent = e.Deserialze();
//build your projection
projection.Handle(domainEvent);
//store current checkpoint
checkpointStore.SetCheckpoint(e.OriginalPosition.Value, projection);
Console.WriteLine($"{DateTime.UtcNow.Ticks}---{e.Event.EventStreamId}-{domainEvent} projected into {projection}-{e.OriginalPosition.Value}");
};
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);
}
public async Task <long> SaveSnapshotAsync <T>(Snapshot snapshot) where T : Aggregate
{
var stream = GetStreamName <T>(snapshot.AggregateId);
var snapshotEvent = new EventData(
snapshot.Id,
EventTypeMapper.GetTypeName(snapshot.GetType()),
EventSerializer.IsJsonSerializer,
EventSerializer.Serialize(snapshot),
null);
var result = await eventStoreConnection.AppendToStreamAsync(stream, ExpectedVersion.Any, snapshotEvent);
return(result.LogPosition.CommitPosition);
}
