Action <EventStoreCatchUpSubscription, ResolvedEvent> EventAppeared(Projection projection)
=> (_, e) =>
{
// always double check if it is a system event ;)
if (e.OriginalEvent.EventType.StartsWith("$"))
{
return;
}
// get the configured clr type name for deserializing the event
if (!_typeMapper.TryGetType(e.Event.EventType, out var eventType))
{
Log.Debug("Failed to find clr type for {eventType}. Skipping...", e.Event.EventType);
}
else
{
// deserialize event
var domainEvent = _serializer.Deserialize(e.Event.Data, eventType);
// try to execute the projection
if (projection.CanHandle(domainEvent))
{
projection.Handle(domainEvent).GetAwaiter().GetResult();
Log.Debug("{projection} handled {event}", projection, domainEvent);
}
}
// store the current checkpoint
_checkpointStore.SetCheckpoint(e.OriginalPosition, projection).GetAwaiter().GetResult();
};
public async Task Project(object @event)
{
if (!_projection.CanHandle(@event.GetType()))
{
return;
}
await _projection.Handle(@event.GetType(), @event);
}