Where to subscribe to domain events

Question

Within my application service, I have the following code for publishing domain events:

var document = await dbContext.Documents.GetAggregateAsync(message.DocumentId);

publisher.SubscribeTo<DocumentOwnerChanged>()
    .UsingDelegate(
        async a => await messageGateway.DocumentOwnerChanged(1, 1, 1));

document.ChangeOwner(message.OwnerId);

await dbContext.SaveChangesAsync();

await publisher.Publish(document.ReleaseEvents());

I'm trying to decide if I like having this knowledge of publishing events within the app service or if I should externalize this somewhere up higher in the root.

thoughts?

Answer 1

You would typically register handlers in the Composition Root, unless you had to dynamically register and un-register handlers based on other messages.

There is some discussion around this here

You would publish domain events typically in your domain layer:

public void SomeDomainBehaviour()
{
    // do something domain-y
    DomainEvents.Publish(new DomainEvent());
}

Jimmy Bogard discusses other ways of publishing Domain Events here