Interface IIntegrationEventPublisher

Namespace: Trellis.Mediator

Assembly: Trellis.Mediator.dll

Publishes a single IIntegrationEvent, together with the stable message identity a transport must carry onto the wire, to its consumers. The transactional outbox relay resolves this contract to deliver integration events durably after the producing transaction commits.

public interface IIntegrationEventPublisher

Extension Methods: MaybeExtensions.AsMaybe<T>(T)

AggregateTestMutator.ClearMaybeField<TEntity, TValue>(TEntity, Expression<Func<TEntity, Maybe<TValue>>>)

AggregateTestMutator.SetMaybeField<TEntity, TValue>(TEntity, Expression<Func<TEntity, Maybe<TValue>>>, TValue?)

Remarks

The default implementation fans out to in-process IIntegrationEventHandler<TEvent> registrations for the event's runtime type - the right choice for a modular monolith and for tests. To deliver to other services, replace this registration with a message-broker adapter (for example Azure Service Bus or Kafka); the producing side - aggregates, translators, and the outbox - does not change. This is the seam that keeps the outbox transport-agnostic.

The message identity is part of the contract, not an optional extra. The single method takes an OutboundIntegrationMessage rather than a bare event so a transport cannot publish without the id: relay delivery is at-least-once, and stamping MessageId verbatim onto the wire is what lets consumer-side (ConsumerId, MessageId) deduplication recognize a redelivery. An adapter that minted its own id per attempt would make every redelivery look like a new message and silently defeat the inbox. In-process implementations may simply ignore the id - there is no wire and nothing to deduplicate.

Implementations are expected to be best-effort: non-cancellation handler exceptions are logged and swallowed so one consumer's failure does not block the others. OperationCanceledException matching the supplied token is the one exception that propagates so the relay can abort cleanly.

Methods

PublishAsync(OutboundIntegrationMessage, CancellationToken)

Publishes the specified message to all matching consumers.

ValueTask PublishAsync(OutboundIntegrationMessage message, CancellationToken cancellationToken)

Parameters

message OutboundIntegrationMessage: The message to publish, carrying the event and its stable id. Handler resolution uses message.Event.GetType().
cancellationToken CancellationToken: A token to observe while waiting on the consumers.

Returns