createMessagingHandler(app: IApplication,options?: MessagingHandlerOptions): MessagingHandler
Builds the handler an application exports as queue to consume messages.
The broker is resolved from the application's registry rather than passed in,
so the subscriptions registered through IMessageBroker.subscribe anywhere
in the application are the ones this handler delivers into — there is only
ever one instance.
Resolution is lazy: the token is read on each invocation, not when this
factory runs, so the export can be built before app.start() has registered
anything.
options: MessagingHandlerOptions
Which named broker instance to dispatch into
The handler to assign to the Worker's queue export
At invocation time, when the resolved
token holds an IMessageBroker that is not a WorkersBroker — an
in-memory or Redis broker has no batch to dispatch and would silently drop
the delivery