Clarification for reading multiple events about watermill

[roblaszczak]

My guess is you'd have to have a composite of struct each listening for a single event type.

Correct. In this situation, I will suggest to not put any logic to Handle() but just call another service which will be the same for both.

[Dionid]

@delaneyj Have you find a way that satisfied your request?
@roblaszczak Can you write example, please?

[roblaszczak]

example:

type readModelBuilder interface {
	buildBookingsReadModel(guestName string) error
}

type BookingsFinancialReport struct {
	readModelBuilder readModelBuilder
}

func (b BookingsFinancialReport) HandlerName() string {
	// this name is passed to EventsSubscriberConstructor and used to generate queue name
	return "BookingsFinancialReport"
}

func (BookingsFinancialReport) NewEvent() interface{} {
	return &RoomBooked{}
}

func (b *BookingsFinancialReport) Handle(ctx context.Context, e interface{}) error {
	event := e.(*RoomBooked)

	return b.readModelBuilder.buildBookingsReadModel(event.GuestName)
}

type SpecialBookingsFinancialReport struct {
	readModelBuilder readModelBuilder
}

func (b SpecialBookingsFinancialReport) HandlerName() string {
	return "SpecialBookingsFinancialReport"
}

func (SpecialBookingsFinancialReport) NewEvent() interface{} {
	return &SpecialRoomBooked{}
}

func (b *SpecialBookingsFinancialReport) Handle(ctx context.Context, e interface{}) error {
	event := e.(*SpecialRoomBooked)

	return b.readModelBuilder.buildBookingsReadModel(event.VIPGuestName)
}

In that case, EventHandler is just calling something which is responsible for building read models (also, Single Responsibility Principle will be satisfied here :)).

did it help? :)

[roblaszczak]

I hope this is clean. If not - please let us know :)