func main() {
eventBus := eventhorizon.NewInternalEventBus()
commandBus := eventhorizon.NewInternalCommandBus()
addr := "localhost"
db := "demo"
newEventStore := func() (eventhorizon.EventStore, error) {
return eventhorizon.NewMongoEventStore(eventBus, addr, db)
}
newReadRepository := func(name string) (eventhorizon.ReadRepository, error) {
return eventhorizon.NewMongoReadRepository(addr, db, name)
}
common.Run(eventBus, commandBus, newEventStore, newReadRepository)
}
func main() {
// Create the event bus that distributes events.
eventBus := eventhorizon.NewInternalEventBus()
eventBus.AddGlobalHandler(&LoggerSubscriber{})
// Create the event store.
eventStore, err := eventhorizon.NewMongoEventStore(eventBus, "localhost", "demo")
if err != nil {
log.Fatalf("could not create event store: %s", err)
}
eventStore.RegisterEventType(&InviteCreated{}, func() eventhorizon.Event { return &InviteCreated{} })
eventStore.RegisterEventType(&InviteAccepted{}, func() eventhorizon.Event { return &InviteAccepted{} })
eventStore.RegisterEventType(&InviteDeclined{}, func() eventhorizon.Event { return &InviteDeclined{} })
// Create the aggregate repository.
repository, err := eventhorizon.NewCallbackRepository(eventStore)
if err != nil {
log.Fatalf("could not create repository: %s", err)
}
// Register an aggregate factory.
repository.RegisterAggregate(&InvitationAggregate{},
func(id eventhorizon.UUID) eventhorizon.Aggregate {
return &InvitationAggregate{
AggregateBase: eventhorizon.NewAggregateBase(id),
}
},
)
// Create the aggregate command handler.
handler, err := eventhorizon.NewAggregateCommandHandler(repository)
if err != nil {
log.Fatalf("could not create command handler: %s", err)
}
// Register the domain aggregates with the dispather. Remember to check for
// errors here in a real app!
handler.SetAggregate(&InvitationAggregate{}, &CreateInvite{})
handler.SetAggregate(&InvitationAggregate{}, &AcceptInvite{})
handler.SetAggregate(&InvitationAggregate{}, &DeclineInvite{})
// Create the command bus and register the handler for the commands.
commandBus := eventhorizon.NewInternalCommandBus()
commandBus.SetHandler(handler, &CreateInvite{})
commandBus.SetHandler(handler, &AcceptInvite{})
commandBus.SetHandler(handler, &DeclineInvite{})
// Create and register a read model for individual invitations.
invitationRepository, err := eventhorizon.NewMongoReadRepository("localhost", "demo", "invitations")
if err != nil {
log.Fatalf("could not create invitation repository: %s", err)
}
invitationRepository.SetModel(func() interface{} { return &Invitation{} })
invitationProjector := NewInvitationProjector(invitationRepository)
eventBus.AddHandler(invitationProjector, &InviteCreated{})
eventBus.AddHandler(invitationProjector, &InviteAccepted{})
eventBus.AddHandler(invitationProjector, &InviteDeclined{})
// Create and register a read model for a guest list.
eventID := eventhorizon.NewUUID()
guestListRepository, err := eventhorizon.NewMongoReadRepository("localhost", "demo", "guest_lists")
if err != nil {
log.Fatalf("could not create guest list repository: %s", err)
}
guestListRepository.SetModel(func() interface{} { return &GuestList{} })
guestListProjector := NewGuestListProjector(guestListRepository, eventID)
eventBus.AddHandler(guestListProjector, &InviteCreated{})
eventBus.AddHandler(guestListProjector, &InviteAccepted{})
eventBus.AddHandler(guestListProjector, &InviteDeclined{})
// Clear DB collections.
eventStore.Clear()
invitationRepository.Clear()
guestListRepository.Clear()
// Issue some invitations and responses.
// Note that Athena tries to decline the event, but that is not allowed
// by the domain logic in InvitationAggregate. The result is that she is
// still accepted.
athenaID := eventhorizon.NewUUID()
commandBus.HandleCommand(&CreateInvite{InvitationID: athenaID, Name: "Athena", Age: 42})
commandBus.HandleCommand(&AcceptInvite{InvitationID: athenaID})
err = commandBus.HandleCommand(&DeclineInvite{InvitationID: athenaID})
if err != nil {
fmt.Printf("error: %s\n", err)
}
hadesID := eventhorizon.NewUUID()
commandBus.HandleCommand(&CreateInvite{InvitationID: hadesID, Name: "Hades"})
commandBus.HandleCommand(&AcceptInvite{InvitationID: hadesID})
zeusID := eventhorizon.NewUUID()
commandBus.HandleCommand(&CreateInvite{InvitationID: zeusID, Name: "Zeus"})
commandBus.HandleCommand(&DeclineInvite{InvitationID: zeusID})
// Read all invites.
invitations, _ := invitationRepository.FindAll()
for _, i := range invitations {
fmt.Printf("invitation: %#v\n", i)
}
// Read the guest list.
guestList, _ := guestListRepository.Find(eventID)
fmt.Printf("guest list: %#v\n", guestList)
// records := eventStore.FindAllEventRecords()
// fmt.Printf("event records:\n")
// for _, r := range records {
// fmt.Printf("%#v\n", r)
// }
}