saga

Documentation

Index

• type Error
  • func (e Error) Cause() error
  • func (e Error) Error() string
  • func (e Error) Unwrap() error
• type EventHandler
  • func NewEventHandler(saga Saga, commandHandler eh.CommandHandler) *EventHandler
  • func (h *EventHandler) HandleEvent(ctx context.Context, event eh.Event) error
  • func (h *EventHandler) HandlerType() eh.EventHandlerType
• type Saga
• type Type
  • func (t Type) String() string

Types

type Error

type Error struct {
	// Err is the error that happened when projecting the event.
	Err error
	// Saga is the saga where the error happened.
	Saga string
}

Error is an error in the projector.

func (Error) Cause

func (e Error) Cause() error

Cause implements the github.com/pkg/errors Unwrap method.

func (Error) Error

func (e Error) Error() string

Error implements the Error method of the errors.Error interface.

func (Error) Unwrap

func (e Error) Unwrap() error

Unwrap implements the errors.Unwrap method.

type EventHandler

type EventHandler struct {
	// contains filtered or unexported fields
}

EventHandler is a CQRS saga handler to run a Saga implementation.

func NewEventHandler

func NewEventHandler(saga Saga, commandHandler eh.CommandHandler) *EventHandler

NewEventHandler creates a new EventHandler.

func (*EventHandler) HandleEvent

func (h *EventHandler) HandleEvent(ctx context.Context, event eh.Event) error

HandleEvent implements the HandleEvent method of the eventhorizon.EventHandler interface.

func (*EventHandler) HandlerType

func (h *EventHandler) HandlerType() eh.EventHandlerType

HandlerType implements the HandlerType method of the eventhorizon.EventHandler interface.

type Saga

type Saga interface {
	// SagaType returns the type of the saga.
	SagaType() Type

	// RunSaga handles an event in the saga that can return commands.
	// If an error is returned from the saga, the event will be run again.
	RunSaga(context.Context, eh.Event, eh.CommandHandler) error
}

Saga is an interface for a CQRS saga that listens to events and generate commands. It is used for any long lived transaction and can be used to react on multiple events.

type Type

type Type string

Type is the type of a saga, used as its unique identifier.

func (Type) String

func (t Type) String() string

String returns the string representation of a saga type.