lephuocmy668/cqrskit

CQRS+ES foundation libary for building applications.

CQRSKit

CQRSKit provides a base libary that implements a simple but extensive Event Sourcing + CQRS library. It's purpose is to provide multi-store event stores with a simple but robust API for handling CQRS style APIs. It is heavily inspired by John Oliver's EventStore.

Install

go get github.com/gokit/cqrskit/...

Storage Supported

Below are the available database able to be used as the event store technologies:

• MongoDB
• BadgerDB (Planned)
• PostgreSQL (Planned)

Publisher Supported

Below are the implemented queueing technology available for use

• NATS
• Amazon SQS
• NSQ (Planned)
• Redis (Planned)

CLI Tooling

CQRSKit comes bundled with a command line code generation tool, that provides a means of avoiding the usage of reflect by generating an appropriate method on structs annotated with @escqrs to handle different events types, based on methods that have the HandlePrefix, except in cases there such methods have a @escqrs-skip annotation in comments.

//@escqrs
type User struct {
	Version  int
	Email    string
	Username string
}

type UserEmailUpdated struct {
	New string
}

func (u *User) HandleUserEmailUpdated(ev UserEmailUpdated) error {
	return nil
}

func (u *User) HandleUserNameUpdated(ev events.UserNameUpdated) error {
	return nil
}

//@escqrs-method-skip
func (u *User) HandleUserRackUpdated(ev UserEmailUpdated) error {
	return nil
}

Where the above produces the following after running cqrskit generate in terminal:

var (
	// UserAggregateID represents the unique aggregate id for all events
	// related to the User type. It is the typeName hashed using a md5 sum.
	UserAggregateID = "f7091ac77d9b52a3ec5609891cd9f54f"
)

//*******************************************************************************
// User Event Applier
//*******************************************************************************

// Apply embodies the internal logic necessary to apply specific events to a User by
// calling appropriate methods.
func (u *User) Apply(evs cqrskit.EventCommit) error {
	for _, event := range evs.Events {
		switch ev := event.Data.(type) {
		case UserEmailUpdated:
			return u.HandleUserEmailUpdated(ev)
		case events.UserNameUpdated:
			return u.HandleUserNameUpdated(ev)

		}
	}
	return nil
}