Service Logic

[jakobzudrell]

Hey there!

Trying my luck even though there has been no activity here for quite some time...

I've been playing around with go and the WTF application for some time now and one thing I haven't really been able to wrap my head around is where to implement "generic" service logic.

Let's look at an AuthService:

type AuthService interface {
	AuthRepository
	GenerateSessionToken() (string, error)
	ValidateSession(token string) (bool, error)
	InvalidateSession(id uuid.UUID) error
	InvalidateUserSessions(id uuid.UUID) error
}

type AuthRepository interface {
	CreateSession(ctx context.Context, session *Session) (uuid.UUID, error)
	GetSession(ctx context.Context, id uuid.UUID) (*Session, error)
	DeleteSession(ctx context.Context, id uuid.UUID) error
	UpdateSession(ctx context.Context, session *Session) error
}

I picked this up in another discussion here. The AuthService is a superset of the AuthRepository, latter only implementing CRUD operations whilst the AuthService supports some more generic stuff such as generating a token or validating a session - let's keep this design in mind for later...

Moving on, the application supports multiple database backends which are abstracted by a Driver interface:

type Driver interface {
	GetDB() *sql.DB
	Open() error
	Close() error

	// The repositories that must be implemented
	NewUserRepository() cuenta.UserRepository
	NewAuthRepository() cuenta.AuthRepository
}

Each backend implementing the database driver, will have to support my domain model repositories.

Having the Service and Repository separated, I can reduce the codebase in the DB implementations to really only the minimal CRUD operations. But now I don't know where the rest of the AuthService should be implemented...

In my imagination, I'd have a small small auth package, that operates independent of any http or sql package and provides the AuthService.

So basically like this:

1. main creates a DB backend which provides NewAuthRepository
2. main creates an auth service using NewAuthService from the auth package
3. main passes the AuthService to http which can then run "generic" methods, such as GenerateSessionToken() and/or run CRUD operations against the AuthRepository...

Any opinions on this?