exhibit-a.scala

// kinja-service library

trait SsoServiceComponent extends ServiceComponent {

    val ssoService: SsoService
    
    class SsoService extends Service {
        def authorByToken(token: String): Author = {
            lookupAuthorInDatabase(token)
        }
    }

}

trait InvitesServiceComponent extends ServiceComponent {
    self: SsoServiceComponent =>
    
    val invitesService: InvitesService
    
    class InvitesService extends Service {
        def invite(token: String, invitee: Author): Unit = {
            val inviter = ssoService.authorByToken(token)
            saveInvitationToDatabase(inviter, invitee)
        }
    }
    
}



// kinja-core application

object ServiceContext extends SsoServiceComponent with InvitesServiceComponent {
    val ssoService = new SsoService
    val invitesService = new InvitesService
}

object InvitesController extends Controller {
    
    // mapped to route /api/invite/$authorId
    def invite(token: String, invitee: Author) = Action {
        ServiceContext.invitesService.invite(token, invitee)
    }
    
}