Action composition

https://github.com/playframework/play-samples/blob/2.8.x/play-scala-rest-api-example/app/v1/post/PostActionBuilder.scala 처럼 ActionBuilder 를 만드는 것도 좋은 것 같다.

 

package controllers

import play.api.Logging
import play.api.mvc._

import javax.inject._
import scala.concurrent.{ExecutionContext, Future}

class CustomAction @Inject() (parser: BodyParsers.Default)(implicit ec: ExecutionContext)
    extends ActionBuilderImpl(parser)
    with Logging {
  override def invokeBlock[A](request: Request[A], block: (Request[A]) => Future[Result]): Future[Result] = {
    println("Start Custom Action")
    block(request)
  }
}

case class AuthRequest[A](username: String, request: Request[A]) extends WrappedRequest[A](request)

object MyActionRefiner {
  def auth(implicit ec: ExecutionContext): ActionRefiner[Request, AuthRequest] =
    new ActionRefiner[Request, AuthRequest] {
      override protected def refine[A](request: Request[A]): Future[Either[Result, AuthRequest[A]]] =
        Future.successful(Right(AuthRequest("windbird", request)))

//    override protected def refine[A](request: Request[A]): Future[Either[Result, AuthRequest[A]]] =
//      Future.successful(Left(Unauthorized("Not Permitted")))

      override protected def executionContext: ExecutionContext = ec
    }
}

@Singleton
class ApiController @Inject() (cc: ControllerComponents, customAction: CustomAction)(
  implicit ec: ExecutionContext
) extends AbstractController(cc) {
  def api: Action[AnyContent] =
    Action.andThen(MyActionRefiner.auth)((request: AuthRequest[AnyContent]) => Ok(s"allowed user ${request.username}"))
//    customAction.andThen(MyActionRefiner.auth)((request: AuthRequest[AnyContent]) => Ok(s"allowed user ${request.username}"))
}

 

설명

ActionBuiler 끼리도 andThen 으로 composition 할 수 있다.

customAction.andThen(customAction2)...

 

참고: http://www.tzavellas.com/techblog/2015/02/10/action-composition-in-play-framework/