播放框架：Dependecy Inject Action Builder [英] Play Framework: Dependecy Inject Action Builder

问题描述

由于Play Framework 2.4有可能使用依赖注入（使用Guice）。

在我使用对象之前（例如 AuthenticationService ）在我的ActionBuilders中：

 对象AuthenticatedAction扩展ActionBuilder [AuthenticatedRequest] {
 override def invokeBlock [A]（请求：请求[A]，块：（AuthenticatedRequest [A]）=>未来[结果]）：未来[结果] = {
 ... 
 AuthenticationService.authenticate（。 ..）
 ... 
} 
} 
  

现在 AuthenticationService 不再是一个对象，而是一个类。我如何仍然使用我的 ActionBuilder 中的 AuthenticationService ？

解决方案

将身份验证服务中的动作构建器定义为抽象字段。然后将它们混合到您的控制器中，您可以向其注入服务。例如：

  trait MyActionBuilders {
 //抽象依赖关系
 def authService：AuthenticationService 
 
 def AuthenticatedAction = new ActionBuilder [AuthenticatedRequest] {
 override def invokeBlock [A]（request：Request [A]，block（AuthenticatedRequest [A]）=> Future [Result]）：Future [结果] = {
 authService.authenticate（...）
 ... 
} 
} 
} 
  / pre> 
 
 
和控制器：
  @Singleton 
类MyController @Inject（）（authService：AuthenticationService）使用MyActionBuilders扩展Controller。{
 def myAction（...）= AuthenticatedAction {implicit request => 
 Ok（authenticated！）
} 
} 
  
 
since Play Framework 2.4 there is the possibility to use dependency injection (with Guice).

Before I used objects (for example AuthenticationService) in my ActionBuilders:
object AuthenticatedAction extends ActionBuilder[AuthenticatedRequest] {
  override def invokeBlock[A](request: Request[A], block: (AuthenticatedRequest[A]) => Future[Result]): Future[Result] = {
    ...
    AuthenticationService.authenticate (...)
    ...
  }
}
Now AuthenticationService is not an object anymore, but a class. How can I still use the AuthenticationService in my ActionBuilder? 
解决方案
Define your action builders inside a trait with the authentication service as an abstract field. Then mix them into your controllers, into which you inject the service. For example:
trait MyActionBuilders {
  // the abstract dependency
  def authService: AuthenticationService

  def AuthenticatedAction = new ActionBuilder[AuthenticatedRequest] {
    override def invokeBlock[A](request: Request[A], block(AuthenticatedRequest[A]) => Future[Result]): Future[Result] = {
      authService.authenticate(...)
      ...
    }
  }
}
and the controller:
@Singleton
class MyController @Inject()(authService: AuthenticationService) extends Controller with MyActionBuilders {    
  def myAction(...) = AuthenticatedAction { implicit request =>
    Ok("authenticated!")
  }
}


                        
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