玩！框架 - 将多个列表返回到模板

Question

我有3个课程，我想将3个列表返回到Form中使用的模板 我的数据库是MongoDB

def addCourse = Action.async {implicit request =>
  val teacherCollection = db.collection[BSONCollection]("Teacher")
   val courseColl = subjectCollection.find(BSONDocument()).cursor[Subject].collect[List]()
   val teacherColl = teacherCollection.find(BSONDocument()).cursor[Teacher].collect[List]()

    courseColl.map { course =>
      val sam = teacherColl.map{teacher=>
        teacher
      }
    Ok(views.html.Course.addNewCourse(course,sam,Course.form))
   }
  }

模板代码：

   @(subject:List[models.Subject],teacher:List[models.Teacher],myForm: Form[models.Course])

我有一个错误：类型不匹配期望列表[老师]，实际未来[列表[老师]]

我该怎么办？

注意：如果我把Ok（views ...）放到val sam map中，编译器显示错误，它听起来像异步错误因为＃as;＆＃34; async＆＃34;将是红色

 Error:(59, -1) Play 2 Compiler: 
 /app/controllers/School.scala:59: type mismatch;
found   : Unit
  required: play.api.mvc.Result

Answer 1

我用flatMap修复了这个问题

courseColl.flatMap { course =>
  teacherColl.flatMap { teacher =>
    semesterColl.map { semester =>
      Ok(views.html.Course.addNewCourse(course, teacher, semester,    Course.form))
    }
  }
}