Question

在models包中，我具有以下案例类：

case class Property (id: Option[Long],
                 address: String,
                 postCode: Int,
                 latitude: Double,
                 longitude: Double,
                 surface: Option[Int],
                 bedRoomCount: Option[Int])

object Property {
    implicit val propertyFormat = Json.format[Property]
}

我正在尝试配置传递Property对象的路由：

POST    /update-property            controllers.PropertyController.update(property: models.Property)

我的控制器定义了一个动作：

def update(property: Property) = Action.async { implicit request =>
 ...bla bla bla...
}

我收到以下编译错误：

[error] conf/routes:8:1: No QueryString binder found for type models.Property. Try to implement an implicit QueryStringBindable for this type.
[error] POST    /update-property            controllers.PropertyController.update(property: models.Property)
[error] conf/routes:8:1: not enough arguments for method implicitly: (implicit e: play.api.mvc.QueryStringBindable[models.Property])play.api.mvc.QueryStringBindable[models.Property].
[error] Unspecified value parameter e.

我想念什么？可以用property数据填充表单吗？

Answer 1

就像编译错误指出的那样，您需要实现implicit QueryStringBindable。像这样：

object Binders {

  //return the error message on the left should the parsing fail
  private def propertyFromString(s: String): Either[String, Property] = ???

  private def propertyToString(property: Property): String = ???

  implicit def queryStringBindable(implicit stringBinder: QueryStringBindable[String]): QueryStringBindable[Property] = new QueryStringBindable[Property] {
    override def bind(key: String, params: Map[String, Seq[String]]): Option[Either[String, Property]] = {
      for {
        eitherPropString <- stringBinder.bind("property", params)
      } yield {
        eitherPropString match {
          case Right(propString) => propertyFromString(propString)
          case _ => Left("Unable to bind property")
        }
      }
    }
    override def unbind(key: String, property: Property): String = {
      stringBinder.unbind("property", propertyToString(property))
    }
  }

}

对于???，您将需要编写代码以将Property与String进行编码/解码。然后，在您的build.sbt文件中，添加

routesImport += "path.to.Binders._"

，以便您的routes文件可以访问您的Binders对象。该文档为here。相反，如果您想将Property字段作为单独的查询参数传递，请参阅文档中的AgeRange示例。

Scala Play Framework 2.6-定义使用自定义对象的路由

1 个答案: