如何在Play + Scala中为自定义对象定义json编写器?

本文介绍了如何在Play + Scala中为自定义对象定义json编写器?的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

您能否演示一下如何在Scala和Play Framework 2.1-RC2中为我的课程定义json writer?

Could you please demostrate how I can define json writer for my class in Scala and Play Framework 2.1-RC2 ?

文档非常混乱(并且将成为Web开发人员社区广泛采用Scala/Play的重大障碍).例如，不仅不清楚确切的以下代码在哪里(摘自 此处 )应该位于

The documentation is quite confusing (and will be significant obstacle for wider adoption of Scala/Play by web-developer community). For example not only it's unclear where exactly following code (taken from here) should be located

implicit val taskWrites = ( (__ \ "id").write[String] ~ (__ \ "label").write[Boolean] ~ )(unlift(Task.unapply))

，但是如果我将其放在object定义中，它也是不可编译的.播放给我以下错误

but it's also not compilable if I put it inside object definition. Play gives me following error

not found: value __

这是我的Task.scala

Here is my Task.scala

pastebin/hG8F6Gqk

推荐答案

嗯，事实证明问题很明显.我忘了导入play.api.libs.functional.syntax._.

Well, turned out the problem was obvious. I forgot to import play.api.libs.functional.syntax._.