gistfile1.scala

// the enumeration
object WeekDay extends Enumeration {
  type WeekDay = Value
  val Mon = Value("Monday")
  val Tue = Value("Tuesday")
  val Wed = Value("Wednesday")
  val Thu = Value("Thursday")
  val Fri = Value("Friday")
  val Sat = Value("Saturday")
  val Sun = Value("Sunday")
}

// the case class containing an enum
case class JobStart(name: String, start: WeekDay.Value)

// sjson serialization protocol
// instance of the typeclass
object JobStartProtocol extends DefaultProtocol {
  import dispatch.json._
  import JsonSerialization._
  implicit object JobStartFormat extends Format[JobStart] {
    def reads(json: JsValue): JobStart = json match {
      case JsObject(m) =>
        JobStart(fromjson[String](m(JsString("name"))), 
          WeekDay.withName(fromjson[String](m(JsString("start")))))
      case _ => throw new RuntimeException("JsObject expected")
    }
    def writes(p: JobStart): JsValue =
      JsObject(List(
        (tojson("name").asInstanceOf[JsString], tojson(p.name)), 
        (tojson("start").asInstanceOf[JsString], tojson(p.start.toString)))) 
  }
}

// scalatest test case
describe("Serialization of enumerated values") {
  it("should serialize") {
    import JobStartProtocol._
    val js = JobStart("Debasish", WeekDay.Mon)
    fromjson[JobStart](tojson(js)) should equal(js)
  }
}