spray implicit allowing spray DateTimes to be deserialized from parameters directives

EventService.scala

import spray.http.DateTime
import spray.httpx.unmarshalling._

/*
 * Implicit allowing spray DateTimes to be deserialized from parameters directives.
 *
 * See: http://spray.io/documentation/1.2.2/spray-httpx/unmarshalling/
 */

// type FromStringOptionDeserializer[T] = Deserializer[Option[String], T]
implicit def string2DateTime = new FromStringOptionDeserializer[DateTime] {
  def apply(value: Option[String]): Deserialized[DateTime] = value match {
    case None      => Left(ContentExpected)
    case Some(str) =>
      DateTime.fromIsoDateTimeString(str) toRight (new MalformedContent("invalid datetime format"))
  }
}

// This is equivalent, by virtue of `fromFunction2Converter` (which wraps the
// unsafe `get` here in a try), and the Option-lifting implicits found in
// `spray.httpx.unmarshalling.Deserializer`. Lotsa magic.
implicit def string2DateTime(str: String): DateTime =
  DateTime.fromIsoDateTimeString(str).get


val route =
  path("something") {
    get {
      parameters('start.as[DateTime], 'end.as[DateTime]) { (start, end) =>
        // ...
      }
    }
  }