How to edit existing JSON object with sprayJSON - json

Question

I am using akka with spray json support for which I need to edit value in the recieved json.
import akka.http.scaladsl.server.Directives
import akka.http.scaladsl.marshallers.sprayjson.SprayJsonSupport
import spray.json._
final case class Item(name: String, id: Long)
final case class Order(items: List[Item],orderTag:String)
trait JsonSupport extends SprayJsonSupport with DefaultJsonProtocol {
implicit val itemFormat = jsonFormat2(Item)
implicit val orderFormat = jsonFormat2(Order)
}
In my use case I recieve the json with orderTag value as null, all I need to do is edit the orderTag value with and then use it as entity value.Is it possible to write/edit jsonObject and How to do that ?
class MyJsonService extends Directives with JsonSupport {
// format: OFF
val route =
get {
pathSingleSlash {
complete(Item("thing", 42)) // will render as JSON
}
} ~
post {
entity(as[Order]) { order => // will unmarshal JSON to Order
val itemsCount = order.items.size
val itemNames = order.items.map(_.name).mkString(", ")
complete(s"Ordered $itemsCount items: $itemNames")
}
}
}

Answer 1

You can just edit the json AST like ..
val json = """{"orderTag":null}"""
val jsVal = json.parseJson
val updatedJs = if (jsObj.fields.get("orderTag") == Some(JsNull)) {
JsObject(jsObj.fields + ("orderTag" -> JsString("new tag")))
} else {
jsObj
}
updatedJs.compactPrint
res26: String = """
{"orderTag":"new tag"}
"""