How to unmarshall a list of case class in Spray

Question

First time Spray user failing to find any proper examples on this anywhere. I'm looking to unmarshall the XML API response that contains a List[Person].

Say case class Person(name: String, age: Int). The unmarshaller should produce the appropriate List[Person].

Spray has a default NodeSeqUnmarshaller but I can't figure out how to chain things properly, would be grateful for any pointers.

Have you defined a JsonFormat for your case class, as defined here: https://github.com/spray/spray-json#providing-jsonformats-for-case-classes ? — lpiepiora, Feb 23 '15 at 16:36
@lpiepiora Not sure what that has to do with XML unmarshalling. — flavian, Feb 23 '15 at 16:45
ah, sorry my bad for whatever reason I thought you're talking about JSON, forget about it — lpiepiora, Feb 23 '15 at 16:52
@flavian, Is Daryl's answer correct? Did you forget to accept it? — AmigoNico, May 21 '15 at 18:20

Daryl Odnert · Accepted Answer · 2015-02-24T00:02:05.913

I had to solve this problem in my application. Here is some code based on your example case class that you might find to be helpful.

My approach uses Unmarshaller.delegate as discussed here.

import scala.xml.Node
import scala.xml.NodeSeq
import spray.httpx.unmarshalling._
import spray.httpx.unmarshalling.Unmarshaller._

case class Person(name: String, age: Int)

object Person {
  def fromXml(node: Node): Person = {
    // add code here to instantiate a Person from a Node
  }
}

case class PersonSeq(persons: Seq[Person])

object PersonSeq {
  implicit val PersonSeqUnmarshaller: Unmarshaller[PersonSeq] = Unmarshaller.delegate[NodeSeq, PersonSeq](MediaTypes.`text/xml`, MediaTypes.`application/xml`) {
    // Obviously, you'll need to change this function, but it should
    // give you an idea of how to proceed.
    nodeSeq =>
      val persons: NodeSeq = nodeSeq \ "PersonList" \ "Person"
      PersonSeq(persons.map(node => Person.fromXml(node))
  }
}

Thanks for this, found the delegate method in the mean time. — flavian, Feb 23 '15 at 23:42
@flavian - Please "accept" my answer, if you agree that it's the way to solve the problem. Thanks. — Daryl Odnert, Feb 23 '15 at 23:52

How to unmarshall a list of case class in Spray

1 Answers1