NodeSeqMarshaller with ContentType charset not resolving - scala

Question

Attempting to get a spray endpoint negotiating a postman request for content. My XML marshaller seems to let me down, ie, it never resolves the correct marshaller option based on Accept header and charset.
I have the following:
object ResponseVO {
val NodeSeqMarshaller = Marshaller.delegate[ResponseVO, NodeSeq](ContentType(`text/xml`, `UTF-8`)) { respVO => <ussd><type>{ respVO.respType }</type><message>{ respVO.message }</message></ussd> }
val supportedContentTypes = List[ContentType](ContentType(`text/xml`, `UTF-8`))
implicit val marshaller = Marshaller[ResponseVO] { (respVO, ctx) =>
ctx.tryAccept(supportedContentTypes) match {
case Some(ContentType(`text/xml`, `UTF-8`)) => NodeSeqMarshaller(respVO, ctx)
case whatever => println(whatever); ctx.rejectMarshalling(supportedContentTypes);
}
}
}
and the following route:
trait USSDRoute {
this: SimpleRoutingApp with BootStrappedActorSystem =>
val ussdRoute = path("ussd") {
parameters('msisdn.as[Long], 'session.as[String], 'type.as[Int], 'msg.as[String], 'network.as[Int]) { (msisdn, session, reqType, msg, network) =>
complete {
val reqVO = RequestVO(msisdn, session, reqType, msg, network)
println(s"received $reqVO")
ResponseVO(1, "Spirit midget medium escapes from prison, headlines read: Small medium at large!")
}
}
}
}
Unfortunately I never seem to negotiate correctly, ie, my marshaller resolution will dive bomb into the "whatever" block and respond with a 406
"Resource representation is only available with these Content-Types:
text/xml; charset=UTF-8"
I am using Postman and my request headers read:
GET /ussd?msisdn=0794138690&type=1&network=4&msg=hello&session=99 HTTP/1.1
Host: localhost:9999
Connection: keep-alive
Accept: text/xml; charset=UTF-8
Cache-Control: no-cache
User-Agent: Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML,
like Gecko) Chrome/40.0.2214.91 Safari/537.36
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8,nl;q=0.6
It's probably something small and silly - hopefully someone can help steer me in the right direction.
Thank you

Answer 1

Have a look at how the case class ContentType is defined:
case class ContentType(mediaType: MediaType, definedCharset: Option[HttpCharset])
Note that definedCharset is defined as an Option[HttpCharset], therefore your pattern match via
case Some(ContentType(`text/xml`, `UTF-8`)) => ...
never can succeed. So you need to use a Some to perform the pattern match successfully:
case Some(ContentType(`text/xml`, Some(`UTF-8`))) => ...