Implement Content Negotiation feature

Currently, if I want to send back a response in JSon, I have to do

install(GsonSupport)

This feels like it’s coupling a specific implementation of Json encoding with the feature of actually representing a response with a specific content type.

Considering generalising this support with something more generic such as

install(AutoContentType)

and register different content types with specific serialisers/deserialisers. For instance

register("application/json", GsonSerialiser)
register("application/xml", XmlSerialiser)

and then allow the respond call to specify the content type

call.respond(listOf(myStuff), "application/json")

which will be picked up by the correct serialiser.

[orangy]

@McPringle agree, that’s the plan. It should be something like this:

install(AutoContent) {
   register(ContentType.Application.Json, GsonConverter)
}

routing { 
   get("/api/user/{id}") {
      val id = call.parameters["id"]
      val user = db.getUser(id)
      call.respond(user)
   }
}

(error handling omitted for clarity)

Same for call.receive<User>() for POST data.

[cy6erGn0m]

Please see http://ktor.io/features/content-negotiation.html for details.