JSON List to Scala List - json

Question

I am creating a backend API with Play Framework and Scala. I would like to map the incoming request to a scala object. One of the instance variables of the object is a list of channels. Here is what I currently have:
Controller method that takes the request and attempts to map it to a user:
def addUser = Action(parse.json) { request =>
request.body.validate[User].fold({ errors =>
BadRequest(Json.obj(
"status" -> "Error",
"message" -> "Bad JSON",
"details" -> JsError.toFlatJson(errors)
))
}, { user =>
User.create(user.pushToken, user.channels)
Ok(Json.obj("status" -> "OK", "message" -> "User created"))
})
}
User case class:
case class User(id: Pk[Long], pushToken: String, channels: List[String])
User formatter:
implicit val userFormat = (
(__ \ "id").formatNullable[Long] and
(__ \ "pushToken").format[String] and
(__ \ "channels").format[List[String]]
)((id, pushToken, channels) => User(id.map(Id(_)).getOrElse(NotAssigned), pushToken, channels),
(u: User) => (u.id.toOption, u.pushToken, u.channels))
User anorm create method:
def create(pushToken: String, channels: List[String]) {
DB.withConnection { implicit c =>
SQL("insert into user (pushToken, channels) values ({pushToken}, {channels})").on(
'pushToken -> pushToken,
'channels -> channels
).executeUpdate()
}
}
When I try to compile, I get:
Compilation error[could not find implicit value for parameter extractor: anorm.Column[List[String]]]
Ideally, I would like to be able to accept this as a user:
{
"pushToken":"4jkf-fdsja93-fjdska34",
"channels": [
"channelA", "channelB", "channelC"
]
}
and create a user from it.

Answer 1

You can't use List[String] as column value in Anorm, thats the problem
You should use mkString method or smth else