ReactiveMongo: How to convert a BSONArray to List[String] - mongodb

Question

Given the following BSONDocument...
val values = BSONDocument("values" -> BSONArray("one", "two", "three"))
How do I convert it to a List? I've tried this...
values.getAs[List[String]]("values").getOrElse(List.empty))
... but it doesn't work - I always get List.empty.
Am I missing something?
EDIT
OK... I think it is worth describing the real case. I ran the distinct command and this was the result:
values: {
values: [
0: BSONObjectID("55d0f641a100000401b7e454")
],
stats: {
n: BSONInteger(1),
nscanned: BSONInteger(1),
nscannedObjects: BSONInteger(1),
timems: BSONInteger(0),
cursor: BSONString(BtreeCursor projectId_1)
},
ok: BSONDouble(1.0)
}
I need to transform values to a Scala List[String] like this:
List("55d0f641a100000401b7e454")

Answer 1

Here is my solution. First, I've defined a BSONReader[BSONValue, String] like this...
package object bsonFormatters {
implicit object BSONValueStringReader extends BSONReader[BSONValue, String] {
def read(bson: BSONValue) = bson match {
case oid: BSONObjectID => oid.stringify
}
}
... and then just imported it in my companion object like this:
import reactivemongo.bson.{BSONString, BSONDocument}
import reactivemongo.core.commands.{CommandError, BSONCommandResultMaker, Command}
case class Distinct(
collectionName: String,
field: String,
query: Option[BSONDocument] = None
) extends Command[Seq[String]] {
override def makeDocuments = BSONDocument(
"distinct" -> BSONString(collectionName),
"key" -> field,
"query" -> query
)
val ResultMaker = Distinct
}
object Distinct extends BSONCommandResultMaker[Seq[String]] {
import bsonFormatters._ // this makes the trick
def apply(document: BSONDocument) = CommandError.checkOk(
document,
Some("distinct")
).toLeft(
document.getAs[List[String]]("values").getOrElse(List.empty)
)
}
I hope it helps.