Here is the solution:
def find(selector: JsValue, projection: Option[JsValue]) = {
var query = collection.genericQueryBuilder.query(selector)
projection.map(query = query.projection(_))
query.cursor[JsValue].collect[Vector](perPage).transform(
success => success,
failure => failure match {
case e: LastError => DaoException(e.message, Some(DATABASE_ERROR))
}
)
}
or alternatively:
def find(selector: JsValue, projection: Option[JsValue]) = {
val query = collection.genericQueryBuilder
.query(selector)
.projection(projection.getOrElse(Json.obj())
query.cursor[JsValue].collect[Vector](perPage).transform(
success => success,
failure => failure match {
case e: LastError => DaoException(e.message, Some(DATABASE_ERROR))
}
)
}
I hope that helps.