Nested array of double in realm (swift) - ios

Question

I have this JSON:
{
"location": {
"position": {
"type": "Point",
"coordinates": [
45.579553,
11.751805
]
}
}
}
Which belongs to another JSON object.
Trying to map it with Realm and ObjectMapper, I am findind difficulties mapping the coordinates property which is an array of double.
That's what reading the documentation and S.O. seems to have sense:
import Foundation
import RealmSwift
import ObjectMapper
class Coordinate:Object, Mappable{
dynamic var latitude:Double = 0.0
dynamic var longitude:Double = 0.0
required convenience init?(_ map: Map) {
self.init()
}
func mapping(map: Map) {
latitude <- map[""]
longitude <- map[""]
}
}
class Position: Object, Mappable{
var type:String = ""
var coordinates:Coordinate?
required convenience init?(_ map: Map) {
self.init()
}
func mapping(map: Map) {
type <- map["type"]
coordinates <- map["coordinates"]
}
}
class Location: Object, Mappable{
dynamic var id = ""
dynamic var position:Position?
dynamic var desc = ""
override static func indexedProperties()->[String]{
return["id"]
}
override class func primaryKey() -> String? {
return "id"
}
required convenience init?(_ map: Map) {
self.init()
}
func mapping(map: Map) {
id <- map["id"]
position <- map["position"]
}
}
However I'm stuck in understanding how to map the "coordinates" object. Please note that this problem has nothing to do with ObjectMapper itself, it's more of a question on how to assign an array of Double to a property in a Realm model.

Answer 1

I was able to solve this following the indications in this issue:
https://github.com/realm/realm-cocoa/issues/1120 (credits #jazz-mobility)
class DoubleObject:Object{
dynamic var value:Double = 0.0
}
class Position: Object, Mappable{
var type:String = ""
var coordinates = List<DoubleObject>()
required convenience init?(_ map: Map) {
self.init()
}
func mapping(map: Map) {
type <- map["type"]
var coordinates:[Double]? = nil
coordinates <- map["coordinates"]
coordinates?.forEach { coordinate in
let c = DoubleObject()
c.value = coordinate
self.coordinates.append(c)
}
}
}

Answer 2

You can now simply use List<Double>() without it storing an object.
More information can be found here: https://academy.realm.io/posts/realm-list-new-superpowers-array-primitives/

Answer 3

#objcMembers class RealmObject: Object, Mappable {
dynamic var listValues = List<MyRealmObject>()
required convenience init?(map: Map) {
self.init()
}
// Mappable
func mapping(map: Map) {
listValues <- (map["listValues"], RealmlistObjectTransform())
}
}
#objcMembers class MyRealmObject: Object, Mappable {
required convenience init?(map: Map) {
self.init()
}
// Mappable
func mapping(map: Map) {
}
}
class RealmlistObjectTransform: TransformType {
typealias Object = List<MyRealmObject> // My Realm Object here
typealias JSON = [[String: Any]] // Dictionary here
func transformFromJSON(_ value: Any?) -> List<MyRealmObject>? {
let list = List<MyRealmObject>()
if let actors = value as? [[String: Any]] {
let objects = Array<MyRealmObject>(JSONArray: actors)
list.append(objectsIn: objects)
}
return list
}
func transformToJSON(_ value: List<MyRealmObject>?) -> [[String: Any]]? {
if let actors = value?.sorted(byKeyPath: "").toArray(ofType: MyRealmObject.self).toJSON() {
return actors
}
return nil
}
}