Realm + Swift，嵌套JSON

Question

I have a problem since last 2 days. I can't get my JSON transformed to a Realm Object.

I have a json like below:

{
  "gender" : "male",
  "id" : "123456789",
  "age_range" : {
    "min" : 21
  },
  "last_name" : "LastName" 
}

I have this Realm Models:

class UserObject: Object {

    dynamic var userId: String = ""
    dynamic var lastName: String?
    dynamic var gender: String?
    var ageRange = List<AgeRangeObject>()

    required convenience init?(_ map: Map) {
        self.init()
    }
}

class AgeRangeObject: Object {

    dynamic var min: Int = 0
}

And the way I am trying to create an instance of this model with ObjectMapper to parse json to dictionary and then create the model instance:

    let userJSONModel = Mapper<User>().map(jsonString)

    let realm = try! Realm()

    do {
        try realm.write {

            let dict: [String : AnyObject] = [
                "userId" : (userJSONModel?.userId)!,
                "ageRange" : (userJSONModel?.ageRange)!,
                "lastName" : (userJSONModel?.lastName)!,
                "gender" : (userJSONModel?.gender)!
            ]

            let userModel = UserObject(value: dict)

            realm.add(userModel)
        }
    } catch {
        print("Exception")
    }

The problem occurs on this line: let userModel = UserObject(value: dict)

I get the folowing error:

*** Terminating app due to uncaught exception 'RLMException', reason: 'Invalid value 'min' to initialize object of type 'AgeRangeObject': missing key 'min''

I was looking on the stackoverflow:

Nested Arrays throwing error in realm.create(value: JSON) for Swift

How to convert Realm object to JSON with nested NSDate properties?

but my case is different. Do you know what's the problem with that age range dictionary? Why it can't parse it well? Thank you.

Answer 1

In your JSON, ageRange is a dictionary, whereas the UserObject.ageRange property is a List<AgeRangeObject> . You have mismatched models.

You either need to update your models to reflect the structure of your JSON:

var ageRange = List<AgeRangeObject>()

becomes

dynamic var ageRange: AgeRangeObject? = nil

or vice versa, update your JSON to reflect the structure of your models:

{
  "gender" : "male",
  "id" : "123456789",
  "age_range" : [{
    "min" : 21
  }],
  "last_name" : "LastName" 
}

Answer 2

{
  "key1" : "value1",
  "key2" : "value2",
  "array1" : [{
    "key" : value
  }],
 "key3" : "value3" 
}

For this you could use ObjectMapper's TransformType.

Reference: https://github.com/APUtils/ObjectMapperAdditions

My Code:

@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
    }
  }