Realm, ObjectMapper 사용시 JSON Array를 Realm Object List로 변경하기 위해 사용한다.

ArrayTransform.swift

import RealmSwift
import ObjectMapper

class ArrayTransform<T: RealmSwift.Object>: TransformType where T: Mappable {
    typealias Object = List<T>
    typealias JSON = Array<AnyObject>
    
    /**
     - Parameter value: JSON Value
     - Returns: if value is `nil` or not Array will be return empty List<T>
    */
    func transformFromJSON(_ value: Any?) -> Object? {
        let result = Object()
        guard let _value = value,
            let objectArray = _value as? Array<AnyObject> else { return result }

        let mapper = Mapper<T>()
        
        for object in objectArray {
            //if model is `nil` continue to next object
            guard let model = mapper.map(JSONObject: object) else {
                continue
            }
            
            result.append(model)
        }
        
        return result
    }
    
    /**
     - Parameter value: RealmSwift Object
     - Returns: if value is `nil` or empty will be return empty Array<AnyObject>
     */
    func transformToJSON(_ value: Object?) -> JSON? {
        var result = JSON()
        guard let _value = value, _value.count > 0 else { return  result }
        
        result = _value.map { $0 }
      
        
        return result
    }
}

ObjectMapper+Realm에 더 깔끔한 코드가 존재함
ListTransform