using Newtonsoft.Json.Linq;

using Newtonsoft.Json;

using System;

using System.Collections.Generic;

using System.Linq;

​

namespace JsonConverterx

{

    class Program

    {

        static void Main(string[] args)

        {

            Console.WriteLine("Hello World!");

            var o = new Employee{FirstName = "John", LastName = "Doe", Role = new Role{Name = "Foo", Priviledges = new[]{new Priviledge{Name = "Hoo"}}}};

            string json = JsonConvert.SerializeObject(o, Formatting.Indented, new NestedJsonConverter(typeof(Employee)));

            json.Dump();

        }

    }

​

    public class NestedJsonConverter : JsonConverter

    {

        private readonly Type[] _types;

        public NestedJsonConverter(params Type[] types)

        {

            _types = types;

        }

​

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)

        {

            JToken t = JToken.FromObject(value);

            if (t.Type != JTokenType.Object)

            {

                t.WriteTo(writer);

            }

            else

            {

                JObject o = (JObject)t;

                writer.WriteStartObject();

                void writeNested(JObject target, object source, string prefix)

                {

                    target.Properties().ToList().ForEach(p =>

                    {

                        var prop = source.GetType().GetProperty(p.Name);

                        var value = prop.GetValue(source);

                        var prefixed = string.IsNullOrEmpty(prefix) ? p.Name : $"{prefix}_{p.Name}";

                        if (p.Value.Type == JTokenType.Object)

                        {

                            writeNested((JObject)p.Value, value, prefixed);

                        }

                        else if (p.Value.Type == JTokenType.Array)

                        {

                            var arr = (JArray)p.Value;

                            writer.WritePropertyName(prefixed);

                            arr.WriteTo(writer);

                        }

                        else

                        {

                            writer.WritePropertyName(prefixed);

                            writer.WriteValue(value);

                        }

                    }

​

                    );

                }

​

                writeNested(o, value, "");

                writer.WriteEndObject();

            }

        }

​

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)

        {

            throw new NotImplementedException("Unnecessary because CanRead is false. The type will skip the converter.");

        }

​

        public override bool CanRead

        {

            get

            {

                return false;

            }

        }

​

        public override bool CanConvert(Type objectType)

        {

            return _types.Any(t => t == objectType);

        }

    }

​

    public class Employee

    {

        public string FirstName

        {

            get;

            set;

        }

​

        public string LastName

        {

            get;

            set;

        }

​

        public Role Role

        {

            get;

            set;

        }

    }

​

    public class Role

    {

        public string Name

        {

            get;

            set;

        }

​

        public Priviledge[] Priviledges

        {

            get;

            set;

        }

    }

​

    public class Priviledge

    {

        public string Name

        {

            get;

            set;

        }

    }

}