questions/49846209/deserialize-a-value-serialized-in-two-different-ways-with-json-net

CSharp · Console

/Program.cs

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Runtime.Serialization.Formatters;
using System.IO;
using System.Data;
using System.ComponentModel.DataAnnotations;
using System.Globalization;


using Newtonsoft.Json;
using Newtonsoft.Json.Linq;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Serialization;	

    //https://stackoverflow.com/questions/49846209/deserialize-a-value-serialized-in-two-different-ways-with-json-net
    [JsonConverter(typeof(ValuesConverter))]
    public class Values
    {
        public int BestValue { get; set; }
        public List<string> AllValues { get; set; }
    }

    internal class ValuesConverter : JsonConverter
    {
        public override bool CanConvert(Type objectType)
        {
            return typeof(Values).IsAssignableFrom(objectType);
        }

        public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
        {
            var tokenType = reader.SkipComments().TokenType;
            if (tokenType == JsonToken.Null)
                return null;
            var value = existingValue as Values ?? (Values)serializer.ContractResolver.ResolveContract(objectType).DefaultCreator();
            if (tokenType == JsonToken.Date)
            {
                // Avoid annoying bug that converts date strings to local format described in 
                // https://stackoverflow.com/questions/35166060/json-net-get-specific-json-date-value
                value.AllValues = new List<string> { JToken.Load(reader).ToString(Formatting.None).Trim('"') };
            }
            else if (tokenType.IsPrimitive())
            {
                value.AllValues = new List<string> { (string)JToken.Load(reader) };
            }
            else
            {
                serializer.Populate(reader, value);
            }
            return value;
        }


        public override bool CanWrite { get { return false; } }

        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException();
        }
    }

    public static partial class JsonExtensions
    {
        public static JsonReader SkipComments(this JsonReader reader)
        {
            while (reader.TokenType == JsonToken.Comment && reader.Read())
                ;
            return reader;
        }
		
        public static bool IsPrimitive(this JsonToken tokenType)
        {
            switch (tokenType)
            {
                case JsonToken.Integer:
                case JsonToken.Float:
                case JsonToken.String:
                case JsonToken.Boolean:
                case JsonToken.Undefined:
                case JsonToken.Null:
                case JsonToken.Date:
                case JsonToken.Bytes:
                    return true;
                default:
                    return false;
            }
        }
    }

    public class ValuesSubclass : Values
    {
		public string SomeOtherProperty { get; set; }
    }

    class TestClass
    {
		public static void Test()
		{
            var json = GetJson();
			
			Console.WriteLine("Input JSON: ");
			Console.WriteLine(json);

			Test<Values>(json);
			Test<ValuesSubclass>(json);
		}
		
        public static void Test<TValues>(string json) where TValues : Values
        {
			Console.WriteLine("\nTesting List<{0}>: ", typeof(TValues));
			
            var list = JsonConvert.DeserializeObject<List<TValues>>(json);

            var json2 = JsonConvert.SerializeObject(list, Formatting.Indented);

            Console.WriteLine("Re-serialized JSON: ");
            Console.WriteLine(json2);
			
			Assert.IsTrue(list.Count == JArray.Parse(json).Where(t => t.Type != JTokenType.Comment).Count());
        }

        static string GetJson()
        {
            var json = @"[
""2009-02-15T00:00:00Z"" /* Make sure dates work */,
""MyFirstValue""  /* if only one value */,
// If multiple values
{ ""BestValue"" : 0, ""AllValues"" : [""DefaultValue"", ""OtherValue""] },
null /* check that null works */,
""c75d06a8-a705-48ec-b6b3-9076becf20f4"" /* Make sure GUIDs work */
]";
            return json;
        }
    }

	public class Program
	{
		public static void Main()
		{
			Console.WriteLine("Environment version: " + Environment.Version);
			Console.WriteLine("Json.NET version: " + typeof(JsonSerializer).Assembly.FullName);
			Console.WriteLine();

			try
			{
				TestClass.Test();
			}
			catch (Exception ex)
			{
				Console.WriteLine("Failed with unhandled exception: ");
				Console.WriteLine(ex);
				throw;
			}
		}
	}

    public class AssertionFailedException : System.Exception
    {
        public AssertionFailedException() : base() { }

        public AssertionFailedException(string s) : base(s) { }
    }

    public static class Assert
    {
        public static void IsTrue(bool value)
        {
            IsTrue(value, "failed");
        }

        public static void IsTrue(bool value, string message)
        {
            if (value == false)
                throw new AssertionFailedException(message ?? "failed");
        }
    }