#region License // Copyright (c) 2007 James Newton-King // // Permission is hereby granted, free of charge, to any person // obtaining a copy of this software and associated documentation // files (the "Software"), to deal in the Software without // restriction, including without limitation the rights to use, // copy, modify, merge, publish, distribute, sublicense, and/or sell // copies of the Software, and to permit persons to whom the // Software is furnished to do so, subject to the following // conditions: // // The above copyright notice and this permission notice shall be // included in all copies or substantial portions of the Software. // // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES // OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT // HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, // WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING // FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR // OTHER DEALINGS IN THE SOFTWARE. #endregion using Newtonsoft.Json.Linq; using System; using System.Collections.Generic; using System.Text; #if DNXCORE50 using Xunit; using Test = Xunit.FactAttribute; using Assert = Newtonsoft.Json.Tests.XUnitAssert; #else using NUnit.Framework; #endif #if NET20 using Newtonsoft.Json.Utilities.LinqBridge; #else using System.Linq; #endif namespace Newtonsoft.Json.Tests.Documentation.Samples.Serializer { [TestFixture] public class CustomJsonConverter : TestFixtureBase { #region Types public class KeysJsonConverter : JsonConverter { private readonly Type[] _types; public KeysJsonConverter(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; IList propertyNames = o.Properties().Select(p => p.Name).ToList(); o.AddFirst(new JProperty("Keys", new JArray(propertyNames))); o.WriteTo(writer); } } 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 IList Roles { get; set; } } #endregion [Test] public void Example() { #region Usage Employee employee = new Employee { FirstName = "James", LastName = "Newton-King", Roles = new List { "Admin" } }; string json = JsonConvert.SerializeObject(employee, Formatting.Indented, new KeysJsonConverter(typeof(Employee))); Console.WriteLine(json); // { // "Keys": [ // "FirstName", // "LastName", // "Roles" // ], // "FirstName": "James", // "LastName": "Newton-King", // "Roles": [ // "Admin" // ] // } Employee newEmployee = JsonConvert.DeserializeObject(json, new KeysJsonConverter(typeof(Employee))); Console.WriteLine(newEmployee.FirstName); // James #endregion Assert.AreEqual("James", newEmployee.FirstName); } } }