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 Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

​

// https://stackoverflow.com/questions/46611888/json-net-select-all-objects

​

    public static partial class JTokenExtensions

    {

        public static JObject [] FilterObjects<T>(this JObject root, string someProp, T someValue)

        {

            var comparer = new JTokenEqualityComparer();

            var someValueToken = JToken.FromObject(someValue);

            var objs = root.DescendantsAndSelf()

                .OfType<JObject>()

                .Where(t => comparer.Equals(t[someProp], someValueToken))

                .ToArray();

​

            return objs;

        }

    }

​

    public static partial class JTokenExtensions

    {

        public static bool IsNull(this JToken token)

        {

            return token == null || token.Type == JTokenType.Null;

        }

​

        public static JObject[] FilterObjectsSimple<T>(this JObject root, string someProp, T someValue)

        {

            var comparer = EqualityComparer<T>.Default;

            var objs = root.DescendantsAndSelf()

                .OfType<JObject>()

                .Where(t => { var v = t[someProp]; return v != null && (someValue == null ? v.IsNull() : comparer.Equals(v.ToObject<T>(), someValue)); })

                .ToArray();

​

            return objs;

        }

    }

​

    class TestClass

    {

        public static void Test()

        {

            var jsonString = GetJson();

​

            var root = JObject.Parse(jsonString);

​

            var allObjs = root.DescendantsAndSelf()

                .OfType<JObject>()

                .ToArray();

​

            Console.WriteLine("\nCount of all objects: {0}", allObjs.Length);

            Assert.IsTrue(allObjs.Length == 7);

​

            TestFilterObjects(jsonString, "id", "3", 2);

​

            TestFilterObjectsSimple(jsonString, "id", "3", 2);

​

            try

            {

                TestSelectTokens(jsonString);

            }

            catch (AssertionFailedException ex)

            {

                Console.WriteLine("Searching using JSONPath failed: " + ex.Message);

            }

​

            Console.WriteLine("\nDone");

        }

​

        static void TestFilterObjects<T>(string jsonString, string someProp, T someValue, int expectedCount)

        {

            var root = JObject.Parse(jsonString);

​

            var filteredObjs = root.FilterObjects(someProp, someValue);

​

            Console.WriteLine("\nAll objects with {0} == {1}:", someProp, someValue);

            Console.WriteLine(JsonConvert.SerializeObject(filteredObjs, Formatting.Indented));

​

            Assert.IsTrue(filteredObjs.Length == expectedCount);

        }

​

        static void TestFilterObjectsSimple<T>(string jsonString, string someProp, T someValue, int expectedCount)

        {

            var root = JObject.Parse(jsonString);

​

            var filteredObjs = root.FilterObjectsSimple(someProp, someValue);

​

            Console.WriteLine("\nAll objects with {0} == {1}:", someProp, someValue);

            Console.WriteLine(JsonConvert.SerializeObject(filteredObjs, Formatting.Indented));

​

            Assert.IsTrue(filteredObjs.Length == expectedCount);

        }

​

        static void TestSelectTokens(string jsonString)

        {

            var root = JObject.Parse(jsonString);

​

            var someProp = "id";

            var someValue = "3";

            var filterString = string.Format(@"..*[?(@.{0} == '{1}')]", someProp, someValue);

            var filteredObjs = root.SelectTokens(filterString).ToArray();

​

            Console.WriteLine("\nTesting query string \"{0}\", all objects with {1} == {2}:", filterString, someProp, someValue);

            Console.WriteLine(JsonConvert.SerializeObject(filteredObjs, Formatting.Indented));

​

            Assert.IsTrue(filteredObjs.Length == 2, "filteredObjs.Length != 2");

        }

​

        static string GetJson()

        {

            var json = @"{

  ""someCar"" : {

    ""id"" : ""3"",

    ""model"" : ""M7"",

    ""engine"" : ""FI V8"",

  },

  ""name"" : ""carparkone"",

  ""id"" : ""1"",

  ""cars"" : [

    {

      ""id"" : ""1"",

      ""model"" : ""s60"",

      ""engine"" : ""i5"",

    },

    {

      ""id"" : ""2"",

      ""model"" : ""m3"",

      ""engine"" : ""FI V6"",

    },

    {

      ""id"" : ""3"",

      ""model"" : ""M7"",

      ""engine"" : ""FI V8"",

    },

    {

      ""model"" : ""M7 With No Id"",

      ""engine"" : ""FI V8"",

    },

    {

      ""id"" : null,

      ""model"" : ""M7 With Null Id"",

      ""engine"" : ""FI V8"",

    }

  ]

}";

            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");

        }

    }

​