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 System.Reflection;

​

​

using Newtonsoft.Json;

using Newtonsoft.Json.Linq;

using Newtonsoft.Json.Converters;

using Newtonsoft.Json.Serialization;    

​

// https://stackoverflow.com/questions/47164280/how-to-use-asp-net-core-modelmetadata-attribute#comment81278862_47164280

​

namespace Microsoft.AspNetCore.Mvc

{

    [AttributeUsage(AttributeTargets.Class, AllowMultiple = false, Inherited = true)]

    public class ModelMetadataTypeAttribute : Attribute

    {

        public ModelMetadataTypeAttribute(Type type)

        {

            if (type == null)

            {

                throw new ArgumentNullException();

            }

​

            MetadataType = type;

        }

​

        public Type MetadataType { get; private set;  }

    }

}

​

namespace Question47164280

{

    using Microsoft.AspNetCore.Mvc;

​

        public class Entity<T>

        {

            public T Id { get; set; }

​

            public string Name { get; set; }

        }

​

        [Microsoft.AspNetCore.Mvc.ModelMetadataType(typeof(LegalEntityMeta))]

        public class LegalEntity : Entity<long>

        {

            public string LegalData { get; set; }

        }

​

        public class LegalEntityMeta

        {

            [JsonProperty(PropertyName = "LegalEntityId")]

            public long Id { get; set; }

​

            [JsonProperty(PropertyName = "LegalEntityName")]

            public string Name { get; set; }

​

            [JsonProperty(PropertyName = "LegalEntityDataValue")]

            public string LegalData { get; set; }

        }

​

        class TestClass

        {

            public static void Test()

            {

                var entity = new LegalEntity

                {

                    Id = 101010101,

                    Name = "my name",

                };

​

                var settings = new JsonSerializerSettings

                {

                    ContractResolver = new ModelMetadataTypeAttributeContractResolver { /* NamingStrategy = new CamelCaseNamingStrategy() */ },

                };

​

                var json = JsonConvert.SerializeObject(entity, Formatting.Indented, settings);

                Console.WriteLine(json);

            }

        }

​

        public class ModelMetadataTypeAttributeContractResolver : DefaultContractResolver

        {

            public ModelMetadataTypeAttributeContractResolver()

            {

                // Default from https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNetCore.Mvc.Formatters.Json/JsonSerializerSettingsProvider.cs

                //NamingStrategy = new CamelCaseNamingStrategy();

            }

​

            const string ModelMetadataTypeAttributeName = "Microsoft.AspNetCore.Mvc.ModelMetadataTypeAttribute";

            const string ModelMetadataTypeAttributeProperty = "MetadataType";

​

            protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)

            {

                var properties = base.CreateProperties(type, memberSerialization);

​

                var propertyOverrides = GetModelMetadataTypes(type)

                    .SelectMany(t => t.GetProperties())

                    .ToLookup(p => p.Name, p => p);

​

                foreach (var property in properties)

                {

                    var metaProperty = propertyOverrides[property.UnderlyingName].FirstOrDefault();

                    if (metaProperty != null)

                    {

                        var jsonPropertyAttribute = metaProperty.GetCustomAttributes<JsonPropertyAttribute>().FirstOrDefault();

                        if (jsonPropertyAttribute != null)

                        {

                            property.PropertyName = jsonPropertyAttribute.PropertyName;

                            // Copy other attributes over if desired.

                        }

                    }

                }

​

                return properties;

            }

​

            static Type GetModelMetadataType(Attribute attribute)

            {

                var type = attribute.GetType();

                if (type.FullName == ModelMetadataTypeAttributeName)

                {

                    var property = type.GetProperty(ModelMetadataTypeAttributeProperty);

                    if (property != null && property.CanRead)

                    {

                        return property.GetValue(attribute, null) as Type;

                    }

                }

                return null;

            }

​

            static Type[] GetModelMetadataTypes(Type type)

            {

                var query = from t in type.BaseTypesAndSelf()

                            from a in t.GetCustomAttributes(false).Cast<System.Attribute>()

                            let metaType = GetModelMetadataType(a)

                            where metaType != null

                            select metaType;

                return query.ToArray();

            }

        }

​

        public static partial class TypeExtensions

        {

            public static IEnumerable<Type> BaseTypesAndSelf(this Type type)

            {

                while (type != null)

                {

                    yield return type;

                    type = type.BaseType;

                }

            }

        }

​

    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");

        }

    }

}

​