iot/labs/CSharpObjectJsonSchema/Controllers/HomeController.cs

using CSharpObjectJsonSchema.Models;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.ModelBinding;
using Microsoft.AspNetCore.Mvc.ModelBinding.Metadata;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Logging;
using Newtonsoft.Json;
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
using System.Diagnostics;
using System.Dynamic;
using System.Linq;
using System.Reflection;

namespace CSharpObjectJsonSchema.Controllers
{
    public class HomeController : Controller
    {
        private readonly ILogger<HomeController> _logger;

        public HomeController(ILogger<HomeController> logger)
        {
            _logger = logger;
        }

        public string Index()
        {
            var metadata = this.HttpContext.RequestServices.GetRequiredService<IModelMetadataProvider>().GetMetadataForType(new TestModel().GetType()) as DefaultModelMetadata;
            var json = CreateJson(metadata);
            return JsonConvert.SerializeObject(json, Formatting.Indented);
        }

        private object CreateJson(DefaultModelMetadata metadata)
        {
            try
            {
                dynamic json = new ExpandoObject();
                var dictionary = (IDictionary<string, object>)json;
                //type
                if (metadata.IsComplexType && metadata.IsCollectionType)
                {
                    json.type = "array";
                    json.items = new { type = metadata.ModelType.GenericTypeArguments[0].Name };
                }
                else if (metadata.IsNullableValueType)
                {
                    json.type = metadata.ModelType.GenericTypeArguments[0].Name;
                }
                else
                {
                    json.type = metadata.ModelType.Name;
                }
                if (!metadata.IsComplexType && !metadata.IsNullableValueType && metadata.ModelType != typeof(string))
                {
                    json.required = true;
                }
                if (metadata.DisplayName != null)
                {
                    json.title = metadata.DisplayName;
                }
                foreach (var attribute in metadata.Attributes.Attributes)
                {
                    if (attribute is DescriptionAttribute descriptionAttribute)
                    {
                        json.description = descriptionAttribute.Description;
                    }
                    else if (attribute is RegularExpressionAttribute regularExpressionAttribute)
                    {
                        json.pattern = regularExpressionAttribute.Pattern;
                    }
                    else if (attribute is RequiredAttribute requiredAttribute)
                    {
                        json.required = true;
                    }
                    //
                    else if (attribute is CompareAttribute compareAttribute)
                    {
                        json.compare = compareAttribute.OtherProperty;
                    }
                    else if (attribute is RemoteAttribute remoteAttribute)
                    {
                        var routeData = attribute.GetType().GetProperty("RouteData", BindingFlags.NonPublic | BindingFlags.Instance).GetValue(remoteAttribute) as RouteValueDictionary;
                        json.remote = new
                        {
                            url = Url.Action(routeData["action"].ToString(), routeData["controller"].ToString(), new { Area = routeData["area"].ToString() }),
                            remoteAttribute.AdditionalFields,
                            //remoteAttribute.
                        };
                    }
                }
                dynamic properties = new ExpandoObject();
                var propertiesDictionary = (IDictionary<string, object>)properties;
                if (metadata.IsComplexType && !metadata.IsCollectionType && metadata.Properties.Any())
                {
                    foreach (var item in metadata.Properties)
                    {
                        propertiesDictionary[item.PropertyName] = CreateJson(item as DefaultModelMetadata);
                    }
                    json.properties = properties;
                }
                return json;
            }
            catch (Exception ex)
            {
                return null;
            }
            //Console.WriteLine(metadata.DataTypeName);
        }

        public IActionResult Privacy()
        {
            return View();
        }

        [ResponseCache(Duration = 0, Location = ResponseCacheLocation.None, NoStore = true)]
        public IActionResult Error()
        {
            return View(new ErrorViewModel { RequestId = Activity.Current?.Id ?? HttpContext.TraceIdentifier });
        }
    }
}