iot/projects/Infrastructure/Web/AjaxSelectAttribute.cs

using Infrastructure.Web.Mvc;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Mvc.ModelBinding.Validation;
using Microsoft.AspNetCore.Mvc.Routing;
using Microsoft.AspNetCore.Routing;
using Microsoft.Extensions.DependencyInjection;
using System.Reflection;

namespace System.ComponentModel.DataAnnotations
{
    public class AjaxSelectAttribute : UIHintAttribute, IClientModelValidator
    {
        public string Action { get; }
        public string Controller { get; }
        public string Area { get; }
        protected RouteValueDictionary RouteData { get; } = new RouteValueDictionary();
        public AjaxSelectAttribute(string action, string controller, string area = null) : base("AjaxSelect")
        {
            this.Action = action;
            this.Controller = controller;
            this.Area = area;
        }

        public void AddValidation(ClientModelValidationContext context)
        {
            var key = "data-ajax-url";
            var value = GetUrl(context);
            var attributes = context.Attributes;
            if (!attributes.ContainsKey(key))
            {
                attributes.Add(key, value);
            }
        }

        private string GetUrl(ClientModelValidationContext context)
        {
            var scope = (context.ActionContext.ActionDescriptor as ControllerActionDescriptor)
                .ControllerTypeInfo
                .GetCustomAttribute<ControllerScopeAttribute>();
            var url = context.ActionContext.HttpContext.RequestServices.GetRequiredService<IUrlHelperFactory>()
                .GetUrlHelper(context.ActionContext).Action(Action, Controller, new { area = Area, range = scope?.Scope });
            return url;
        }
    }
}