real-world-aspnet-web-api-services

IsvalidAccount.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Web.Http.Routing;

namespace DeLoachAero.WebApi
{
    public class IsValidAccount : IHttpRouteConstraint
    {
        public static bool IsValid(string sAccount)
        {
            return (!String.IsNullOrEmpty(sAccount) &&
                sAccount.StartsWith("1234") &&
                sAccount.Length > 5);
        }

        public bool Match(HttpRequestMessage request, IHttpRoute route, string parameterName,
           IDictionary<string, object> values, HttpRouteDirection routeDirectio)
        {
            object value;

            if(values.TryGetValue(parameterName, out value) && null != value) {
                var strAccount = value as string;
                if (!String.IsNullOrEmpty(strAccount)) {
                    if (IsValid(strAccount)) { return true; }
                }
            }
            return false;
        }
    }
}

ProductController.cs

using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;

namespace TestProject3.Controllers
{
    [RoutePrefix("api/products")]
    public class ProductsController : ApiController
    {
        [JsonConverter(typeof(StringEnumConverter))]
        public enum Widgets
        {
            Bolt,
            Screw,
            Nut,
            Motor
        };

        // GET: Products/widget/xxx
        [HttpGet, Route("widget/{widget:enum(TestProject3.Controllers.ProductsController+Widgets)}")]
        public string GetProductsWithWidget(Widgets widget)
        {
            return "widget-" + widget.ToString();
        }

        [HttpGet, Route("accounts/{accountId:validAccount}")]
        public string GetValidAccout(string accountId)
        {
            return "Valid Account-"+ accountId.ToString();
        }


    }
}

WebApiConfig.cs

using DeLoachAero.WebApi;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web.Http;
using System.Web.Http.Routing;

namespace TestProject3
{
    public static class WebApiConfig
    {
        public static void Register(HttpConfiguration config)
        {

            var constraintResolver = new DefaultInlineConstraintResolver();
            constraintResolver.ConstraintMap.Add("enum", typeof(EnumerationConstraint));
            constraintResolver.ConstraintMap.Add("validAccount", typeof(IsValidAccount));
            config.MapHttpAttributeRoutes(constraintResolver);
        }
    }
}