DataAnnotation for Required property

Question

First it works, but today it failed!

This is how I define the date property:

[Display(Name = "Date")] [Required(ErrorMessage = "Date of Submission is required.")]         [DisplayFormat(DataFormatString = "{0:d}", ApplyFormatInEditMode = true)] [DataType(DataType.Date)] public DateTime TripDate { get; set; } 

It has been working in the past. But today, when I call the same ApiController action:

[HttpPost] public HttpResponseMessage SaveNewReport(TripLeaderReportInputModel model) 

The Firebug reports:

ExceptionMessage:  "Property 'TripDate' on type 'Whitewater.ViewModels.Report.TripLeaderReportInputModel'  is invalid. Value-typed properties marked as [Required] must also be marked with [DataMember(IsRequired=true)] to be recognized as required. Consider attributing the  declaring type with [DataContract] and the property with [DataMember(IsRequired=true)]."  ExceptionType  "System.InvalidOperationException" 

What happened? Isn't those [DataContract] for WCF? I am using the REST WebAPI in MVC4!

Can anyone help? please?

---update---

There are some similar links I have found.

MvC 4.0 RTM broke us and we don't know how to fix it RSS

--- update again ---

Here is the HTTP Response Header:

Cache-Control   no-cache Connection  Close Content-Length  1846 Content-Type    application/json; charset=utf-8 Date            Thu, 06 Sep 2012 17:48:15 GMT Expires         -1 Pragma          no-cache Server          ASP.NET Development Server/10.0.0.0 X-AspNet-Version    4.0.30319 

Request Header:

Accept          */* Accept-Encoding gzip, deflate Accept-Language en-us,en;q=0.5 Cache-Control   no-cache Connection          keep-alive Content-Length  380 Content-Type    application/x-www-form-urlencoded; charset=UTF-8 Cookie          .ASPXAUTH=1FF35BD017B199BE629A2408B2A3DFCD4625F9E75D0C58BBD0D128D18FFDB8DA3CDCB484C80176A74C79BB001A20201C6FB9B566FEE09B1CF1D8EA128A67FCA6ABCE53BB7D80B634A407F9CE2BE436BDE3DCDC2C3E33AAA2B4670A0F04DAD13A57A7ABF600FA80C417B67C53BE3F4D0EACE5EB125BD832037E392D4ED4242CF6 DNT                 1 Host            localhost:39019 Pragma          no-cache Referer         http://localhost:39019/Report/TripLeader User-Agent          Mozilla/5.0 (Windows NT 6.1; WOW64; rv:15.0) Gecko/20100101 Firefox/15.0 X-Requested-With    XMLHttpRequest 

--- update ---

I have found out a makeshift solution. See answer below. If anyone understand why it works or has better solutions, please post your answers. Thank you.

Answer 1

Okay. Though I have not complete understood this thing. A workaround is found.

In Global.asax:

GlobalConfiguration.Configuration.Services.RemoveAll(     typeof(System.Web.Http.Validation.ModelValidatorProvider),     v => v is InvalidModelValidatorProvider); 

I found it in the Issue Tracker in aspnetwebstack. Here is the link to the page:

Overly aggressive validation for applying [DataMember(IsRequired=true)] to required properties with value types

If anyone can tell us why it is like this, please post your insight as answers. Thank you.

Answer 2

I have added a ModelValidationFilterAttribute and made it work:

public class ModelValidationFilterAttribute : ActionFilterAttribute {     public override void OnActionExecuting(HttpActionContext actionContext)     {         if (!actionContext.ModelState.IsValid)         {             // Return the validation errors in the response body.             var errors = new Dictionary<string, IEnumerable<string>>();             //string key;             foreach (KeyValuePair<string, ModelState> keyValue in actionContext.ModelState)             {                 //key = keyValue.Key.Substring(keyValue.Key.IndexOf('.') + 1);                 errors[keyValue.Key] = keyValue.Value.Errors.Select(e => e.ErrorMessage);             }             //var errors = actionContext.ModelState             //    .Where(e => e.Value.Errors.Count > 0)             //    .Select(e => new Error             //    {             //        Name = e.Key,             //        Message = e.Value.Errors.First().ErrorMessage             //    }).ToArray();              actionContext.Response =                 actionContext.Request.CreateResponse(HttpStatusCode.BadRequest, errors);         }     } } 

You can either add [ModelValidation] filter on the actions. Or add it into Global.asax.cs:

GlobalConfiguration.Configuration.Services.RemoveAll( typeof(System.Web.Http.Validation.ModelValidatorProvider), v => v is InvalidModelValidatorProvider); 

In this way, I continue to use the original data annotation.

Reference