Custom date input format in .net mvc3 entity framework webapp?

I have the requirement that users should be allowed to enter dates in the format "yymmdd", 6 digits in total in a textfield.

The form is posted via unobtrusive ajax to a mvc3 controller/action which persists this to a mysql database via Entity Framework 4.1. Unfortionently it saves the date as a null if I enter the date in the desired "yymmdd" format.

My question is how do I use a custom date format, retain client- and serverside validation and successfully persist this date into the database. I'm happy to use a regexp for the validation but need help to parse the custom date format.

The date in the modelis specified as

public class CustomDate {
  [DisplayFormat(ApplyFormatInEditMode = true, DataFormatString = "{0:yyMMdd}")]
  //[RegularExpression(@"^[0-9]{6}$")]
  public DateTime? Something { get; set; } 
}

The action backing the form have the following signature.

public JsonResult NewClaim(CustomDate d) {
db.CustomDate.Add.(d);
db.SaveChan开发者_运维问答ges();
}

You could write a custom model binder for the server side validation:

public class DateModelBinder : DefaultModelBinder
{
    public override object BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext)
    {
        var value = bindingContext.ValueProvider.GetValue(bindingContext.ModelName);
        if (value == null) 
        {
            return null;
        }

        var format = bindingContext.ModelMetadata.EditFormatString ?? string.Empty;
        format = format.Replace("{0:", string.Empty).Replace("}", string.Empty);
        if (!string.IsNullOrEmpty(format))
        {
            DateTime date;
            if (DateTime.TryParseExact(value.AttemptedValue, format, CultureInfo.InvariantCulture, DateTimeStyles.None, out date))
            {
                return date;
            }
        }
        return base.BindModel(controllerContext, bindingContext);
    }
}

which you would register in Application_Start:

ModelBinders.Binders.Add(typeof(DateTime?), new DateModelBinder());

For the client side validation there are different techniques that could be employed. For example you could handle it manually:

<script>
    $.validator.addMethod('myDate', function (value, element) {
        // TODO: validate if the value corresponds to the required format
        // and return true or false based on it
        return false;
    }, 'Please enter a date in the format yyMMdd');

    $(function () {
        // Attach the myDate custom rule to the #Something element
        $('#Something').rules('add', 'myDate');
    });
</script>