Question

I have a MVC 3 project that uses Entity Framework. I can successfully update entities like this:

[HttpPost]
publiv RedirectResult Update(MyEntity entity)
{
    if(ModelState.IsValid)
    {
        this.entityRepository.Update(entity);
        return RedirectResult(".../Admin");
    }
    return RedirectResult(".../UnssuccessfullOperation");
}

Now the problem arised when I added DateTime property to my entities. If I do not add the @Html.HiddenFor for my DateTime property the date of my entity is 01.01.0001 (or DateTime.Min), which obviously cannot be saved to the database. If I add the hidden input the date is rendered but on update my ModelState is not valid and I guess this is due to the fact that the datetime is passed as a string.

Now there is one solution, but it seems a little strange – to not render Html.Hidden in the view and to use the datetime from the entityRepository like this:

entity.DateSomething = this.entityRepository.GetSingle(entity.ID).DateSomething;

but it does not seem very correct. Are there any other better options in that case?

Answer 1

If I add the hidden input the date is rendered but on update my
ModelState is not valid and I guess this is due to the fact that the
datetime is passed as a string.

No, I suspect that it’s due to the culture setting in your application and the datetime format used in the hidden field. They probably don’t match.

Take a look at the following blog post which covers the different issues that arise when parsing dates and how the format will depend on whether you are doing a GET or POST request and also a possibility to write a custom model binder to use a fixed format for dates.