Question

My goals are:

• Display all dates in d MMM yyyy format
  • Default/existing values on first page load
  • Anything entered by the user, then round-tripped via the server
• Add class="behaviour-date-picker" to the input field so that I can show a jQuery date picker
• Build on top of the System.ComponentModel.DataAnnotations infrastructure
• Still show bad data values such as 12 Joone 2010 after a server roundtrip, with the appropriate validation error message

Here’s an example model:

public class DebugDatesStub
{
    [DataType(DataType.Date)]
    public DateTimeOffset Date { get; set; }
}

The DisplayFormat attribute doesn’t solve my scenario because it doesn’t apply to round-tripped values. (User fills in form, submits it, gets the same form back because of some server-side validation issue – date is still shown in the original format they entered instead of being reformatted.)

Answer 1

Render the field on the page with:

@Html.EditorFor(m => m.Date)

Create this code in ~\Views\Shared\EditorTemplates\Date.cshtml:

@using System.Globalization
@model DateTimeOffset?

@{
    var propertyState = ViewData.ModelState[ViewData.ModelMetadata.PropertyName];
    var displayValue =
        propertyState != null && propertyState.Errors.Any() ? propertyState.Value.AttemptedValue :
        ViewData.Model.HasValue ? string.Format("{0:d MMM yyyy}", ViewData.Model.Value) :
        string.Empty;

    ViewData.ModelState.SetModelValue(
        ViewData.ModelMetadata.PropertyName,
        new ValueProviderResult(displayValue, displayValue, CultureInfo.CurrentCulture));
}

@Html.TextBoxFor(m => m, new { @class = "behaviour-date-picker" })