Critical bug(?). Problem with Date from Model to View. Not using ISO international format.

[Bartmax]

There's a problem with the input date, the datatype and the view.
Data does't get binded to the view correctly.

Even i'm using en-us culture mvc doesn't use the correct format. I'm pretty sure the ISO international format (yyyy-MM-dd) is accepted for every culture but mvc is not using that.

Startup.cs

var cultureInfo = new CultureInfo("en-US");

app.UseRequestLocalization(
    new RequestLocalizationOptions()
    {
        DefaultRequestCulture = new RequestCulture(cultureInfo),
        SupportedUICultures = new[] { cultureInfo },
        SupportedCultures = new[] { cultureInfo }
    });

view.cshtml:

<form asp-action="Edit" enctype="multipart/form-data">
    <div class="form-horizontal">
        <div asp-validation-summary="ModelOnly" class="text-danger"></div>
        <input type="hidden" asp-for="Id" />
        <div class="form-group">
            <label asp-for="ReleaseDate" class="col-md-2 control-label"></label>
            <div class="col-md-10">
                <input asp-for="ReleaseDate" class="form-control" />
                <span asp-validation-for="ReleaseDate" class="text-danger"></span>
            </div>
        </div>

viewmodel.cs:

        [DataType(DataType.Date)]
        public DateTime? ReleaseDate { get; set; }

generated html:

<input class="form-control" type="date" id="ReleaseDate" name="ReleaseDate" value="6/2/2015" />

rendering:

Chrome warning:

The specified value "6/2/2015" does not conform to the required format, "yyyy-MM-dd".

[rynowak]

/cc @dougbu

[Eilon]

cc @javiercn

We made a change not long ago where at least certain dates are rendered in the RFC3339.

See these:

• DefaultHtmlGenerator should attempt to properly format values for <input type="date"> and <input type="time"> #4102
• [Fixes #4102] DefaultHtmlGenerator should attempt to properly format values for <input type="date"> and <input type="time"> #4250

@javiercn any thoughts on this?

[javiercn]

It seems that we don't handle nullable instances, I would say that its a bug

Mvc/src/Microsoft.AspNetCore.Mvc.TagHelpers/InputTagHelper.cs

Line 359 in 82fd17d

(typeof(DateTime) == modelExplorer.ModelType || typeof(DateTimeOffset) == modelExplorer.ModelType))

This is the value from the debugging session:

This is the point in code where we format the value:

https://github.com/aspnet/Mvc/blob/dev/src/Microsoft.AspNetCore.Mvc.ViewFeatures/ViewFeatures/ViewDataDictionary.cs#L415

This is the value from the debugging session:

You can use asp-format to workaround the issue giving it {0:yyyy-MM-dd} as the value

[Bartmax]

Problem also appears when I decorate with [DataType(DataType.Date)] even on non-nullable DateTime type.

[dougbu]

@Bartmax are you using RC1? @javiercn's fixes were done in RC2. For RC1, you need to change the default rendering. In Startup.ConfigureServices(IServiceCollection services):

services.AddViewOptions(
    options => options.HtmlHelperOptions.Html5DateRenderingMode = Html5DateRenderingMode.Rfc3339);

Note this will probably not help the DateTime? case.

[Bartmax]

I'm using RC2. I'm seeing different results from what it's supposed to experience. I will try again just to be sure.