Kendo DropDownList bound to Model in Razor Pages scenario does not render data attributes

[martintabakov]

Bug report

The data attributes are not rendered for the DropDownlist when bound to Model in Razor Pages.

Reproduction of the problem

View:

@page
@model TelerikAspNetCoreApp12.Pages.IndexModel

<form>
    @(Html.Kendo().DropDownList()
            .Name("fabric")
            .OptionLabel("Select...")
            .DataTextField("Text")
            .DataValueField("Value")
            .BindTo(Model.Data)
            .Filter("contains")
    )
    <input type="submit" />
</form>

Back end:

namespace TelerikAspNetCoreApp12.Pages
{
    public class IndexModel : Microsoft.AspNetCore.Mvc.RazorPages.PageModel
    {
        public List<TestModel> Data { get; set; } = new List<TestModel>();

        public void OnGet()
        {
            for (int i = 1; i <= 100; i++)
            {
                Data.Add(new TestModel() { Text = "product" + i, Value = i.ToString() });
            }
        }
    }
}

Model:

namespace TelerikAspNetCoreApp12.Models
{
    public class TestModel
    {
        [Required(ErrorMessage = "Please select")]

        public string Text { get; set; }

        public string Value { get; set; }
    }
}

Inspect the input field for the DropDownList. It does not have data-val and data-val-required attributes.

Current behavior

The data attributes are not being rendered.

Expected/desired behavior

The data attributes should be rendered.

Environment

• Kendo UI version: 2019.2.619
• jQuery version: x.y
• Browser: [all]

TelerikAspNetCoreApp3.zip

[veselints]

Closing the issue as it was caused by improper configuration of the project. Below you will find a working project with the latest Kendo version:

InRazorPagesBindTo.zip

[paulterinho]

Hi @veselints Could you elaborate on how the configuration was improper? I'm looking at a similar issue.

[veselints]

@paulito-bandito, in the initial project sample the page model does not contain any field that is marked as [Required]. The [Required] attribute is used instead on a property of the model that is used to populate the DropDownList source collection:

[Required(ErrorMessage = "Please select")]
public string Text { get; set; }

Moreover, the DropDownList helper does not point to any property of the model.

If you review the correct sample that I have uploaded in my previous reply:

• The page model contains a [BindProperty] with [Required] attribute:

[Required]
[BindProperty]
public string KendoDropDownValue { get; set; }

• The DropDownList helper uses its strongly typed version to define value binding with that model field:

@(Html.Kendo().DropDownListFor(m => m.KendoDropDownValue)

[paulterinho]

Ahhhh, it's clear now. Thanks a alot for the clarification. That helps a ton!