Steps to reproduce:

1. Open the Edit in Telerik REPL link from the demo page for DropDownList - Grouping.
2. Add Filterable="true" to TelerikDropDownList.
3. Run.
4. Open the dropdown.
5. Type in for instance the last item of the list "Röd Kaviar", that belongs to the category "Seafood".

Expected: the group name should change to "Seafood".

Actual: the group name is still "Beverages".

Currently, a TextField value of empty string will produce a blank item in the dropdown.

On the other hand, a null TextField value will produce the fully qualified class name.

Here are possible workarounds: https://blazorrepl.telerik.com/myOlFpFb1465jW8E07

TlerikDropDownList keyboard navigation works differently from native html select.

In case we have a list with many similar options, for example:
011
021
211
....
In this case with native html select I can type 02 to select 021, but with TlerikDropDownList this would select 211.

If you type swiftly multiple printable characters, the DropDownList keyboard navigation will react only to the first character.

At the moment, typing with the keyboard focuses the first item that starts with the last letter you pressed. To focus the next one you should either use Down Arrow, or type the same letter again.

I would like it to behave like the regular <select> or like a combo box with filtering - typing characters quickly should highlight the item that begins with all those characters, instead of using only the first letter.

=== 

Admit edit: some keywords for better findability: DropDownList keyboard search filter accessibility

Hi!

When i use combination of LINQ inside TelerikDropDownLists Data attribute and TelerikGrid 's GridEditMode.Popup mode, i get weird behavior when i try to select an item from TelerikDropDownLists - everything freezes. Please check the solution. Everything works fine if i don't use LINQ or GridEditMode.Popup mode.

Thank you!

Using DropDownList with Filter enabled will lost track of Focus when an item from dropdown is selected or tabbing away from filter input.

Steps to reproduce:

1. Open a DropDownList with filter enabled
2. Press TAB

Expected Behavior:

Focus in the next focusable element

Actual Behavior:

Focus is lost, and will go to the browser buttons

It is possible to reproduce in the demos:

https://demos.telerik.com/blazor-ui/dropdownlist/filtering

The DropDownList component is too basic to be used in complex environments. In the real world, no one is binding DropDownLists to List<string>, they are binding to complex datatypes, and the ability to do so has been present in MVC apps for a long time.

Given the following code, it is possible to bind to a List<object>, and two-way bind to the object that was selected.

	<select @onchange="@OnChangedAsync">
		<option></option>
		@if (DataSource != null)
		{
			@foreach (var item in DataSource)
			{
				<option @key="item" value="@optionValueFunc(item)" selected="@(item.Equals(SelectedItem))">@optionTextFunc(item)</option>
			}
		}
	</select>

	#region Private Members

	private Func<TSource, object> optionTextFunc;
	private Func<TSource, object> optionValueFunc;
	private TSource selectedItem = default(TSource);

	#endregion

        #region Public Parameters

	/// <summary>
	/// A List of objects to bind against.
	/// </summary>
	[Parameter]
	public IList<TSource> DataSource { get; set; } = new List<TSource>();

	/// <summary>
        /// A lambda expression referencing the property containing the text to display to the end user. Example: @(c => c.DisplayName)
        /// </summary>
        [Parameter]
        public Expression<Func<TSource, object>> OptionText { get; set; }

	/// <summary>
        /// A lambda expression referencing the property containing the value for this object, usually an identifier. Example: @(c => c.Id)
        /// </summary>
        [Parameter]
        public Expression<Func<TSource, object>> OptionValue { get; set; }

	/// <summary>
        /// The item from the <see cref="DataSource" /> that has been selected.
        /// </summary>
        [Parameter]
        public TSource SelectedItem { get; set; }

	/// <summary>
	/// The callback event required for two-way binding.
	/// </summary>
	[Parameter]
        public EventCallback<TSource> SelectedItemChanged { get; set; }

        #endregion

	private async Task OnChangedAsync(ChangeEventArgs changeEventArgs)
        {
            await UpdateSelection(DataSource.FirstOrDefault(c => optionValueFunc(c).ToString() == changeEventArgs.Value.ToString()));
        }

	private async Task UpdateSelection(TSource item)
        {
            selectedItem = item;
            await SelectedItemChanged.InvokeAsync(selectedItem);
        }

	protected override async Task OnInitializedAsync()
	{
            if (optionTextFunc == null && OptionText != null)
            {
                optionTextFunc = OptionText.Compile();
            }
            if (optionValueFunc == null && OptionText != null)
            {
                optionValueFunc = OptionValue.Compile();
            }
            await Task.CompletedTask;          
        }

Would really appreciate it if you would consider adding this to the next release.

When using the grouped DropDownList and performing a search for a specific element, the DropDownList incorrectly displays the initially shown group instead of the group containing the searched element.

The DropDownList remains open after tabbing and does not fire. It also won't fire OnBlur and OnChange in this case. The problem occurs only if the component was opened by clicking exactly on its arrow.

Here is a test page: https://blazorrepl.telerik.com/cxEfFVPq042owTt616

The workaround is to wrap the component in a <span> that handles @onfocusout and closes the component programmatically: https://blazorrepl.telerik.com/cnafPCYL21aT3fpD05

Hi,

Is it possible to implement search/look-ahead in the current version of the DropDown component? If not, will you be adding this feature soon?

Thank you.

Ben

I need to be able to allow our users to tab into the dropdownlist control and open it with enter (similar to standard HTML select).

Here is also a sample from the W3 documentation to compare against: DropDownList keyboard support.

Right now when a DropDownList has PopupHeight="Auto" the popup gets the height necesaary to display its items properly.

But when there are many items the popup also displays all items without a vertical scrollbar (maybe over the entire page and beyond), which is not good.

My suggestion would be to add a property for specifyig a "MaxPopupHeight" to limit the growth of the popup.

Also if "PopupHeight" is not specified it should take "Auto" as the default value instead of a static height in px, instead give the new "MaxPopupHeight" a limiting default value.

***Admin Edit***

Released in 3.0.0 through PopupSettings tag: https://docs.telerik.com/blazor-ui/upgrade/breaking-changes/3-0-0#popup-settings

***Admin Edit***