Bug report

The DropDownTree's refresh API method re-renders only the noDataTemplate and the footerTemplate. The nodes are not re-rendered.

Reproduction of the problem

Current behavior

Only the noDataTemplate and the footerTemplate are re-rendered.

Expected/desired behavior

The method should also re-render the nodes, similarly to the DropDownList's refresh method, which re-renders its items.

Environment

• Kendo UI version: 2021.1.330
• jQuery version: x.y
• Browser: [all]

Hi
I have a problem with the DropDownTree component.
From a remote data source type json I am getting a tree with two levels of data but it only shows the first level.

Code:

$("#dropdowntree").kendoDropDownTree({
	dataSource: {
		transport: {
			read: {
				url: "/api/getData",
				type: "POST",
				dataType: "json",
				contentType: "application/json; charset=utf-8"
			}
		}
	},
	checkboxes: true
});

Response:

[
	{
		text: "Furniture", expanded: true, items: [
			{ text: "Tables & Chairs" },
			{ text: "Sofas" },
			{ text: "Occasional Furniture" }
		]
	},
	{
		text: "Decor", items: [
			{ text: "Bed Linen" },
			{ text: "Curtains & Blinds" },
			{ text: "Carpets" }
		]
	}
]

$("#dropdowntree").kendoDropDownTree({
	dataSource: {
		data: [
			{
				text: "Furniture", expanded: true, items: [
					{ text: "Tables & Chairs" },
					{ text: "Sofas" },
					{ text: "Occasional Furniture" }
				]
			},
			{
				text: "Decor", items: [
					{ text: "Bed Linen" },
					{ text: "Curtains & Blinds" },
					{ text: "Carpets" }
				]
			}
		]
	},
	checkboxes: true
});

Using setDataSource method on a working DropDownTree, with same initial settings leads to not working clea button and not expanding a collapsed node. 

Dojo: https://dojo.telerik.com/uLUNudEJ 

Steps (clear button):

1. Open dojo and check that everything works correctly

2. Click reload button (calls setDataSource)

3. Clear all button does not work and cannot deselect the item from the tag's clear button.

Steps (expand):

1. Open dojo and open popup to see everything expands as expected

2. Click reload

3. Open popup

4. The last (initially collapsed) node cannot be expanded.

Bug report

If the DropDownTree is configured without checkboxes (single selection), the X button shouldn't be present.

Reproduction of the problem

1. Open this demo - https://demos.telerik.com/kendo-ui/dropdowntree/index
2. Select an item from the DropDownTree

Current behavior

The clear button appears

Expected/desired behavior

The clear button shouldn't be present.

Environment

• Kendo UI version: 2022.3.1109
• Browser: [all]