Enhancement 

Add support for setting ClientHeaderTemplate as a function in Html Helper Grid

Current behavior
ClientHeaderTemplate can be set only as a string

Expected/desired behavior
ClientHeaderTemplate shall allow executing a function 

Environment
Kendo UI version: all
Browser: all

When certain options of the editable Window are set through configuration, they are not being serialized correctly:

MinWidth
MinHeight
Events (Open, Close, etc.)

### Bug report

The attributes set through the "HtmlAttributes", "ContentHtmlAttributes", and "LinkHtmlAttributes"methods are not applied to the TreeView items.

### Reproduction of the problem

1. Create a TreeView and set attributes by using the "HtmlAttributes", "ContentHtmlAttributes", "LinkHtmlAttributes"methods:

@(Html.Kendo().TreeView()
    .Name("treeview-kendo2")
    .Items(treeview =>
    {
        treeview.Add().Text("My Documents")
        .SpriteCssClasses("k-icon k-i-globe")
        .Expanded(true)
        .Url("/")
        .HtmlAttributes(new { @class = "fairydust1" })
        .ContentHtmlAttributes(new { data_navigate = "navigate_content", @class = "trigger", title = "content_title" })
        .LinkHtmlAttributes(new { data_navigate = "navigate_link", @class = "trigger", title = "content_link" });
    })
)

2. Run the page and inspect the TreeView item.

### Expected/desired behavior

The attributes are serialized and rendered.

### Environment

* **Kendo UI version: 2021.2.616
* **jQuery version: 1.12.4
* **Browser: [all]

### Bug report

When the Virtualization of the MultiColumnComboBox is enabled, the table headers and rows are not aligned correctly.

### Reproduction of the problem

A Dojo sample for reproduction: https://dojo.telerik.com/ORalaWoq

The tables and rows are aligned as expected when using version 2021 R3 SP2 (2021.3.1207).

A temporary workaround:

<style>
    .k-table-list .k-table-group-row, .k-table-list .k-table-row {
        display: inline-flex;
    }
</style>

### Expected/desired behavior

The headers and rows should be aligned correctly when the Virtualization is enabled.

### Environment

* **Kendo UI version: 2022.1.412
* **jQuery version: 1.12.4
* **Browser: [all]

When both UI for ASP.NET MVC and UI for ASP.NET Core Visual Studio extensions are installed and only UI for ASP.NET Core project is loaded, the notification for new version is shown for UI for ASP.NET MVC.

Bug report

If a ListItem element contains a margin-left style, the user can not delete the bulleted item.

Reproduction of the problem

1. Go to this Progress Kendo UI Dojo.
2. Using case 1 in the code, attempt to delete a bulleted item using the backspace.
3. Using case 2, only the last bulleted item is using margin-left and will not be able to delete.

Here is a screencast of Case 1 in action.

Expected/desired behavior

The bulleted item should be deleted when the user presses backspace.

Environment

• Kendo UI version: 2020.3.1118
• Browser: all

Bug report
Remote Validator Not Blocking Form Submission

Reproduction of the problem

Project attached

Expected/desired behavior
Form submission shall trigger after the validation has completed

Environment
Kendo UI version: [all]
Browser: [all]

Bug report

Problem with ToTreeDataSourceResult method when filtering on root and child level.

Also applying filtering causes a significant slowdown in the query created by the ToTreeDataSourceResult method even when applied to small datasets.

Reproduction of the problem

Please refer to the code below and simply filter the first column with the value of 5.

//View
@(Html.Kendo().TreeList<WebApplication1.Models.SerialModel>()
        .Name("treelist")
         .Toolbar(toolbar => toolbar.Create().Text("New Level"))
        .Columns(columns =>
        {
            columns.Add().Field(e => e.RecordID).Width(280);
            columns.Add().Field(e => e.SerialNumber).Width(160);
            columns.Add().Field(e => e.Name);
            columns.Add().Field(e => e.Location).Width(200);
            columns.Add().Field(e => e.ParentID).Width(140);
            columns.Add().Command(c =>
            {
                c.CreateChild().Text("New Child");
                c.Edit();
                c.Destroy();
               
            }).Width(250);
        })
        .Editable(editable => editable.Mode("inline")).Filterable(true).Filterable(f => f.Extra(false))
        .DataSource(dataSource => dataSource
            .Read(read => read.Action("TreeListData", "Home"))
            //.ServerOperation(false)
            .Model(m =>
            {
                m.Id(f => f.RecordID);
                m.ParentId(f => f.ParentID).DefaultValue("0");
                
            })
        )
        .Height(540)
)

//Controller code: 
public ActionResult TreeListData([DataSourceRequest]DataSourceRequest request, int? id)
        {
            var source = Enumerable.Range(1, 5).Select(x => new SerialModel()
            {
                RecordID = x,
                SerialNumber = x,
                Name = "Name " + x,
                Location = "Location " + x,
                hasChildren =  true,
                ParentID = x < 5 ? 0 : (x / 5)
            });
            return Json(source.ToTreeDataSourceResult(request, e => e.RecordID,
                e => e.ParentID, e => id.HasValue ? e.ParentID == id : e.ParentID == 0, m => m));
        }

Expected/desired behavior

Instead of 1 record it returns 2 same items.

Filtering of the TreeList should be as fast as sorting.

Environment

• Kendo UI version: 2023.1.117

### Bug report

When a non-sortable Grid column header is hovered, the mouse cursor indicates that it is sortable.

### Reproduction of the problem

1. Create a sortable Grid with a non-sortable column.

2. Hover the column header.

3. Mouse cursor is a "pointer".

Here is a dojo sample for reproduction: Untitled | Kendo UI Dojo (telerik.com)

### Expected/desired behavior

Only the headers of the sortable Grid columns should be indicated with a "pointer" when hovered.

### Environment

Kendo UI version: 2022.6.621
jQuery version: 1.12.4
Browser: [all] 

Bug report

Reproduction of the problem

1. Open the following dojo.
2. Open the column menu.
3. Try to remove all columns through the checkboxes.

Current behavior

The last checkbox selection is not disabled and allows all the columns to be removed if the menu options for the command column are explicitly set to false:

Expected/desired behavior

The last checkbox selection should be disabled without allowing all the columns to be removed if the menu options for the command column are explicitly set to false:

The following dojo depicts the aforementioned behavior.

Environment

• Kendo UI version: 2023.3.1010
• jQuery version: x.y
• Browser: [all]

Bug report

When a TreeView is bound to a new kendo.data.HierarchicalDataSource the binding of the widget breaks.

Reproduction of the problem

1. Run this Dojo
2. Notice that when the new DataSource is set the expand icon of the parent disappears.

In the wrappers the following error is thrown:
Uncaught TypeError: Cannot read properties of undefined (reading 'length')

Review the behavior in this Telerik Core REPL.

Expected/desired behavior

The TreeView should bind to the new data set successfully.

Environment

• Kendo UI version: 2023.2.829
• Browser: [all]

Bug report

When a Grid's row is reordered and then the changes are saved - a Destroy request is sent to the server for the dataItem of the reordered row. This happens even though no changes are applied to dataItem of the reordered row.

Reproduction of the problem

1. Run this Telerik REPL or this Dojo
2. Reorder a row
3. Open the browser's Network Tab
4. Click the Save Changes button

Expected/desired behavior

The Grid should request the reordered item to be perished from the backend.

Environment

• Kendo UI version: 2023.2.718

### Bug report

When pasting a table that contains merged cells from Word to the Editor is not formatted correctly.

### Reproduction of the problem

1) Create an Editor as per the example below:

    $("#editor").kendoEditor({
        pasteCleanup: {
          msAllFormatting: false,
          msConvertLists: false,
          msTags: false
        }
    });

2) Copy the table from the attached ".docx" file and paste it into the Editor.

3) The pasted table does not match the table from the Word file.

### Expected/desired behavior

When copying and pasting tables from Word into the Editor, their formatting should match.

### Environment

* **Kendo UI version: 2023.2.718
* **jQuery version: 3.4.1
* **Browser: [all]

In the latest version (2023.2.718), the Column Menu in the Grid faild to open if you set the Groupable option to false.

To reproduce the issue simply change the line below in the Grid Overview Demo

.Groupable(g=>g.ShowFooter(false))

to the following:

.Groupable(false)

https://netcorerepl.telerik.com/cxkhGOvU52pBO4NK33

The error you get when clicking on the Column Menu is:

Uncaught TypeError: Cannot read properties of undefined (reading '_canDrag')
    at init._updateGroupColumns (kendo.all.js:321370:19)
    at init._open (kendo.all.js:321370:19)
    at init.trigger (kendo.all.js:321370:19)
    at init._trigger (kendo.all.js:321370:19)
    at init.open (kendo.all.js:321370:19)
    at init.toggle (kendo.all.js:321370:19)
    at init._click (kendo.all.js:321370:19)
    at HTMLAnchorElement.dispatch (jquery.min.js:3:12445)
    at r.handle (jquery.min.js:3:9174)

Hello,

the "clean formatting" button in the Editor deletes Text.

1. Create unorderd List with 3 entries and 3 indents like:

• Point 1
• Point 2
• Point 3
  • Point 1.1
  • Point 1.2
  • Point 1.3

2. select all the indent Points 1.1 to 1.3 and click the "clean formating" 

clean formatting is cleaning (deleting) the Points 1-3 :

After clean formating looks like this:

Point 1.1

Point 1.2

Point 1.3

It is reproducable on your Demosite

Regards

Michael Pospischil

Bug report

When a user creates a filter with a date, it starts as an empty Datepicker, but the value is appearing as an empty string. Thus, if the user clicks apply, an error appears in the console. If you place a value in the DatePicker and clear it, the value will be Null.

Reproduction of the problem

1. Go to this Progress Telerik ASP.NET Core REPL.
2. Add filter for a Date but keep the datepicker empty.
3. Select apply.
4. Now, add a date and clear the value.

Current behavior

The filter menu sends isnull filter queries in the following format:

While the Filter component sends it as follows:

As a result the ToDataSourceResult method fails.

Expected/desired behavior

If the DatePicker is empty, the filter should properly perform the 'isnull' query upon clicking apply.

Environment

• Kendo UI version: 2023.2.606
• jQuery version: All Supported Versions
• Browser: all

When a Date is already present in the DateTimePicker and the date parts are focused with a mouse click the digits for the year part are cut off.

Reproducable in this Dojo.

Screen recording of the issue.

Bug report

In the Scheduler's Adaptive Rendering mode when the Month view is selected and an event end spans more than a day and ends in 00:00:00 an additional element is rendered for the event.

Reproduction of the problem

1. Run this Dojo
2. Change the View to Week and notice that the event only spans 2 days

Expected/desired behavior

In the Month View of the Scheduler's when Adaptive Rendering is enabled the events should span the correct amount of days.

Environment

• Kendo UI version: 2023.3.1114
• Browser: [all]

Bug report

The DropDownList stretches to adapt to the length of the selected item.

Reproduction of the problem

1. Run this Dojo
2. Change the selected item

Expected/desired behavior

The width of the DropDownList should be consistent.

Environment

• Kendo UI version: 2023.1.314