On the kendo editor for angular, when the toolbar controls for both background color and foreground color are present and I select a background color, the color chosen for background is shown in the swatch for both the back ground and foreground buttons even though nothing has been selected in the foreground

Hello Kendo UI for Angular team,
We found a memory leak in the Kendo UI for Angular DateTimePicker and would like to ask you to fix it. Every time the popup is opened and closed, the complete popup DOM (about 2,000 nodes) and one keydown listener stay in memory until the DateTimePicker itself is destroyed. We could not find an existing report on GitHub, the feedback portal or the forums.

ENVIRONMENT
- @progress/kendo-angular-dateinputs 23.4.0 (our version). The same code is in 24.2.2, in 25.3.0 and in the bundle of your online demo.
- Angular 21.2, RxJS 7.8, Chrome 153, production build.
- Default calendarType ('infinite').

STEPS TO REPRODUCE (on your online demo)
1. Open https://demos.telerik.com/kendo-angular-ui/demos/dateinputs/datetimepicker/basic_usage in Chrome.
2. Open DevTools > Performance monitor (DOM Nodes, JS event listeners), or the Memory tab.
3. Open the popup with the calendar button and close it with Escape. Repeat 8 times.
4. Collect garbage (Memory tab > "Collect garbage") and take a heap snapshot. Filter by "Detached".

ACTUAL RESULT
After forced garbage collection following each cycle:
- DOM nodes: 122 → 2,452 → 4,497 → 6,542 → 8,587 → 10,632 → 12,677 → 14,722 → 16,767 (about +2,045 per open).
- JS event listeners: 63 → 71 (+1 per open).
- The heap snapshot contains 8 detached table.k-calendar-table elements, each with its whole popup subtree, retained by an RxJS subscription teardown.
Closing with Cancel, Set or the toggle button behaves the same. In the same setup, the DatePicker and TimePicker do not grow.

EXPECTED RESULT
After the popup closes and garbage is collected, the DOM node and listener counts return to their previous level.

ROOT CAUSE
For the infinite calendar, DateTimePickerComponent.openPopup() adds a keydown subscription on the month list to the component-lifetime `subscriptions`:
    if (this.calendar.type === 'infinite') {
        this.subscriptions.add(fromEvent(this.calendar.monthView.list.nativeElement, 'keydown').subscribe((event) => {
            ...
        }));
    }
(fesm2022/progress-kendo-angular-dateinputs.mjs: line 16741 in 23.4.0, line 18024 in 25.3.0.)
closePopup() unsubscribes ariaActiveDescendantSubscription, but not this subscription, and `subscriptions` is only unsubscribed in ngOnDestroy(). Every open therefore adds another listener on the new calendar table, and that listener keeps the closed popup alive.

SUGGESTED FIX
Keep the subscription per popup and release it when the popup closes, for example:
    private calendarKeydownSubscription: Subscription | null = null;
    // openPopup()
    if (this.calendar.type === 'infinite') {
        this.calendarKeydownSubscription = fromEvent(this.calendar.monthView.list.nativeElement, 'keydown').subscribe((event) => {
            ...
        });
    }
    // closePopup() and ngOnDestroy()
    this.calendarKeydownSubscription?.unsubscribe();
    this.calendarKeydownSubscription = null;

IMPACT
We use the DateTimePicker in form fields and in the filter row of a data grid, where the picker lives as long as the grid is shown. Each open adds about 2,000 detached DOM nodes, so memory keeps growing on long-lived screens (100 opens leave about 200,000 detached nodes) until the user leaves the page. Because `subscriptions` is private, we cannot release the subscription cleanly from application code. The subscription is only created for the infinite calendar, but switching to calendarType 'classic' is not an option for us because it changes the calendar experience.

REQUEST
- Please confirm the issue and fix it in an upcoming release, and let us know which version will include the fix.
- If you track it publicly (feedback portal or GitHub), please send us the link so we can follow it.
- Please let us know whether there is a supported workaround until the fix is released.
We are happy to share heap snapshots and our automated Playwright reproduction script.

Kind regards,
Kamil

Hello,

Please repeat the following steps to reproduce this issue:

Please repeat the following steps to reproduce this critical accessibility issue:

Hi,

in a Treeview bound to flat data (probably does not matter), if I have 3 items, and I drop the first 2 in the last, the loading indicator is stuck.

Stackblitz repro: https://stackblitz.com/edit/angular-xiwrcwsx?file=src%2Fapp%2Fapp.component.ts

Can you please take a look at it?

Best regards,
Michael

`ZonedDate.fromLocalDate(new Date('2025-10-26T00:00:00.000Z'), TIME_ZONE_ID_EUROPE_BERLIN)`returns hour **1**, although the correct local hour is **2** (CEST, UTC+2). Berlin switches back at **2025-10-26T01:00:00Z**, not at midnight UTC. The two consecutive UTC instants `00:00Z` and `01:00Z` must both display `02:00`, with different offsets.

I tested the behavior with time zones 'Europe/Berlin' and 'Australia/Hobart'.

I tried to attach a Markdown file here, but upload failed for whatever reason. You wiil find the detailed description in the Markdown below:

In firefox, open the Kendo Radio Button documentation and slowly resize the window (https://www.telerik.com/kendo-angular-ui/components/inputs/radiobutton)

The radio button will kind of jiggle around and occasionally the white dot in the radio button will become off-center.

This also seems to happen in response to some material bouncy (cubic-bezier) animation transitions.

Hi,

This works with Angular 20, must be a change related to that.

If I assign data to the TreeView synchronously, it works, but e.g. in a setTimeout, it doesn't any more. (I assign the full array, change detection is set to eager.)

Reproduction can be found here: https://codesandbox.io/p/devbox/mutable-glade-39twhs?workspaceId=ws_P4gPDf6RC2r5W8xExWQehV

Best regards,
Michael

Further Environment Informations

Component: @progress/kendo-angular-treeview
Severity: regression (worked in v23, broken in v24)

rxjs: 7.8.2

zone.js 0.15.1 (zone-based, not zoneless)

typescript 6.0.3

Summary

When a flat [nodes] array is bound to kendo-treeview and the array reference is replaced after the first change-detection pass, the TreeView keeps rendering the initial nodes and never reflects the new data. In v23.x the same binding updated correctly.

Minimal reproduction (standalone, drop into a blank Angular 22 app / StackBlitz)

import { Component, signal } from '@angular/core';
import { bootstrapApplication } from '@angular/platform-browser';
import { TreeViewModule } from '@progress/kendo-angular-treeview';

interface Node { name: string; }

@Component({
  selector: 'app-root',
  standalone: true,
  imports: [TreeViewModule],
  template: `
    <button (click)="replaceNodes()">Replace nodes</button>

    <p>Plain list (control — reflects the current data):</p>
    <ul>
      @for (n of nodes(); track n.name) { <li>{{ n.name }}</li> }
    </ul>

    <p>Kendo TreeView (bug — stays on the initial data):</p>
    <kendo-treeview
      [nodes]="nodes()"
      textField="name"
      [kendoTreeViewSelectable]="{ enabled: false }"
    >
      <ng-template kendoTreeViewNodeTemplate let-dataItem>
        {{ dataItem.name }}
      </ng-template>
    </kendo-treeview>
  `,
})
export class AppComponent {
  protected readonly nodes = signal<Node[]>([{ name: 'A' }, { name: 'B' }]);
  protected replaceNodes(): void {
    this.nodes.set([{ name: 'X' }, { name: 'Y' }, { name: 'Z' }]);
  }
}

bootstrapApplication(AppComponent).catch(err => console.error(err));

Steps to reproduce

1. Load the component — TreeView renders A, B.
2. Click Replace nodes (assigns a brand-new array [X, Y, Z]).

Expected

The TreeView re-renders and shows X, Y, Z (like the plain <ul> control right above it, which updates correctly — proving the data really changed and change detection ran).

Actual (v24.2.2)

The TreeView still shows A, B. The new [nodes] reference is ignored.

Regression

Identical code updated correctly on @progress/kendo-angular-treeview 23.x. It broke on the upgrade to 24.x. Bisecting across 24.0.0 → 24.2.2 would pinpoint the exact patch.

Current workaround

Force the TreeView to be destroyed and recreated whenever the data reference changes:
@for (nodes of [data()]; track nodes) {
  <kendo-treeview [nodes]="nodes" textField="name" ...>...</kendo-treeview>
}
This works but is obviously undesirable (full teardown/rebuild on every data change, loss of internal state).

`@progress/kendo-intl` incorrectly formats timezone offsets whose minute component is non-zero.

For example, a JavaScript `Date` with the historical Warsaw offset `UTC+01:24` is formatted as `+01:04` instead of `+01:24`.

This affects all tested `Z`, `X`, and `x` timezone format variants.

Environment

- `@progress/kendo-angular-intl`: `24.2.0`
- `@progress/kendo-intl`: `3.2.1`

- Browser/Node timezone: `Europe/Warsaw`
- Operating system: Windows
- Format: `yyyy-MM-ddTHH:mm:ssZZZZZ`

The same formatting implementation appears in `@progress/kendo-intl` versions `3.1.2` and `3.2.1`.

Reproduction

const { formatDate } = require('@progress/kendo-intl');

process.env.TZ = 'Europe/Warsaw';

const date = new Date(1900, 0, 1, 16, 0, 0);

console.log(date.toString());
console.log(date.getTimezoneOffset());
console.log(formatDate(date, 'yyyy-MM-ddTHH:mm:ssZZZZZ'));

Actual Result

Mon Jan 01 1900 16:00:00 GMT+0124
-84
1900-01-01T16:00:00+01:04

Expected Result

1900-01-01T16:00:00+01:24

Date#getTimezoneOffset() returns -84, meaning the local timezone is 84 minutes ahead of UTC:

84 minutes = 1 hour 24 minutes

Other Examples

The issue is not limited to positive offsets:

UTC is also formatted differently depending on the token, but that behavior may be intentional:

Tested Format Specifiers

All applicable format variants use the same incorrect minute calculation:

Z      -> +0104
ZZ     -> +0104
ZZZ    -> +0104
ZZZZ   -> GMT+01:04
ZZZZZ  -> +01:04

X      -> +0104
XX     -> +0104
XXX    -> +01:04
XXXX   -> +0104
XXXXX  -> +01:04

x      -> +0104
xxx    -> +01:04
xxxxx  -> +01:04

Changing from ZZZZZ to XXXXX or XXX therefore does not resolve the problem.

Suspected Root Cause

The current formatter appears to perform approximately this calculation:

const offset = date.getTimezoneOffset() / 60;
const hoursMinutes = Math.abs(offset).toString().split('.');
const minutes = hoursMinutes[1] || 0;

For an 84-minute offset:

84 / 60 = 1.4

The decimal portion "4" is then treated as four minutes and padded to "04".

However, the fractional part represents a fraction of an hour:

0.4 hours * 60 = 24 minutes

Likewise, for 210 minutes:

210 / 60 = 3.5

The formatter produces 03:05, although 0.5 hours is 30 minutes.

Suggested Fix

Timezone offsets should remain integer minute values throughout formatting:

function formatTimeZone(date, info, options) {
    const totalMinutes = date.getTimezoneOffset();
    const absoluteMinutes = Math.abs(totalMinutes);
    const hours = Math.floor(absoluteMinutes / 60);
    const minutes = absoluteMinutes % 60;
    const sign = totalMinutes <= 0 ? '+' : '-';

    // Continue applying shortHours, separator, optionalMinutes,
    // localizedName and zZeroOffset options using hours and minutes.
}

The important calculations are:

const hours = Math.floor(Math.abs(offsetMinutes) / 60);
const minutes = Math.abs(offsetMinutes) % 60;

Converting the offset to a decimal hour and splitting its string representation is not reliable.

Suggested Regression Tests

it('formats a positive timezone offset with minutes', () => {
    const date = new Date(2024, 5, 25, 12, 7, 5);
    vi.spyOn(date, 'getTimezoneOffset').mockReturnValue(-84);

    expect(formatDate(date, 'yyyy-MM-ddTHH:mm:ssZZZZZ'))
        .toBe('2024-06-25T12:07:05+01:24');
});

it('formats a negative timezone offset with minutes', () => {
    const date = new Date(2024, 5, 25, 12, 7, 5);
    vi.spyOn(date, 'getTimezoneOffset').mockReturnValue(210);

    expect(formatDate(date, 'yyyy-MM-ddTHH:mm:ssZZZZZ'))
        .toBe('2024-06-25T12:07:05-03:30');
});

Other useful cases include:

-345 -> +05:45
-330 -> +05:30
210 -> -03:30
0 -> Z or +00:00, depending on the selected token

Impact

This can corrupt serialized date-time values when they are passed to systems that honor the emitted offset, including .NET DateTimeOffset.

Example:

Intended: 1900-01-01T16:00:00+01:24
Emitted:  1900-01-01T16:00:00+01:04

These values represent instants 20 minutes apart.

The issue affects:

• Historical dates from regions that previously used local mean time.
• Current timezones with half-hour or quarter-hour offsets.
• Any test or custom Date implementation returning a non-whole-hour offset.

Examples of modern fractional offsets include UTC+05:30, UTC+05:45, UTC+09:30, and UTC-03:30.

Additional Context

We initially encountered this with Europe/Warsaw and 1900-01-01. The JavaScript runtime correctly reports Warsaw's historical offset as UTC+01:24. The incorrect UTC+01:04 value is introduced only during Kendo formatting.

We have implemented a temporary application-level workaround that formats the date portion with Kendo and calculates the timezone offset directly from integer minutes.

StackBlitz

Hello,

I have prepared an example, here's how you reproduce the bug (https://stackblitz.com/edit/angular-2nwrn7db?file=src%2Fapp%2Fapp.component.ts):

1. Move the Product Name column between the Category and Unit Price columns
2. Save the Grid state using the Save State button
3. Reload the page
4. Restore the saved state using the Load State button
5. The multi-column Test (k-grid0-col4) has the wrong OrderIndex (0 instead of 4)

Best regards,

Igor

When dateinput format is "d/M/y" and "allowCaretMode" is enabled, users are unable to enter valid dates. Tested with dateinput and datepicker components.

Steps to reproduce

1. Setup a kendo-dateinput component with "allowCaretMode" set to "true" and the "format" set to "d/M/y" (see stackblitz below).
2. Enter a valid single-digit day and valid single-digit month into the input.
3. Try typing a year.
4. Observe that only one character of the year can be entered and the input locks up, preventing the user from completing a valid date.
5. Try typing a double digit month.
6. Observe that only one character of the month can be entered and the input locks up.
7. Try typing a double digit day.
8. Observe that only one character of the day can be entered and the input locks up.

Stackblitz example - angular v22 + kendo v24

https://stackblitz.com/edit/angular-kendo-dateinput-bug-rdocwtvr

Expected Behaviour:

The user should be able to enter a full year, month, and day after typing a valid single-digit day and month.

Observed Behaviour:

After entering a single-digit day and month, the input locks up, preventing the user from typing more than one character for the year or month. This prevents users from entering valid dates, making the input unusable in this scenario.

Thanks

For the Kendo DatePicker, if you try to set the size on a kendo-datepicker with plain text, it will not render and give a console error of "ERROR TypeError: Cannot read properties of undefined (reading 'nativeElement')".

Errors:

// HTML
<kendo-datepicker size="small" ... />

---

But on the other hand, it does work if you create a field of type "DateInputSize" and pass that variable to the size.

// TS
protected size: DateInputSize = 'small';
 

// HTML
<kendo-datepicker [size]="size" ... />

Hi,

We're heavily using the Scheduler component, but we've hit a problem with `slotClick` in scenarios involving multiple scheduler instances on the same page.

With two schedulers on one page, slot detection for the second scheduler (used in context-menu flows via slotByPosition) can be wrong.

Detaild repro: Stackblitz

When enabling the showSelectAll option in a checkbox column on the TreeList component, a checkbox is rendered with the TreeListSelectAllCheckboxDirective. In its constructor, this directive includes some logic that causes the TreeList to instantiate a new ViewCollection every time a selection change occurs. However, the call to ViewCollection.loadView() does not pass the service responsible for determining expanded nodes, so the default fallback (which returns true for all nodes) is used.

Problem

• Unnecessary and potentially expensive backend calls

• Performance degradation, especially with large datasets

• Inefficient "select all" logic that does not respect the current loaded/visible state

This behavior appears to ignore the fact that TreeList is configured for remote data binding with lazy-loaded children.

Expected Behavior

• showSelectAll should only evaluate the currently loaded and visible items

• fetchChildren() should not be called for every node

• Integration with remote/lazy-loaded data should be respected

Suggested Solutions

1. Update TreeListSelectAllCheckboxDirective to properly integrate with the expanded node detection logic or allow injection of a custom service.

2. Provide an override or callback to control the behavior of the "select all" checkbox manually in remote scenarios.

Steps to Reproduce

1. Configure a TreeList with hasChildren and children to fetch child nodes lazily.

2. Enable selection with checkbox column and showSelectAll: true.

3. Click any checkbox inside the TreeList.

4. Observe that fetchChildren() is triggered for all nodes, not just expanded ones.

StackBlitz repro:

Open console and click on the first cell. 

https://stackblitz.com/edit/angular-e2ai4pjx?file=src%2Fapp%2Fapp.component.ts,angular.json