Approved
Last Updated: 05 Sep 2019 09:26 by ADMIN
Konstantin
Created on: 22 Aug 2019 12:51
Category: Kendo UI for Angular 2+
Type: Feature Request
3
Add ScrollTop event for Grid

Please, please, please! We have scrollBottom event. It works like a charm. Add the same event for loading prev page on scroll top in [Kendo UI for Angular Grid], plese.

3 comments
ADMIN
Dimiter Topalov
Posted on: 05 Sep 2019 09:26

Hi Konstantin,

The Grid virtual scrolling and endless scrolling functionalities are alternatives to the regular paging (with the pager) functionality, and both are not meant to be used together.

The idea behind using the scrollBottom and scrollTop events is to display only a portion of the whole data (that is larger than what the current Grid height can accommodate so that there is a vertical scrollbar) - for example the Grid is 450px high, each item is 36px high, so that ~ 11-12 items (headers add to the total height too) are visible. When the Grid data contains for example 30 items, there is a vertical scrollbar. When scrolling down and scrollBottom is reached, a new portion of items is added to the end of the list of Grid data, and the corresponding number of items is removed from the beginning. When the user scrolls up, and reaches the top, a new portion of data is loaded in the beginning of the list, and removed from the end.

The Grid virtual scrolling functionality provides an enhanced version of the described behavior out-of-the-box:

https://www.telerik.com/kendo-angular-ui/components/grid/scroll-modes/virtual/

I would also like to point out that this is a feedback portal for sharing ideas and requests for new features and other enhancements. If you have a specific scenario and questions related to how the built-in Grid API and supported functionalities can be used to achieve the desired behavior, please open a private support ticket, and explain the scenario and the desired behavior there. Our Support team will be glad to provide any assistance as per the scope of our support service.

Regards,
Dimiter Topalov
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Konstantin
Posted on: 29 Aug 2019 11:12

Thank you, Dimiter for your effort.

It seems your solution doesn't work when we have grid with paging and user goes to the second page and tries to switch back to the prev page but there are no enough rows to show scroll (e.g. just one row on the page) and scrollbar is not appearing and user can not "scroll" page to back.

Could your please show case with such conditions. And would be perfect if you show an example with scrolltop/virtual scroll features for grid with detail rows (in detail - panel with another grid).

ADMIN
Dimiter Topalov
Posted on: 29 Aug 2019 08:11

Hi Konstantin,

Thank you for submitting this feature request. We will track the customer demand here, and will consider the suggested enhancement, based on the interest and estimated business value.

Meanwhile you can handle the native DOM scroll event of the Grid scrollable container, and perform the desired custom logic when the scrollTop reaches 0 (or other arbitrary number), e.g.:

https://stackblitz.com/edit/angular-y7jcr5-wsrnmx?file=app%2Fapp.component.ts

Regards,
Dimiter Topalov
Progress Telerik

Get quickly onboarded and successful with your Telerik and Kendo UI products with the Virtual Classroom free technical training, available to all active customers. Learn More.