Declined
Last Updated: 11 Dec 2019 13:51 by ADMIN
Charles
Created on: 21 Nov 2019 14:19
Category: Grid
Type: Feature Request
1
Ability to change the behavior of Kendo Grid with virtual scrolling, multiple row selection, persisted selection.

I'd like the ability to choose the behavior of mutli-row selection on a virtual grid with persisted selection.

 

For purpose of example, assume we have a virtual grid with 50 rows (pager controls not shown), a page size of 10, and persisted selection.

1. Select row 1 on page 1.

2. Scroll down to trigger page 2 to load (rows 11-20).

3. Select row 11, page 2.

4. Current Behavior: Both row 1 and row 11 remain selected.

5. Desired Behavior: Only row 11 remains selected.

 

Reasoning: I believe that a virtual scrolling grid should have selection behavior identical to a single page. That means that the only way to add rows to the selection is holding down control/shift during selection. In other words, on page 1 of the above example, if I select row 1, then row 2, only row 2 remains selected. If I select row 1, then Ctrl+click/Shift+click row 2, both remain selected. For virtual scrolling where multiple pages are displayed fluidly as if a single page, it seems odd to have the selection behave differently.

5 comments
ADMIN
Alex Hajigeorgieva
Posted on: 11 Dec 2019 13:51

Hi, Charles,

Thank you for the example.

So in a nutshell, you would like to provide the behaviour of a non-pageable grid with multiple selection like this one:

https://dojo.telerik.com/@bubblemaster/ihulufaW

While it is possible to create the same behaviour with Ctrl key, it is not possible with the Shift key because of this use case:

  • click on the first row
  • scroll fast all the way to the bottom
  • click on one of the rows in the view

The expected behaviour would be when scrolling up that all the previous rows were selected but because of the way the virtually scrollable grid works - the fast scroll means not all of the ranges (pages) were requested. You could achieve the behaviour only for local data. 

Therefore, I am afraid we cannot implement the desired behaviour fully and so we would need to decline this feature request.

Let me know if you need more information.

Kind Regards,
Alex Hajigeorgieva
Progress Telerik

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Charles
Posted on: 04 Dec 2019 15:52

Hi Alex,

Thanks for the details and explanation. I'll try to explain the behavior I'm looking for versus what currently happens, but I think you've touched on it below. 

 

For a virtualized scrolling grid with multiple-row persisted selection (and page size 10 for purpose of example)

1. Select first row, page 1.

2. Scroll down to trigger page 2 to load.

3. Select last row, page 2.

4. Current behavior: first and last row both selected. Desired behavior: only last row remains selected. If I want both first and last row to remain selected, I should be required to hold control during selection.

This desired behavior would make multiple virtual pages behave as a single page in regards to selection. I understand how it currently behaves with paging, and when the paging-controls are displayed it is more intuitive. However, with virtual scrolling the user perceives the grid as a single large page and the current selection behavior is not intuitive since they have no concept of page size or page number. 

For now I'm able to programmatically track the selection collections along with keyup/keydown events in order to clear or add to the current selection depending if users have ctrl/shift pressed. This would be a very nice built in behavior since virtual grids are heavily used in our enterprise applications. 

ADMIN
Alex Hajigeorgieva
Posted on: 28 Nov 2019 07:37

Hello, Charles,

The Kendo UI Grid with virtual scrolling and multiple selection with persistence behaves in exactly the same way as the pageable grid. 

The holding of Ctrl allows multiple selection in different non consecutive rows in the same page. If not holding Ctrl in the same page, the selection is removed. Using drag selection works together with Ctrl and selection is preserved across the pages. 

From a user experience point of view is the Shift selection could be confusing because Shift selects from the selected item all the way to the bottom of the page. However, the user does not know that the grid in virtual scrolling only ever has as many rows as its pageSize and could expect a selection across several pages.

Is this the difference in behaviour that you had in mind? Can explain step by step the expected vs current behaviour?

For example:

1.Click to select the first row

2. Scroll to the bottom of the grid and click to select the last

3. Go to the top - the item is selected and I expected it to be unselected

Here is a runnable Dojo with remote operations grid, multiple selection and virtual scrolling:

https://dojo.telerik.com/@bubblemaster/eFoXujAQ

Look forward to hearing back from you.

Kind Regards,
Alex Hajigeorgieva
Progress Telerik

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Charles
Posted on: 25 Nov 2019 14:27

Hi Alex,

 

Thank you for directing me to that approach. Although it handles the single-row selection correctly, I am interested in having multi-row selection on the virtual scrolling grid. 

 

Overall, in regards to desired selection behavior, I'm looking for a way to make the virtual scrolling grid behave similar to a single page. Building a multi-selection group is done with ctrl/shift+clicking, whereas a normal single click wipes any previous selection and provides only the newly selected row. 

ADMIN
Alex Hajigeorgieva
Posted on: 25 Nov 2019 07:51

Hello, Charles,

While the text in this topic suggests that you are interested in multiple selection, the described behavior in the steps describes persisting single selection.

If this is the case, we have an approach which is listed in the known limitations section how to achieve that:

https://docs.telerik.com/kendo-ui/knowledge-base/grid-virtual-scrolling-with-persist-single-selection

Could you take a look and let us know if this is indeed the desired behaviour?

Kind Regards,
Alex Hajigeorgieva
Progress Telerik

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