Grid freezes during scrolling (works extremely slow)

[Petr]

Grid scrolling works extremely slow in case of using it with virtualization and sorting. 

Link to reproduce an issue: https://dojo.telerik.com/@WA_PMak/IzevIzaV

Steps to reproduce:

1. Follow the link  https://dojo.telerik.com/@WA_PMak/IzevIzaV
2. Push the Run button
3. Sort by any column (for example by First Name)
4. Scroll grid till it loaded next virtual page
   
   
   Actual result: grid freezes during scrolling.
   Expected result: grid scrolling work fast as it do if it has unsorted data.

[Stefan]

Hello, Petr,

Thank you for the example.

Based on the description I can assume that this is similar to what we are discussing in this forum and in the ticket:

http://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode

I tested the example and the scrolling is smooth on my end:

https://www.screencast.com/t/OJ1wWs9tb7h1

Please share with us the machine parameters and the used browser, so we can try to re-create this.

Also, if this is the same scenario, please let's continue the discussion at only one of the places(this forum, the other forum, the ticket).

Regards,
Stefan
Progress Telerik

[Petr]

[qutoe]Based on the description I can assume that this is similar to what we are discussing in this forum and in the ticket:
http://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode[/qutoe]

No this is a different issue.

• This issue is about scrolling that freezes if filtering and sorting set to grid with inPlacesort set to false. - https://youtu.be/633WCcpOwQY
• The issue http://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode is about sorting brakes then grid scrolling occurs with virtualization=true, inplacesort=true

Those a two different issues. Don't you think so?

[Petr]

[quote]Based on the description I can assume that this is similar to what we are discussing in this forum and in the ticket:
http://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode[/quote]

No you are wrong those a two completely different issues.

 

• This one is about grid freezes while scrolling with inPlaceSort=false - https://youtu.be/633WCcpOwQY
• http://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode this one is about sorting of a grid brakes after scrolling sorted and filtered grid if inPlaceSort=true.

So I strongly believe the new ticket should be created in git hub for it!

[Dimo]

Hello Petr,

Please refer to the related forum thread discussing the case when inPlaceSort is enabled. I have tried to explain how the Grid and the DataSource work in both cases. Let me know if you have additional questions in this thread with regard to the case when inPlaceSort is disabled.

https://www.telerik.com/forums/inplacesort-property-setted-to-true-brakes-sort-if-it-used-together-with-filter-in-virtualisation-mode#jqttuh-zUk6e7hPES0WKjA

Regards,
Dimo
Progress Telerik

[Petr]

This issue is a different issue do not try to mix it with inPlaceSort property on and broken sorting order of a grid issue. 

[Stefan]

Hello, Petr,

Let me provide more details on why we are connecting both issues.

Currently, the sorting can freeze depending on the number of records and the used machine and browser. This means that the Grid is working, but the browser and the machine cannot handle that much DOM manipulations which at its core is not a Kendo UI issue as the Grid is working, it just produces many heavy operations which a specific machine is not able to handle.

As we do understand that the Grid should work faster in order to work smoothly on more machines, we introduced the inPlaceSort property. That is why we are connecting these issues, as fixing the "inPlaceSort" issue will allow fixing the freezing issue when the inPlaceSort property is used.

As the developers are already working on the inPlaceSort issue, I do hope that soon the Grid will be working as expected and your project can successfully continue on track.

Regards,
Stefan
Progress Telerik

[Petr]

[quote]Currently, the sorting can freeze depending on the number of records and the used machine and browser. This means that the Grid is working, but the browser and the machine cannot handle that much DOM manipulations which at its core is not a Kendo UI issue as the Grid is working, it just produces many heavy operations which a specific machine is not able to handle.[/quote]

Nice try Stefan! Can you explain to me why the same grid this the same data works fast with out sorting and filtering and start performing freezeing after sorting and filtering applied? Do you think it is an acceptable behaviour?

[Stefan]

Hello, Petr,

My manager explained in details why this is working fast without the sorting and the filtering. The main reason is that the sorting and the filtering occur on every page changed(scrolling) which is causing the delay.

We do not find this acceptable that is why we introduced the inPlaceSort which will resolve this part of the Grid functionality which can be slower with local data.

We admit that this is not a good behavior, but this is not a separate issue as the fix for it will be using the inPlaceSort, this is the original fix that the developers made for this scenario.

Regards,
Stefan
Progress Telerik

[Petr]

Can I finally know an ETA? I've posted an issue on March the 3rd, your team spent enough time to post an ETA for the issue to my mind!

[Stefan]

Hello, Petr,

The ETA is set once the issue is resolved.

Providing an ETA before that could only be misleading and we avoid setting an ETA before we have a proposal for a fix.

Currently, the developers have pushed a fix and it is in testing. Once it is tested, the milestone of the issue will be updated.

I understand that this may not seems as the perfect approach, but this is our workflow to ensure that a misleading information is not giving to the Kendo UI community.

Regards,
Stefan
Progress Telerik