Dropdownlist opens very slow with big dataset

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Last Updated: 20 Jun 2023 08:00 by ADMIN

Katja

Created on: 02 Jun 2023 13:34

Category: UI for Blazor

Type: Bug Report

Dropdownlist opens very slow with big dataset

Hi,

When we use the TelerikDropDownList with a large amount of data (client side) in Blazor, the dropdown takes several seconds to open the popup. (*)
Even with the most simple version of the TelerikDropDownList component:

<TelerikDropDownList Data=@Logic.LuNacebelCodes
                    TextField="DisplayName"
                    ValueField="Id"
                    @bind-Value=@dto.Party.LuNacebelCodeId
                    Filterable="true" FilterOperator="@StringFilterOperator.Contains">
    <DropDownListSettings>
        <DropDownListPopupSettings Height="200px" />
    </DropDownListSettings>
</TelerikDropDownList>

But isn't it strange the same dropdownlist in Kendo for jQuery (AngularJS) with exactly the same dataset, doesn't react slow and opens on the fly..?
Is the DOM manipulation in Blazor that much slower then?

(*) We know Virtualization fixes this problem, but it has some limitations.

Thanks in advance.

5 comments

ADMIN

Hristian Stefanov

Posted on: 20 Jun 2023 08:00

Hi Katja,

Thank you for updating me and sharing your feedback. I'm glad to see that the virtualization works for you after all.

Please be assured that if any better alternatives appear, I will add them as a comment here.

Regards,
Hristian Stefanov
Progress Telerik

As of R2 2023, the default icon type will be SVG instead of Font. See this blogpost for more information.

Katja

Posted on: 16 Jun 2023 10:55

Hi Hristian,

We already expected Blazor to be the culprit, but wanted to verify anyway. We use the virtualization scroll mode now for the dropdown with this dataset. The limitation of virtualization I was talking about, is the known one on your Dropdownlist virtualization page.. So when the initially selected item is not on the first page, the dropdown will not scroll the list to the selected item when opening.
But that's something we and our users can live with.

Thanks for the effort and explanations.

Regards

ADMIN

Hristian Stefanov

Posted on: 16 Jun 2023 09:13

Hi Katja,

Thank you for getting back to me with additional information.

After extensive discussions and explorations with the development team, I can now confirm that the current performance with such an amount of items is inherent to the Blazor framework itself. It is also true that Blazor's DOM manipulation is relatively slower compared to Kendo. Specifically, in the case of having 943 items, Blazor renders 943 components upon opening the dropdown.

Upon reviewing the implementation of our Blazor TelerikDropDownlist component, I can assure you that it does not contain any specific elements contributing to the observed slow performance.

In light of these findings, the recommended solution is to leverage virtualization. Can you please specify which limitation within the virtualization feature is problematic for your particular scenario?

Additionally, I want to assure you that if there are any potential enhancements that could improve the performance of our dropdown, I will make sure to add them as comments to the relevant item. Our team is dedicated to continually optimizing and refining our components to meet the needs of our users.

Regards,
Hristian Stefanov
Progress Telerik

As of R2 2023, the default icon type will be SVG instead of Font. See this blogpost for more information.

Katja

Posted on: 09 Jun 2023 15:07

Hi Hristian,

The data array has 943 items. The item length ranges from 13 to 158, with an average of 55.
If really necessary, I can email you the data array in json.

Regards

ADMIN

Hristian Stefanov

Posted on: 09 Jun 2023 12:11

Hi Katja,

Thank you for sharing the DropDownList configuration with me.

Before we proceed further, can you please provide me with the specific amount of data you are currently working with? This will allow me to conduct proper testing on my end.

I eagerly await your response and appreciate your cooperation.

Regards,
Hristian Stefanov
Progress Telerik

As of R2 2023, the default icon type will be SVG instead of Font. See this blogpost for more information.