feat(MultiSelect): add IsVirtualize parameter

[EliasIsmail]

Is there an existing issue for this?

• I have searched the existing issues

Is your feature request related to a problem? Please describe the problem.

I was wondering if it would be possible to add Pagination built in to the MultiSelect component.

I have a case in which a Collection of generic/custom objects is shown in the MultiSelect - sometimes, the number of objects is 20.000+. This leads to (maybe as expected) quite sluggish behaviour, when the component is rendered, and especially if you use the "Select all" button for example.

Currently, I have bypassed this by adding a component to the ButtonTemplate child component of the MultiSelect. The Items parameter of the MultiSelect is then bound to a list of objects, that gets updated when the user changes the page (i.e. Skip(pages).Take(pageSize)). This works somewhat, but it can be very tricky to implement and maintain, especially when you factor in the search functionality (which is awesome btw) that the MultiSelect also supports:

<MultiSelect Items="ListUpdatedByPage ... etc"

<ButtonTemplate>
    <Pagination OnPageLinkClick="OnMultiSelectPageLinkClick" PageIndex="GetMultiSelectPageIndex()" PageCount="@GetMultiSelectPageCount()"></Pagination>
 </ButtonTemplate>

</MultiSelect>

So therefore I was wondering, if Pagination in the MultiSelect was ever on the road map? I see that the Table component has it built-in, and this is the exact functionality that would be awesome for MultiSelects with large amount of data.

Kind regards

Describe the solution you'd like

Pagination parameters to the MultiSelect, like what is available in the Table component currently. Alternatively, any kind of Virtualization.

Additional context

No response

[bb-auto]

@EliasIsmail Thank you for contacting us. We will give feedback later.

[ArgoZhang]

@EliasIsmail thank you for submitting the issue. We will add pagination or virtualization technology to support your needs

[ArgoZhang]

@EliasIsmail please try v9.5.0-beta02. If there is no problem, it will be released to the official version later

[EliasIsmail]

Hi Argo,

I tested the v9.5.0-beta02 release. Previously, I have been using the 8.10.1 stable release.

I had issues with making the virtualization work together with the default buttons (select all, reverse, clear). Additionally, I could not get the loading search icon to stop spinning, and could not get the search function to work either (even though I implemented OnQueryAsync as per your demo examples).

I could test the virtualization itself (without searching for anything), which looked to be working just fine - but it was not possible for me to make a final conclusion on it, because of the other issues I faced.

Sorry if I am missing something very obvious in terms of why it was not working!

[ArgoZhang]

@EliasIsmail thank you for the feedback. later I will update the demo on the website.

[ArgoZhang]

@EliasIsmail bump version 9.5.0-beta06. now ShowSearch IsFixedSearch and ShowToolbar can work together.

you can test by following the link
https://www.blazor.zone/multi-select#IsVirtualize