VirtualScroller triggers onLazyLoad event even though there is no scroll event.

[bnymncoskuner]

Describe the bug

VirtualScroller triggers onLazyLoad event even though there is no scroll event.

You can view the console on this demo

Open up the console and you will see the event being logged constantly.

Environment

Simple angular project with latest version of angular and primeng

Reproducer

https://stackblitz.com/edit/primeng-virtualscroller-demo-cqpv7h

Angular version

14.2.3

PrimeNG version

14.1.2

Build / Runtime

Angular CLI App

Language

TypeScript

Node version (for AoT issues node --version)

16.14.2

Browser(s)

No response

Steps to reproduce the behavior

1. Open up the console
2. You'll see the event being logged constantly.

Expected behavior

I would expect the lazyLoad event to trigger when there is a scroll event.

[yelhouti]

Is this a regression ? I am facing the same issue in dropdowns, the same event shouldn't be triggered twice

[yelhouti]

@mertsincan I see that you are the one who worked on VirtualScoll. It is complitelly broken when lazy, specifically when working with dropdowns.
Even the primeng demo is broken...

[cetincakiroglu]

Hi,

Thanks for reporting the issue, I added it to the milestone

[mnhock]

We have the same issue triggering endless events for virtual scroll / lazyload mode in p-dialog component.

[yelhouti]

@mnhock I am working on a PR that also fixes lazy to work with filters

[mnhock]

Thank you so much @yelhouti ! I appreciate the work of your guys!

[yelhouti]

@mnhock I am just a user of the library like you :)

[yelhouti]

@mnhock for the dropdown, the issue was because of a scroll that triggered the reload, I suspect the same thing happens in your component. I am fixing dropdown and multiselect for now

[yelhouti]

@cetincakiroglu could you check the PR please, Also I an unable to run ng build locally:

Debug Failure. False expression: Non-string value passed to ts.resolveTypeReferenceDirective, likely by a wrapping package working with an outdated resolveTypeReferenceDirectives signature. This is probably not a problem in TS itself.

It seems like an issue witch package versions, could you please tell the node version you are using? and also can you ensure that when you remove node_modules and reinstall it keeps building.

Thanks in advance

Edit: fixed by updating ng-package to match angular version pushed that too

[ThorstenKunz]

Same thing happens to us with p-table when used with virtualscroll and lazy: endless calls of onLazyLoad method even when no scoll event is happening.

[mertsincan]

For performance, you can use event.forceUpdate(); instead of this.virtualProducts = [...this.virtualProducts];.