PrimeNG VirtualScroller in TabView: A Common Headache and Its Solution
PrimeNG's VirtualScroller component is a fantastic tool for handling large datasets efficiently, but pairing it with TabView can sometimes lead to unexpected behavior. This article delves into a common problem users face and presents a robust solution to make your VirtualScroller in TabView work flawlessly.
The Problem: VirtualScroller Losing its Magic Inside TabView
Let's imagine you have a TabView containing multiple tabs, each displaying a list of items using VirtualScroller. The issue arises when you switch between tabs – the VirtualScroller often fails to reload the data for the new tab, resulting in either an empty view or displaying the data from the previously active tab. This behavior can be frustrating and hinder user experience.
Example Code:
<p-tabView>
<p-tabPanel header="Tab 1">
<p-virtualScroller [value]="items1" [items]="items1" [itemSize]="30">
<ng-template let-item pTemplate="item">
{{ item.name }}
</ng-template>
</p-virtualScroller>
</p-tabPanel>
<p-tabPanel header="Tab 2">
<p-virtualScroller [value]="items2" [items]="items2" [itemSize]="30">
<ng-template let-item pTemplate="item">
{{ item.name }}
</ng-template>
</p-virtualScroller>
</p-tabPanel>
</p-tabView>
Why Does This Happen?
The culprit often lies in the way PrimeNG handles VirtualScroller and TabView interactions. When switching tabs, the VirtualScroller might not trigger its data loading mechanism correctly, leading to stale or missing data.
The Solution: Re-initializing the VirtualScroller on Tab Change
The solution lies in manually re-initializing the VirtualScroller component whenever a new tab is activated. We can achieve this using Angular's lifecycle hooks and PrimeNG's built-in methods.
Updated Code:
<p-tabView (onChange)="onTabChange($event)">
<p-tabPanel header="Tab 1">
<p-virtualScroller #scroller1 [value]="items1" [items]="items1" [itemSize]="30">
<ng-template let-item pTemplate="item">
{{ item.name }}
</ng-template>
</p-virtualScroller>
</p-tabPanel>
<p-tabPanel header="Tab 2">
<p-virtualScroller #scroller2 [value]="items2" [items]="items2" [itemSize]="30">
<ng-template let-item pTemplate="item">
{{ item.name }}
</ng-template>
</p-virtualScroller>
</p-tabPanel>
</p-tabView>
import { Component } from '@angular/core';
@Component({
// ...
})
export class AppComponent {
items1: any[] = [];
items2: any[] = [];
onTabChange(event: any) {
if (event.index === 0) {
this.scroller1.refresh(); // Re-initialize VirtualScroller for Tab 1
} else if (event.index === 1) {
this.scroller2.refresh(); // Re-initialize VirtualScroller for Tab 2
}
}
}
Explanation:
- TabView Change Event: We listen to the
onChangeevent of the TabView component to detect tab changes. - VirtualScroller References: We use
#scroller1and#scroller2to get references to the VirtualScroller components in each tab. - Re-initialization: Inside the
onTabChangemethod, we call therefresh()method on the corresponding VirtualScroller based on the newly activated tab. This forces the component to re-fetch and display the correct data.
Additional Tips
- Consider using a common function to handle the re-initialization logic for multiple tabs, reducing code repetition.
- Ensure your data is loaded efficiently and the correct data is available when switching tabs.
- Test thoroughly to ensure your VirtualScroller behaves as expected across different browser versions.
Conclusion
By understanding the issue and implementing the suggested solution, you can seamlessly integrate PrimeNG's VirtualScroller within TabView components. This ensures smooth user experience and efficient data management even when dealing with large datasets.
