Using Virtual Scroll in Angular Material 2 Table with @angular/cdk-experimental
I made a custom directive, what can solve this problem:
1) install a package: $ npm install -save ng-table-virtual-scroll
and add it to imports:
import { TableVirtualScrollModule } from 'ng-table-virtual-scroll';
@NgModule({
imports: [
// ...
TableVirtualScrollModule
]
})
export class AppModule { }
2) use the custom DataSource
from the package:
import { TableVirtualScrollDataSource } from 'ng-table-virtual-scroll';
@Component({...})
export class MyComponent {
dataSource = new TableVirtualScrollDataSource();
}
3) use the directive on viewport container:
<cdk-virtual-scroll-viewport tvsItemSize style="height: 400px;">
<table mat-table [dataSource]="dataSource">
...
</table>
</cdk-virtual-scroll-viewport>
The directive allows you to use all features of mat-table
, such as sort, pagination, sticky header/column, etc
This is not something that currently exists out of the box. The CdkTable
(or MatTable
) component does not support virtual scroll YET.
The virtual scroll support baked into @angular/cdk
is still in it's experimental phase - this will change in version 7.
However, when this feature lands the next step will be to implement it for the table. I will explain why.
cdk-virtual-scroll-viewport
is a container for the *cdkVirtualFor
directive, if we look into this directive (CdkVirtualForOf
) we can see that
It implements
CollectionViewer
(code)It accepts (works with)
DataSource
instance (code)
With this in mind, let's look at the CdkTable
It implements
CollectionViewer
(code)It accepts (works with)
DataSource
instance (code)
The similarity is not by chance, the table (with some adjustments) can be used by cdk-virtual-scroll-viewport
like the cdkVirtualFor
is used.
I'm not sure what the final implementation will be, whether the developer will be able to wrap the table from the outside or the table will set it internally but this is the direction it will be.
If I had to guess I would say that the dev will choose if he wants to wrap the table with a virtual scroll. This is because cdk-virtual-scroll-viewport
does not query for cdkVirtualFor
(via ViewChild
), it is passive and waits for something to attach it. Which is a sign that this was thought of pre-hand.
You can do it right now, by extending CdkTable
and making the adjustments yourself, this will require an understanding of the table internals and might take some time. I suggest waiting a bit.