I would like to make filterPredicate to work with empty filter string.
html:
<mat-form-field>
<mat-label>Filter</mat-label>
<input matInput (keyup)="applyFilter($event)" placeholder="Ex. ium" #input>
</mat-form-field>
<table mat-table [dataSource]="dataSource" class="mat-elevation-z8">
<!-- Position Column -->
<ng-container matColumnDef="position">
<th mat-header-cell *matHeaderCellDef> No. </th>
<td mat-cell *matCellDef="let element"> {{element.position}} </td>
</ng-container>
<!-- Name Column -->
<ng-container matColumnDef="name">
<th mat-header-cell *matHeaderCellDef> Name </th>
<td mat-cell *matCellDef="let element"> {{element.name}} </td>
</ng-container>
<!-- Weight Column -->
<ng-container matColumnDef="weight">
<th mat-header-cell *matHeaderCellDef> Weight </th>
<td mat-cell *matCellDef="let element"> {{element.weight}} </td>
</ng-container>
<!-- Symbol Column -->
<ng-container matColumnDef="symbol">
<th mat-header-cell *matHeaderCellDef> Symbol </th>
<td mat-cell *matCellDef="let element"> {{element.symbol}} </td>
</ng-container>
<tr mat-header-row *matHeaderRowDef="displayedColumns"></tr>
<tr mat-row *matRowDef="let row; columns: displayedColumns;" [hidden]="row.disabled == true"></tr>
<!-- Row shown when there is no matching data. -->
<tr class="mat-row" *matNoDataRow>
<td class="mat-cell" colspan="4">No data matching the filter "{{input.value}}"</td>
</tr>
</table>
<div [hidden]="dataSource.paginator == null">
<mat-paginator pageSize="10" [pageSizeOptions]="[3, 5, 10]" showFirstLastButtons></mat-paginator>
</div>
ts:
import { Component, OnInit, AfterViewInit, ViewChild } from "@angular/core";
import { MatTableDataSource } from "@angular/material/table";
import { MatPaginator } from "@angular/material/paginator";
export interface PeriodicElement {
name: string;
position: number;
weight: number;
symbol: string;
disabled: boolean;
}
const ELEMENT_DATA: PeriodicElement[] = [
{position: 1, name: 'Hydrogen', weight: 1.0079, symbol: 'H', disabled: false},
{position: 2, name: 'Helium', weight: 4.0026, symbol: 'He', disabled: false},
{position: 3, name: 'Lithium', weight: 6.941, symbol: 'Li', disabled: false},
{position: 4, name: 'Beryllium', weight: 9.0122, symbol: 'Be', disabled: false},
{position: 5, name: 'Boron', weight: 10.811, symbol: 'B', disabled: false},
{position: 6, name: 'Carbon', weight: 12.0107, symbol: 'C', disabled: false},
{position: 7, name: 'Nitrogen', weight: 14.0067, symbol: 'N', disabled: false},
{position: 8, name: 'Oxygen', weight: 15.9994, symbol: 'O', disabled: true}, // should be hidden.
{position: 9, name: 'Fluorine', weight: 18.9984, symbol: 'F', disabled: true}, // should be hidden.
{position: 10, name: 'Neon', weight: 20.1797, symbol: 'Ne', disabled: true}, // should be hidden.
];
@Component({
selector: "my-app",
templateUrl: "./app.component.html",
styleUrls: ["./app.component.css"]
})
export class AppComponent implements OnInit, AfterViewInit {
displayedColumns: string[] = ["position", "name", "weight", "symbol"];
dataSource = new MatTableDataSource(ELEMENT_DATA);
@ViewChild(MatPaginator) paginator!: MatPaginator;
ngOnInit(): void {
// This does not run in case filter is empty.
this.dataSource.filterPredicate = (
data: PeriodicElement,
filter: string
) => {
if (data.disabled) {
return false;
}
if (data.name.toLowerCase().indexOf(filter) > -1) {
return true;
}
return false;
};
}
ngAfterViewInit(): void {
this.dataSource.paginator = this.paginator;
}
applyFilter(event: Event) {
const filterValue = (event.target as HTMLInputElement).value;
this.dataSource.filter = filterValue.trim().toLowerCase();
}
}
I would like to hide rows which have disabled:true (position 8, 9, 10 in the example above).
In my previous post, I first tried to set filterPredicate. But this does not work in case filter string is empty. So I set [hidden] parameter in html as below.
<tr mat-row *matRowDef="let row; columns: displayedColumns;" [hidden]="row.disabled == true"></tr>
This looks fine, but I have a problem.
When the table is shown with paginator, the paginator's row count does not match dispalyed rows count.
This is Stackblitz sample. 7 rows are shown, but paginator's row count are 10.
I guess everything will be good if filterPredicate can be applied with empty filter string.
Do I have a way for filterPredicate to work even for empty string? Or do I have another solutions for this problem?
