import { SelectionModel } from '@angular/cdk/collections' ; import { Component } from '@angular/core' ; import { MatTableDataSource } from '@angular/material' ; export interface PeriodicElement { name : string ; position : number ; weight : number ; symbol : string ; } const ELEMENT_DATA = [ { position : 1 , name : 'Hydrogen' , weight : 1.0079 , symbol : 'H' } , { position : 2 , name : 'Helium' , weight : 4.0026 , symbol : 'He' } , { position : 3 , name : 'Lithium' , weight : 6.941 , symbol : 'Li' } , { position : 4 , name : 'Beryllium' , weight : 9.0122 , symbol : 'Be' } , { position : 5 , name : 'Boron' , weight : 10.811 , symbol : 'B' } , { position : 6 , name : 'Carbon' , weight : 12.0107 , symbol : 'C' } , { position : 7 , name : 'Nitrogen' , weight : 14.0067 , symbol : 'N' } , { position : 8 , name : 'Oxygen' , weight : 15.9994 , symbol : 'O' } , { position : 9 , name : 'Fluorine' , weight : 18.9984 , symbol : 'F' } , { position : 10 , name : 'Neon' , weight : 20.1797 , symbol : 'Ne' } , ] ; title @ Component ( { selector : 'table-selection-example' , styleUrls : [ 'table-selection-example.css' ] , templateUrl : 'table-selection-example.html' , } ) export class TableSelectionExample { displayedColumns : string [ ] = [ 'select' , 'position' , 'name' , 'weight' , 'symbol' ] ; dataSource = new MatTableDataSource < PeriodicElement > ( ELEMENT_DATA ) ; selection = new SelectionModel < PeriodicElement > ( true , [ ] ) ; /** Whether the number of selected elements matches the total number of rows. */ isAllSelected ( ) { const numSelected = this . selection . selected . length ; const numRows = this . dataSource . data . length ; return numSelected === numRows ; } /** Selects all rows if they are not all selected; otherwise clear selection. */ masterToggle ( ) { this . isAllSelected ( ) ? this . selection . clear ( ) : this . dataSource . data . forEach ( row => this . selection . select ( row ) ) ; } }