Table - Lazy Lazy mode is handy to deal with large datasets, instead of loading the entire data, small chunks of data is loaded by invoking onLazyLoad callback everytime paging, sorting and filtering happens. Sample belows imitates lazy paging by using an in memory list.


export class TableLazyDemo implements OnInit {

    datasource: Car[];

    cars: Car[];

    totalRecords: number;

    cols: any[];

    loading: boolean;

    constructor(private carService: CarService) { }

    ngOnInit() {
        //datasource imitation
        this.carService.getCarsLarge().then(cars => {
            this.datasource = cars;
            this.totalRecords = this.datasource.length;
        });

        this.cols = [
            { field: 'vin', header: 'Vin' },
            { field: 'year', header: 'Year' },
            { field: 'brand', header: 'Brand' },
            { field: 'color', header: 'Color' }
        ];

        this.loading = true;
    }

    loadCarsLazy(event: LazyLoadEvent) {
        this.loading = true;

        //in a real application, make a remote request to load data using state metadata from event
        //event.first = First row offset
        //event.rows = Number of rows per page
        //event.sortField = Field name to sort with
        //event.sortOrder = Sort order as number, 1 for asc and -1 for dec
        //filters: FilterMetadata object having field as key and filter value, filter matchMode as value

        //imitate db connection over a network
        setTimeout(() => {
            if (this.datasource) {
                this.cars = this.datasource.slice(event.first, (event.first + event.rows));
                this.loading = false;
            }
        }, 1000);
    }
}


<p-table [columns]="cols" [value]="cars" [lazy]="true" (onLazyLoad)="loadCarsLazy($event)" [paginator]="true" 
    [rows]="10" [totalRecords]="totalRecords" [loading]="loading">
    <ng-template pTemplate="header" let-columns>
        <tr>
            <th *ngFor="let col of columns">
                {{col.header}}
            </th>
        </tr>
    </ng-template>
    <ng-template pTemplate="body" let-rowData let-columns="columns">
        <tr>
            <td *ngFor="let col of columns">
                {{rowData[col.field]}}
            </td>
        </tr>
    </ng-template>
</p-table>