How to use the igniteui-angular.SortingDirection.Asc function in igniteui-angular

public ngOnInit(): void {
        this.data = DATA;
        this.grid1.sortingExpressions = [
            {
                dir: SortingDirection.Asc, fieldName: "CategoryName",
                ignoreCase: true, strategy: DefaultSortingStrategy.instance()
            }
        ];
    }

public ngOnInit(): void {
        this.data = DATA;
        this.grid1.sortingExpressions = [
            {
                dir: SortingDirection.Asc, fieldName: "CategoryName",
                ignoreCase: true, strategy: DefaultSortingStrategy.instance()
            }
        ];
    }

ngAfterViewInit() {
      this.blockItemService.getItemsList().snapshotChanges().pipe(
         map(actions =>
            actions.map(a => ({ key: a.payload.key, ...a.payload.val() }))
         )
      ).subscribe(items => {
         this.blockItems = items;
      });

      setTimeout(() => {
         this.refreshGrid();
      }, 100);

      this.grid1.sort({ fieldName: 'name', dir: SortingDirection.Asc, ignoreCase: false });
      this.cdr.detectChanges();
   }

public ngOnInit(): void {
        this.localdata = SINGERS;
        this.hierarchicalGrid.sortingExpressions = [
            { dir: SortingDirection.Asc, fieldName: "Artist",
              ignoreCase: true, strategy: DefaultSortingStrategy.instance() }
        ];
    }
    public ngAfterViewInit(): void {

ngAfterViewInit() {
    this.grid1.groupBy({ fieldName: 'dailyScale', dir: SortingDirection.Asc });

    this.refreshGrid();
  }

constructor() {
        this.data = INVOICE_DATA;
        this.expr = [
            { dir: SortingDirection.Asc, fieldName: "ShipCountry", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() },
            { dir: SortingDirection.Asc, fieldName: "ShipCity", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() }
        ];
    }
    public formatDate(val: Date) {

constructor() {
        this.data = INVOICE_DATA;
        this.expr = [
            { dir: SortingDirection.Asc, fieldName: "ShipCountry", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() },
            { dir: SortingDirection.Asc, fieldName: "ShipCity", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() }
        ];
    }
    public formatDate(val: Date) {

constructor() {
        this.data = INVOICE_DATA;
        this.expr = [
            { dir: SortingDirection.Asc, fieldName: "ShipCountry", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() }
        ];

        this.summaryPositions = [
            {
                label: GridSummaryPosition.top,
                selected: this.summaryPosition === GridSummaryPosition.top,
                togglable: true
            },
            {
                label: GridSummaryPosition.bottom,
                selected: this.summaryPosition === GridSummaryPosition.bottom,
                togglable: true
            }
        ];

constructor() {
        this.data = INVOICE_DATA;
        this.expr = [
            { dir: SortingDirection.Asc, fieldName: "ShipCountry", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() },
            { dir: SortingDirection.Asc, fieldName: "ShipCity", ignoreCase: false,
              strategy: DefaultSortingStrategy.instance() }
        ];
    }
    public formatDate(val: Date) {

private _buildDataUrl(virtualizationArgs: any, sortingArgs: any): string {
        let baseQueryString = `${DATA_URL}?$count=true`;
        let scrollingQuery = EMPTY_STRING;
        let orderQuery = EMPTY_STRING;
        let query = EMPTY_STRING;

        if (sortingArgs) {
            let sortingDirection: string;
            switch (sortingArgs.dir) {
                case SortingDirection.Asc:
                    sortingDirection = SortOrder.ASC;
                    break;
                case SortingDirection.Desc:
                    sortingDirection = SortOrder.DESC;
                    break;
                default:
                    sortingDirection = SortOrder.NONE;
            }

            orderQuery = `$orderby=${sortingArgs.fieldName} ${sortingDirection}`;
        }

        if (virtualizationArgs) {
            let requiredChunkSize: number;
            const skip = virtualizationArgs.startIndex;
            requiredChunkSize = virtualizationArgs.chunkSize === 0 ? 11 : virtualizationArgs.chunkSize;