ngOnInit() {
    this.displayLoader = true;
    this.subscription = this.httpClient
      .getSearch(this.pageSize, this.start)
      .subscribe(res => {
        const json = JSON.parse(String(res));
        this.data = json.items;
        this.dataLength = json.total;
        this.displayLoader = false;
      });
  }

  ngOnDestroy() {
    this.subscription.unsubscribe();
  }

  onPageChange(event) {
    if (this.subscription) {
      this.subscription.unsubscribe();
    }
    this.displayLoader = true;
    this.subscription = this.httpClient
      .getSearch(this.pageSize, 10)
      .subscribe(res => {
        const json = JSON.parse(String(res));
        this.data = json.items;
        this.dataLength = json.total;
        this.displayLoader = false;
      });
  }