<input matInput (keyup)="applyFilter($event.target.value)" placeholder="Search">

applyFilter(filterValue: string) {
      filterValue = filterValue.trim();
      filterValue = filterValue.toLowerCase();
      this.scanService.getFilteringScans(filterValue).subscribe(response => {
        this.scans = response.results;
        this.next = response.next;
        this.previous = response.previous;
        this.scans_length = response.count;
        this.dataSource = new MatTableDataSource(this.scans.map(function(obj){return new ScanDetails(obj)}));
      });
      this.dataSource.filter = filterValue;
  }

getFilteringScans(param): Observable<ScanList> {
    return this.http.get<ScanList>(this.scansUrl + '?search=' + param).pipe(
      map(response => response),
      catchError(this.handleError)
    );
  }