angular download blob pdf

getPDF(){
      this.apiService.getPDF(this.invoiceId)
      .subscribe(
        (data: Blob) => {
          var file = new Blob([data], { type: 'application/pdf' })
          var fileURL = URL.createObjectURL(file);

// if you want to open PDF in new tab
          window.open(fileURL); 
          var a         = document.createElement('a');
          a.href        = fileURL; 
          a.target      = '_blank';
          a.download    = 'bill.pdf';
          document.body.appendChild(a);
          a.click();
        },
        (error) => {
          console.log('getPDF error: ',error);
        }
      );
    }