var x = window.open();
      x.document.open();
      return dataservice.getPDF().then(function (data) {
          vm.imgData ='data:application/pdf;base64, '+data.base64;
          var iframe = "<iframe width='100%' height='100%' src='" + vm.imgData + "'></iframe>";
          x.document.write(iframe);
          x.document.close();
      });