Download base 64 to blob file

downloadBase64BlobFile.js

function downloadBase64BlobFile(response) {
    var blob = b64toBlob(response.data, 'application/vnd.ms-excel');

      if (blob != null && navigator.msSaveBlob) {
          return navigator.msSaveBlob(blob, response.fileName);
      }

      var a = $('<a style=\'display: none;\'/>');
    var url = window.URL.createObjectURL(new Blob([blob], {
      type: 'application/vnd.ms-excel',
      target: '_self'
    }));

    a.attr('href', url);
    a.attr('download', response.fileName);
    $('body').append(a);
    a[0].click();
    $window.URL.revokeObjectURL(url);
    a.remove();
  }

  function b64toBlob(b64Data, contentType, sliceSize) {
    contentType = contentType || '';
    sliceSize = sliceSize || 512;
  
    var byteCharacters = atob(b64Data);
    var byteArrays = [];
  
    for (var offset = 0; offset < byteCharacters.length; offset += sliceSize) {
      var slice = byteCharacters.slice(offset, offset + sliceSize);
  
      var byteNumbers = new Array(slice.length);
      for (var i = 0; i < slice.length; i++) {
        byteNumbers[i] = slice.charCodeAt(i);
      }
  
      var byteArray = new Uint8Array(byteNumbers);
  
      byteArrays.push(byteArray);
    }
      
    var blob = new Blob(byteArrays, {type: contentType});
    return blob;
  }