how to convert byte array to pdf and download

Question

I am trying to do a simple task of downloading a http response to a pdf. I am generating a pdf file but I am getting an error of "Failed to open PDF".

Here is what the response looks like.

And here is what I am doing.

 let blob = new Blob([response.data], { type: 'application/pdf' })
 FileSaver.saveAs(blob, 'foo.pdf')

Answer 1

The string from the response seem to be Base-64 encoded (ref. fiddle). You can decode it using fetch() (or XMLHttpRequest() for older browsers):

fetch("data:application/pdf;base64," + response.data)
  .then(function(resp) {return resp.blob()})
  .then(function(blob) {
    FileSaver.saveAs(blob, 'foo.pdf')
  });

Answer 2

If anyone looking for solution with same problem, here is the nice article with cross browser support.

Snippet from article:

const binaryString = window.atob(fileResponseData);
const bytes = new Uint8Array(binaryString.length);
const mappedData = bytes.map((byte, i) => binaryString.charCodeAt(i));
const blob = new Blob([mappedData], { type: 'application/pdf' });
FileSaver.saveAs(blob, 'foo.pdf')