How to convert base64 byte data into downloadable pdf file?

Question

I have an encoded base64 data from an API response and stored in a variable encodedBase64.

let encodedBase64 = 'some base64 encoded long data';

function base64ToArrayBuffer(base64) {
    var binaryString = window.atob(base64);
    console.log('binaryString ', binaryString);
    var binaryLen = binaryString.length;
    var bytes = new Uint8Array(binaryLen);
    for (var i = 0; i < binaryLen; i++) {
       var ascii = binaryString.charCodeAt(i);
       bytes[i] = ascii;
    }
    return bytes;
 }

 function saveByteArray(reportName, byte) {
    var blob = new Blob([byte], {type: "application/pdf"});
    var link = document.createElement('a');
    link.href = window.URL.createObjectURL(blob);
    var fileName = reportName;
    link.download = fileName;
    link.click();
};

var sampleArr = base64ToArrayBuffer(encodedBase64);
saveByteArray("Sample Report", sampleArr); 

after executing this code i am able to download pdf file names SampleReport.pdf but when i open this it is showing Failed to load PDF document. error what is the wrong in my code ?

Answer 1

difficult to get it done using front end side

but it can be done easily using Nodejs using the following code.

fs.writeFile('pdfFileName.pdf', base64DataString, {encoding: 'base64'}, error => {
    if (error) {
        throw error;
    } else {
        console.log('buffer saved!');
    }
});