possibly code for saving data uri image to s3

datauri_to_s3.js

var filename = 'my_data_pic.png';
var photoData = req.body.photoData;

// convert to buffer
var photo_buffer = new Buffer(b64str, 'base64');

// prepare database record
var photoPost = new Photo(); // create Blog object

// pick the Amazon S3 Bucket
var s3bucket = new AWS.S3({params: {Bucket: 'dwd_uploads'}});

// Set the bucket object properties
// Key == filename
// Body == contents of file
// ACL == Should it be public? Private?
// ContentType == MimeType of file ie. image/jpeg.
var params = {
  Key: filename,
  Body: photo_buffer,
  ACL: 'public-read',
  ContentType: mimeType
};

// Put the Object in the Bucket
s3bucket.putObject(params, function(err, data) {
  if (err) {
    console.log(err)

  } else {
    console.log("Successfully uploaded data to s3 bucket");

    // add image to blog post
    photoPost.image = filename;
  }

  photoPost.save();

  res.redirect('/');

});

You can do this on front-end also by simply decoding the 64 bit data URI to original file content as follows

1. Store your Data URI in a variable.

2. Create function which decodes your data URI(64 bit encoded string) to string(Here I have created dataURItoBlob() function) and after 3 decoding return the string.

3. Pass that string to in body of S3 upload function.

        `var myDataUri = "data:application/pdf;base64,JVBERi0xLjMKMyAwIG9iago8PC9UeXBlIC9QYW..."
         var myFile=dataURItoBlob(myDataUri);
         function dataURItoBlob(dataURI) {
                 console.log('1: ',dataURI);
                 var binary = atob(dataURI.split(',')[1]);
                 var array = [];
                 console.log('2: ',binary.length);
                 for (var i = 0; i < binary.length; i++) {
                       array.push(binary.charCodeAt(i));
                 }
                return new Blob([new Uint8Array(array)], {
                type: 'application/pdf'
              });
         }
   
        if (myFile)) {
           results.innerHTML = '';
           var params = {
           Key: new Date().getTime() + '.pdf',
          ContentType: 'application/pdf',
          Body: myFile
          };
   
      bucket.upload(params, function(err, data) {
           results.innerHTML = err ? 'ERROR!' : 'UPLOADED.: ' + file;
      });
     } else {
    results.innerHTML = 'Nothing to upload.';`
   

You can send this decoded data to printer also.