Google Script base64 decode and save file to Drive

Question

I'm receiving a base64encoded image in a Google Sheets script. I can successfully generate an image by logging

e.postData.contents

then using https://www.base64decode.org/ to decode and generate a .jpg file. But when I try to do the decoding inside the google script and write a jpg file to drive, it is corrupted. It looks similar, but there are some replacement characters inserted. Here's my code:

function doPost(e) {
  var decoded = Utilities.base64Decode(e.postData.contents, Utilities.Charset.UTF_8);
  var blob = Utilities.newBlob(decoded);
  DriveApp.createFile('img_'+date+'.jpg', blob.getDataAsString('Windows-1252'), MimeType.JPEG);
}

I also tried blob.getAs('image/jpeg'), but that just returns a 4-byte file containing the text Blob.

Any ideas? I've tried a few different charsets, and Windows-1252 seems to give the closest results.

Answer 1

How about this sample script? When you use this, please define date. In my test, also I could confirm that the base64 encoded jpeg file could be decoded at https://www.base64decode.org/.

And when you updated doPost(), please be careful as follows. Please redeploy your script to Web Apps as a new version. If this is not carried out, script of the deployed Web Apps is not updated.

Sample script :

function doPost(e) {
  var decoded = Utilities.base64Decode(e.parameters.contents, Utilities.Charset.UTF_8);
  var blob = Utilities.newBlob(decoded, "image/jpeg", 'img_'+date+'.jpg'); // Please define date.
  DriveApp.createFile(blob);
}

Curl sample :

If you want to try your doPost() using curl, you can use following command. When you use this, please input filename which is base64 encoded file and Web Apps URL.

curl -L -F "contents=`cat ### Filename ###`" "https://script.google.com/macros/s/#####/exec"

If I misunderstand your question, I'm sorry.