HTML drag/drop - how to set the filename of an *outgoing* drag (to desktop)

Question

I\'m trying to make it so a user can drag an icon from the web browser to their desktop, and a text file is created. I\'ve got the content part down, but I can\'t figure out how

Answer 1

Argh! The below works fine in Chrome:

const jsonData = JSON.stringify(dat);
event.dataTransfer.setData("DownloadURL", "application/json:crashdump.json:data:application/json;charset=utf-8," + jsonData);

Though not in Safari nor Firefox. What a huge bummer.