Thank you, @ivadzy. It’s good to see a variety of approaches.
Very handy to have a file-drop example, especially to note preventDefaultOn "drop" — an interesting reference regarding this here Is call to preventDefault() really necessary on drop event?.
Didn’t think I’d need drag’n’drop but it’s a common way to load files in desktop applications so a good option to offer users.
Edit – final note before this thread closes (this is also linked by @kwindow above):
Probably the definitive set of examples is at Evan’s article Working with Files.