Firefox - document.execCommand(‘cut’/‘copy’) was denied because it was not called from inside a short running user-generated event handler

Question

I am developing a single-page app, I have a button on the page, when a user clicks the button I would like to make an ajax call to my server, and then copy the returned value (via callback) to the user's clipboard.

Each component works in isolation, but when I glue them together Firefox returns the following error:

document.execCommand(‘cut’/‘copy’) was denied because it was not called from inside a short running user-generated event handler

I would like to know the specifics of this error, but there is absolutely no information online; what are the limiting conditions that trigger this error, is it a stack depth, a timeout, etc?

Answer 1

on firefox it only work with click handler, reference Interact_with_the_clipboard

Answer 2

Firefox will display the same error message if the manifest is missing the clipboardWrite permission.