1334653 - document.execCommand denied from background

Status: RESOLVED DUPLICATE of bug 1197451

(WebExtensions :: Untriaged, defect)

Description

[Ian Bicking (:ianbicking)]

I have this code running in a background WebExtension page (this works in Chrome):

  let el = document.createElement("textarea");
  document.body.appendChild(el);
  el.value = text;
  el.select();
  document.execCommand("copy");
  document.body.removeChild(el);

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

Version: 52.0a2 (2017-01-23) (64-bit)