title: Firefox - document.execCommand(‘cut’/‘copy’) was denied because it was not called from inside a short running user-generated event handler
body: <p>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. </p>
  
  <p>Each component works in isolation, but when I glue them together Firefox returns the following error:</p>
  
  <blockquote>
    <p>document.execCommand(‘cut’/‘copy’) was denied because it was not
    called from inside a short running user-generated event handler</p>
  </blockquote>
  
  <p>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?</p>