print-during-event.sub.html (311B)
1 <!DOCTYPE html> 2 <meta charset="utf-8"> 3 <title>Page that tries to print during an event</title> 4 5 <script> 6 "use strict"; 7 8 window.on{{GET[event]}} = () => { 9 try { 10 window.print(); 11 } catch (e) { 12 window.opener.postMessage(`error: ${e.message}`); 13 } 14 }; 15 16 window.opener.postMessage("start", "*"); 17 </script>