trying to run function just once

I use native PHP session_start() which is called in app/Controllers/BaseController.php

Once called $_SESSIONS remain active all the time a user is logged in and the session is dropped (I think when a user logs out.). Try checking to see if $_SESSION['RUNONCE'] has been set.

File:  /app/Controllers/BaseController.php

PHP Code:

//=======================================================
public function initController
(
 RequestInterface  $request, 
 ResponseInterface $response, 
 LoggerInterface  $logger
)
{
  session_start();
  $_SESSION['RUNONCE'] = $_SESSION['RUNONCE'] ?? 0;
  $_SESSION['RUNONCE'] = ++$_SESSION['RUNONCE'];

// Do Not Edit This Line
parent::initController($request, $response, $logger);
...
... 


Edit:
Just tried setting the script in index.php and it also works OK