Throwing items in portals wont load the world

If you throw any item inside a nether/end portal, the world will not be loaded, the way i tested it was putting repeating command block by a nether portal in the nether, or by the end obsidian platform. Then i threw items inside the portal and i did not get a response from the command blocks! (the command blocks commands were: /say hi-end and /say hi-nether.

Please resolve this, because this will help automatic farms that don't require the player!