protected function getObjectRequestedById(string $class) {
	
		// reads from url requested item id
		$itemId = Router::get(0);
		
		if (!$itemId) {
			$this->enqueueError($this->lang('NO_ID_OF_ITEM_TO_EDIT', $class));
			return NULL;
		}
		
		$object = new $class($itemId);
	
		if ($object->isLoaded()) {
				
			return $object;
	
		} else {
	
			$this->enqueueError($this->lang('ID_OF_ITEM_TO_EDIT_IS_NOT_VALID', $class));
			$this->logError('Object ' . $class . ' id=' . $itemId . ' has not been loaded');
			return NULL;
	
		}
	
	}