public function getPerPage()
	{
		$items_per_page_list = array_keys($this->getItemsPerPageList());

		$per_page = $this->per_page ?: reset($items_per_page_list);

		if (($per_page !== 'all' && !in_array((int) $this->per_page, $items_per_page_list, true))
			|| ($per_page === 'all' && !in_array($this->per_page, $items_per_page_list, true))) {
			$per_page = reset($items_per_page_list);
		}

		return $per_page;
	}