CodeIgniter table pagination

pagination.php

<?php
	$order_by = ''; // URL segment 2
	$sort = 'desc'; // URL segment 3
	$page = '1'; // URL segment 4
	$data_total = ''; // Total number of entries
	$number_of_rows = 10; // Number of table rows per page
	$page_limit = 10; // Max pages shown in pagination at a time

	if($this->uri->segment(2)){
		$order_by = $this->uri->segment(2);
	}
	if($this->uri->segment(3)){
		$sort = $this->uri->segment(3);
	}
	if($this->uri->segment(4)){
		$page = $this->uri->segment(4);
	}

	$pages_count = ceil( $data_total/$number_of_rows );

	if($page > 1){
		$prev_page = $page-1;
		$prev_disable = '';
	}else{
		$prev_page = $page;
		$prev_disable = 'disable';
	}
	if(count($feels) == $number_of_rows){
		$next_page = $page+1;
		$next_disable = '';
	}else{
		$next_page = $page;
		$next_disable = 'disable';
	}
?>
<div class="nav_container">
	<a class="<?= $prev_disable ?> btn_nav" href="<?= site_url('controller/'.$order_by.'/'.$sort.'/'.$prev_page) ?>">PREV</a>
	<?php
		if($page >= ceil($page_limit/2)){
			$start = $page-ceil($page_limit/2-1);
		}else{
			$start = 1;
		}
		if($pages_count < $page_limit){
			$pages_displayed = $pages_count;
		}else{
			$pages_displayed = $page_limit+$start-1;
			if($pages_displayed >= $pages_count){
				$start = $pages_count-$page_limit+1;
				$pages_displayed = $pages_count;
			}
		}
		if($pages_count == $page){
			$next_disable = 'disable';
			$next_page = $page;
		}
		if($start > 1){
			echo '<a class="btn_nav" href="'.site_url('controller'.$order_by.'/'.$sort.'/'.($start-1)).'">&hellip;</a>';
		}
		for ($i=$start; $i <= $pages_displayed; $i++) { 
			echo '<a class="btn_nav '. (($page == $i)? "disable":"") .'" href="'.site_url('controller'.$order_by.'/'.$sort.'/'.$i).'">'.$i.'</a>';
		}
		if($pages_count > $pages_displayed){
			echo '<a class="btn_nav" href="'.site_url('controller/'.$order_by.'/'.$sort.'/'.($pages_displayed+1)).'">&hellip;</a>';
		}
	?>
	<a class="<?= $next_disable ?> btn_nav" href="<?= site_url('controller/'.$order_by.'/'.$sort.'/'.$next_page) ?>">NEXT</a>
</div>