creating back page links in Codeigniter

Question

I have a page with URL http://arslan/admin/category/index/0/name/asc/10 in Codeigniter. In this URL, the uri_segment start from 0. This (0

Answer 1

I extend the session class by creating /application/libaries/MY_Session.php

class MY_Session extends CI_Session {

    function __construct() {
        parent::__construct();

        $this->tracker();
    }

    function tracker() {
        $this->CI->load->helper('url');

        $tracker =& $this->userdata('_tracker');

        if( !IS_AJAX ) {
            $tracker[] = array(
                'uri'   =>      $this->CI->uri->uri_string(),
                'ruri'  =>      $this->CI->uri->ruri_string(),
                'timestamp' =>  time()
            );
        }

        $this->set_userdata( '_tracker', $tracker );
    }


    function last_page( $offset = 0, $key = 'uri' ) {   
        if( !( $history = $this->userdata('_tracker') ) ) {
            return $this->config->item('base_url');
        }

        $history = array_reverse($history); 

        if( isset( $history[$offset][$key] ) ) {
            return $history[$offset][$key];
        } else {
            return $this->config->item('base_url');
        }
    }
}

And then to retrieve the URL of the last page visited you call

$this->session->last_page();

And you can increase the offset and type of information returned etc too

$this->session->last_page(1); // page before last
$this->session->last_page(2); // 3 pages ago

The function doesn't add pages called using Ajax to the tracker but you can easily remove the if( !IS_AJAX ) bit to make it do so.

Edit: If you run to the error Undefined constant IS_AJAX, assumed IS_AJAX add the line below to /application/config/constants.php

define('IS_AJAX', isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest');