Pagination automated

Extends CI's pagination class (http://codeigniter.com/user_guide/libraries/pagination.html). Just drop it in application/libraries.

EDIT: Latest version of code is in https://github.com/accent-interactive/MY_Pagination

This MY_Pagination class library is loaded automatically when you load CI's pagination lib. It sets some variables for configuration of the pagination class dynamically, depending on the URI. And it returns the pagination HTML without having to set a lot of data. This makes CI pagination a lot easier to use.

Example use (in controller):

$count = $this->db->count_all_results('my_table');
$results_per_page = 10;
$this->data['pagination'] = $this->pagination->get_pagination($count, $results_per_page);

Here's the entire library

if (! defined('BASEPATH'))
    exit('No direct script access allowed');

/**
 * Extends CI's pagination class (http://codeigniter.com/user_guide/libraries/pagination.html)
 * It sets some variables for configuration of the pagination class dynamically,
 * depending on the URI, so we don't have to substract the offset from the URI,
 * or set $config['base_url'] and $config['uri_segment'] manually in the controller
 * 
 * Here is what is set by this extension class:
 * 1. $this->offset - the current offset
 * 2. $this->uri_segment - the URI segment to be used for pagination
 * 3. $this->base_url - the base url to be used for pagination
 * (where $this refers to the pagination class)
 *
 * The way this works is simple:
 * Drop this library in folder application/libraries
 * If we use pagination, it must ALWAYS follow the following syntax and be
 * located at the END of the URI:
 * PAGINATION_SELECTOR/offset
 * E.g. http://www.example.com/controller/action/Page/2
 *
 * The PAGINATION_SELECTOR is a special string which we know will ONLY be in the
 * URI when paging is set. Let's say the PAGINATION_SELECTOR is 'Page' (since most
 * coders never use any capitals in the URI, most of the times any string with
 * a single capital character in it will suffice). The PAGINATION_SELECTOR is
 * set in the general config file,
 * in the following index: $CI->config->item('pagination_selector')
 *
 * Example use (in controller):
 * // Set pagination and get pagination HTML
 * $this->data['pagination'] = $this->pagination->get_pagination($this->db->count_all_results('my_table'), 10);
 *
 * // Retrieve paginated results, using the dynamically determined offset
 * $this->db->limit($config['per_page'], $this->pagination->offset);
 * $query = $this->db->get('my_table');
 * 
 * @name MY_Pagination.php
 * @version 1.0
 * @author Joost van Veen
 */
class MY_Pagination extends CI_Pagination
{
    
    /**
     * Pagination offset.
     * @var integer
     */
    public $offset = 0;
    
    /**
     * Opening HTML tag for pagination string 
     * @var string
     */
    public $cur_tag_open = '&nbsp;<span class="dimmed">';
    
    /**
     * Opening HTML tag for pagination string
     * @var unknown_type
     */
    public $cur_tag_close = '</span>';
    
    /**
     * Text for link to first page
     * @var string
     */
    public $first_link = 'Eerste';
    
    /**
     * Text for link to last page
     * @var string
     */
    public $last_link = 'Laatste';
    
    /**
     * Number of links to show in pagination
     * @var integer 
     */
    public $num_links = 8;
    
    /**
     * Pagination selector to be used in URI. Make sure to set this to a value 
     * that is never used elsewhere in the URI.
     * @var string
     */
    public $pagination_selector = '';

    function MY_Pagination ()
    {
        parent::CI_Pagination();
        
        $CI = & get_instance();
        
        log_message('debug', "MY custom Pagination Class Initialized");
        
        if ($CI->config->item('pagination_selector') == '') {
            show_error('config->item(\'pagination_selector\') is not set. Set config->item(\'pagination_selector\') in a config file, or $this->pagination->$this->pagination_selector');
        }
        else {
            $this->pagination_selector = $CI->config->item('pagination_selector');
        }
        
        $this->_set_pagination_offset();
    }

    /**
     * Rturn HTML for pagination, based on count ($total_rows) and limit ($per_page)
     * @param integer $total_rows
     * @param integer $per_page
     * @return string
     */
    public function get_pagination ($total_rows, $per_page)
    {
        if ($total_rows > $per_page) {
            $CI = & get_instance();
            $this->initialize(array('total_rows' => $total_rows, 'per_page' => $per_page));
            return $this->create_links();
        }
    }

    /**
     * Set dynamic pagination variables in $CI->data['pagvars']
     * @return void
     */
    private function _set_pagination_offset ()
    {
        
        // Instantiate the CI super object so we can use the uri class
        $CI = & get_instance();
        
        // Store pagination offset if it is set
        if (strstr($CI->uri->uri_string(), $this->pagination_selector)) {
            
            // Get the segment offset for the pagination selector
            $segments = $CI->uri->segment_array();
            
            // Loop through segments to retrieve pagination offset
            foreach ($segments as $key => $value) {
                
                // Find the pagination_selector and work from there
                if ($value == $this->pagination_selector) {
                    
                    // Store pagination offset
                    $this->offset = $CI->uri->segment($key + 1);
                    
                    // Store pagination segment
                    $this->uri_segment = $key + 1;
                    
                    // Set base url for paging. This only works if the
                    // pagination_selector and paging offset are AT THE END of
                    // the URI!
                    $uri = $CI->uri->uri_string();
                    $pos = strpos($uri, $this->pagination_selector);
                    $this->base_url = $CI->config->item('base_url') . substr($uri, 0, $pos + strlen($this->pagination_selector));
                }
            }
        }
        else {
            // Pagination selector was not found in URI string. So offset is 0
            $this->offset = 0;
            $this->uri_segment = 0;
            $this->base_url = $CI->config->item('base_url') . substr($CI->uri->uri_string(), 1) . '/' . $this->pagination_selector;
        }
    }
}