root/trunk/system/libraries/Pagination.php

<?php defined('SYSPATH') or die('No direct script access.');
/**
 * Pagination library.
 *
 * $Id$
 *
 * @package    Core
 * @author     Kohana Team
 * @copyright  (c) 2007-2008 Kohana Team
 * @license    http://kohanaphp.com/license.html
 */
class Pagination_Core {

    // Config values
    protected $base_url       = '';
    protected $directory      = 'pagination';
    protected $style          = 'classic';
    protected $uri_segment    = 3;
    protected $query_string   = '';
    protected $items_per_page = 20;
    protected $total_items    = 0;
    protected $auto_hide      = FALSE;

    // Autogenerated values
    protected $url;
    protected $current_page;
    protected $total_pages;
    protected $current_first_item;
    protected $current_last_item;
    protected $first_page;
    protected $last_page;
    protected $previous_page;
    protected $next_page;
    protected $sql_offset;
    protected $sql_limit;

    /**
     * Constructs and returns a new Pagination object.
     *
     * @param   array   configuration settings
     * @return  object
     */
    public function factory($config = array())
    {
        return new Pagination($config);
    }

    /**
     * Constructs a new Pagination object.
     *
     * @param   array  configuration settings
     * @return  void
     */
    public function __construct($config = array())
    {
        // No custom group name given
        if ( ! isset($config['group']))
        {
            $config['group'] = 'default';
        }

        // Pagination setup
        $this->initialize($config);

        Kohana::log('debug', 'Pagination Library initialized');
    }

    /**
     * Sets config values.
     *
     * @throws  Kohana_Exception
     * @param   array  configuration settings
     * @return  void
     */
    public function initialize($config = array())
    {
        // Load config group
        if (isset($config['group']))
        {
            // Load and validate config group
            if ( ! is_array($group_config = Kohana::config('pagination.'.$config['group'])))
                throw new Kohana_Exception('pagination.undefined_group', $config['group']);

            // All pagination config groups inherit default config group
            if ($config['group'] !== 'default')
            {
                // Load and validate default config group
                if ( ! is_array($default_config = Kohana::config('pagination.default')))
                    throw new Kohana_Exception('pagination.undefined_group', 'default');

                // Merge config group with default config group
                $group_config += $default_config;
            }

            // Merge custom config items with config group
            $config += $group_config;
        }

        // Assign config values to the object
        foreach ($config as $key => $value)
        {
            if (property_exists($this, $key))
            {
                $this->$key = $value;
            }
        }

        // Clean view directory
        $this->directory = trim($this->directory, '/').'/';

        // Build generic URL with page in query string
        if ($this->query_string !== '')
        {
            // Extract current page
            $this->current_page = isset($_GET[$this->query_string]) ? (int) $_GET[$this->query_string] : 1;

            // Insert {page} placeholder
            $_GET[$this->query_string] = '{page}';

            // Create full URL
            $this->url = url::site(Router::$current_uri).'?'.str_replace('%7Bpage%7D', '{page}', http_build_query($_GET));

            // Reset page number
            $_GET[$this->query_string] = $this->current_page;
        }

        // Build generic URL with page as URI segment
        else
        {
            // Use current URI if no base_url set
            $this->url = ($this->base_url === '') ? Router::$segments : explode('/', trim($this->base_url, '/'));

            // Convert uri 'label' to corresponding integer if needed
            if (is_string($this->uri_segment))
            {
                if (($key = array_search($this->uri_segment, $this->url)) === FALSE)
                {
                    // If uri 'label' is not found, auto add it to base_url
                    $this->url[] = $this->uri_segment;
                    $this->uri_segment = count($this->url) + 1;
                }
                else
                {
                    $this->uri_segment = $key + 2;
                }
            }

            // Insert {page} placeholder
            $this->url[$this->uri_segment - 1] = '{page}';

            // Create full URL
            $this->url = url::site(implode('/', $this->url)).Router::$query_string;

            // Extract current page
            $this->current_page = URI::instance()->segment($this->uri_segment);
        }

        // Core pagination values
        $this->total_items        = (int) max(0, $this->total_items);
        $this->items_per_page     = (int) max(1, $this->items_per_page);
        $this->total_pages        = (int) ceil($this->total_items / $this->items_per_page);
        $this->current_page       = (int) min(max(1, $this->current_page), max(1, $this->total_pages));
        $this->current_first_item = (int) min((($this->current_page - 1) * $this->items_per_page) + 1, $this->total_items);
        $this->current_last_item  = (int) min($this->current_first_item + $this->items_per_page - 1, $this->total_items);

        // If there is no first/last/previous/next page, relative to the
        // current page, value is set to FALSE. Valid page number otherwise.
        $this->first_page         = ($this->current_page === 1) ? FALSE : 1;
        $this->last_page          = ($this->current_page >= $this->total_pages) ? FALSE : $this->total_pages;
        $this->previous_page      = ($this->current_page > 1) ? $this->current_page - 1 : FALSE;
        $this->next_page          = ($this->current_page < $this->total_pages) ? $this->current_page + 1 : FALSE;

        // SQL values
        $this->sql_offset         = (int) ($this->current_page - 1) * $this->items_per_page;
        $this->sql_limit          = sprintf(' LIMIT %d OFFSET %d ', $this->items_per_page, $this->sql_offset);
    }

    /**
     * Generates the HTML for the chosen pagination style.
     *
     * @param   string  pagination style
     * @return  string  pagination html
     */
    public function render($style = NULL)
    {
        // Hide single page pagination
        if ($this->auto_hide === TRUE AND $this->total_pages <= 1)
            return '';

        if ($style === NULL)
        {
            // Use default style
            $style = $this->style;
        }

        // Return rendered pagination view
        return View::factory($this->directory.$style, get_object_vars($this))->render();
    }

    /**
     * Magically converts Pagination object to string.
     *
     * @return  string  pagination html
     */
    public function __toString()
    {
        return $this->render();
    }

    /**
     * Magically gets a pagination variable.
     *
     * @param   string  variable key
     * @return  mixed   variable value if the key is found
     * @return  void    if the key is not found
     */
    public function __get($key)
    {
        if (isset($this->$key))
            return $this->$key;
    }

    /**
     * Adds a secondary interface for accessing properties, e.g. $pagination->total_pages().
     * Note that $pagination->total_pages is the recommended way to access properties.
     *
     * @param   string  function name
     * @return  string
     */
    public function __call($func, $args = NULL)
    {
        return $this->__get($func);
    }

} // End Pagination Class