<?php

// $Id: pager.inc,v 1.63.2.1 2009/07/01 20:51:55 goba Exp $

/**

 * @file

 * Functions to aid in presenting database results as a set of pages.

 */

/**

 * Perform a paged database query.

 *

 * Use this function when doing select queries you wish to be able to page. The

 * pager uses LIMIT-based queries to fetch only the records required to render a

 * certain page. However, it has to learn the total number of records returned

 * by the query to compute the number of pages (the number of records / records

 * per page). This is done by inserting "COUNT(*)" in the original query. For

 * example, the query "SELECT nid, type FROM node WHERE status = '1' ORDER BY

 * sticky DESC, created DESC" would be rewritten to read "SELECT COUNT(*) FROM

 * node WHERE status = '1' ORDER BY sticky DESC, created DESC". Rewriting the

 * query is accomplished using a regular expression.

 *

 * Unfortunately, the rewrite rule does not always work as intended for queries

 * that already have a "COUNT(*)" or a "GROUP BY" clause, and possibly for

 * other complex queries. In those cases, you can optionally pass a query that

 * will be used to count the records.

 *

 * For example, if you want to page the query "SELECT COUNT(*), TYPE FROM node

 * GROUP BY TYPE", pager_query() would invoke the incorrect query "SELECT

 * COUNT(*) FROM node GROUP BY TYPE". So instead, you should pass "SELECT

 * COUNT(DISTINCT(TYPE)) FROM node" as the optional $count_query parameter.

 *

 * @param $query

 *   The SQL query that needs paging.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $count_query

 *   An SQL query used to count matching records.

 * @param ...

 *   A variable number of arguments which are substituted into the query (and

 *   the count query) using printf() syntax. Instead of a variable number of

 *   query arguments, you may also pass a single array containing the query

 *   arguments.

 * @return

 *   A database query result resource, or FALSE if the query was not executed

 *   correctly.

 *

 * @ingroup database

 */

function pager_query($query, $limit = 10, $element = 0, $count_query = NULL) {

  global $pager_page_array, $pager_total, $pager_total_items;

  $page = isset($_GET['page']) ? $_GET['page'] : '';

  // Substitute in query arguments.

  $args = func_get_args();

  $args = array_slice($args, 4);

  // Alternative syntax for '...'

  if (isset($args[0]) && is_array($args[0])) {

    $args = $args[0];

  }

  // Construct a count query if none was given.

  if (!isset($count_query)) {

    $count_query = preg_replace(array('/SELECT.*?FROM /As', '/ORDER BY .*/'), array('SELECT COUNT(*) FROM ', ''), $query);

  }

  // Convert comma-separated $page to an array, used by other functions.

  $pager_page_array = explode(',', $page);

  // We calculate the total of pages as ceil(items / limit).

  $pager_total_items[$element] = db_result(db_query($count_query, $args));

  $pager_total[$element] = ceil($pager_total_items[$element] / $limit);

  $pager_page_array[$element] = max(0, min((int)$pager_page_array[$element], ((int)$pager_total[$element]) - 1));

  return db_query_range($query, $args, $pager_page_array[$element] * $limit, $limit);

}

/**

 * Compose a query string to append to pager requests.

 *

 * @return

 *   A query string that consists of all components of the current page request

 *   except for those pertaining to paging.

 */

function pager_get_querystring() {

  static $string = NULL;

  if (!isset($string)) {

    $string = drupal_query_string_encode($_REQUEST, array_merge(array('q', 'page', 'pass'), array_keys($_COOKIE)));

  }

  return $string;

}

/**

 * Format a query pager.

 *

 * Menu callbacks that display paged query results should call theme('pager') to

 * retrieve a pager control so that users can view other results.

 * Format a list of nearby pages with additional query results.

 *

 * @param $tags

 *   An array of labels for the controls in the pager.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager links.

 * @param $quantity

 *   The number of pages in the list.

 * @return

 *   An HTML string that generates the query pager.

 *

 * @ingroup themeable

 */

function theme_pager($tags = array(), $limit = 10, $element = 0, $parameters = array(), $quantity = 9) {

  global $pager_page_array, $pager_total;

  // Calculate various markers within this pager piece:

  // Middle is used to "center" pages around the current page.

  $pager_middle = ceil($quantity / 2);

  // current is the page we are currently paged to

  $pager_current = $pager_page_array[$element] + 1;

  // first is the first page listed by this pager piece (re quantity)

  $pager_first = $pager_current - $pager_middle + 1;

  // last is the last page listed by this pager piece (re quantity)

  $pager_last = $pager_current + $quantity - $pager_middle;

  // max is the maximum page number

  $pager_max = $pager_total[$element];

  // End of marker calculations.

  // Prepare for generation loop.

  $i = $pager_first;

  if ($pager_last > $pager_max) {

    // Adjust "center" if at end of query.

    $i = $i + ($pager_max - $pager_last);

    $pager_last = $pager_max;

  }

  if ($i <= 0) {

    // Adjust "center" if at start of query.

    $pager_last = $pager_last + (1 - $i);

    $i = 1;

  }

  // End of generation loop preparation.

  $li_first = theme('pager_first', (isset($tags[0]) ? $tags[0] : t('« first')), $limit, $element, $parameters);

  $li_previous = theme('pager_previous', (isset($tags[1]) ? $tags[1] : t('‹ previous')), $limit, $element, 1, $parameters);

  $li_next = theme('pager_next', (isset($tags[3]) ? $tags[3] : t('next ›')), $limit, $element, 1, $parameters);

  $li_last = theme('pager_last', (isset($tags[4]) ? $tags[4] : t('last »')), $limit, $element, $parameters);

  if ($pager_total[$element] > 1) {

    if ($li_first) {

      $items[] = array(

        'class' => 'pager-first',

        'data' => $li_first,

      );

    }

    if ($li_previous) {

      $items[] = array(

        'class' => 'pager-previous',

        'data' => $li_previous,

      );

    }

    // When there is more than one page, create the pager list.

    if ($i != $pager_max) {

      if ($i > 1) {

        $items[] = array(

          'class' => 'pager-ellipsis',

          'data' => '…',

        );

      }

      // Now generate the actual pager piece.

      for (; $i <= $pager_last && $i <= $pager_max; $i++) {

        if ($i < $pager_current) {

          $items[] = array(

            'class' => 'pager-item',

            'data' => theme('pager_previous', $i, $limit, $element, ($pager_current - $i), $parameters),

          );

        }

        if ($i == $pager_current) {

          $items[] = array(

            'class' => 'pager-current',

            'data' => $i,

          );

        }

        if ($i > $pager_current) {

          $items[] = array(

            'class' => 'pager-item',

            'data' => theme('pager_next', $i, $limit, $element, ($i - $pager_current), $parameters),

          );

        }

      }

      if ($i < $pager_max) {

        $items[] = array(

          'class' => 'pager-ellipsis',

          'data' => '…',

        );

      }

    }

    // End generation.

    if ($li_next) {

      $items[] = array(

        'class' => 'pager-next',

        'data' => $li_next,

      );

    }

    if ($li_last) {

      $items[] = array(

        'class' => 'pager-last',

        'data' => $li_last,

      );

    }

    return theme('item_list', $items, NULL, 'ul', array('class' => 'pager'));

  }

}

/**

 * @name Pager pieces

 * @{

 * Use these pieces to construct your own custom pagers in your theme. Note that

 * you should NOT modify this file to customize your pager.

 */

/**

 * Format a "first page" link.

 *

 * @param $text

 *   The name (or image) of the link.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager links.

 * @return

 *   An HTML string that generates this piece of the query pager.

 *

 * @ingroup themeable

 */

function theme_pager_first($text, $limit, $element = 0, $parameters = array()) {

  global $pager_page_array;

  $output = '';

  // If we are anywhere but the first page

  if ($pager_page_array[$element] > 0) {

    $output = theme('pager_link', $text, pager_load_array(0, $element, $pager_page_array), $element, $parameters);

  }

  return $output;

}

/**

 * Format a "previous page" link.

 *

 * @param $text

 *   The name (or image) of the link.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $interval

 *   The number of pages to move backward when the link is clicked.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager links.

 * @return

 *   An HTML string that generates this piece of the query pager.

 *

 * @ingroup themeable

 */

function theme_pager_previous($text, $limit, $element = 0, $interval = 1, $parameters = array()) {

  global $pager_page_array;

  $output = '';

  // If we are anywhere but the first page

  if ($pager_page_array[$element] > 0) {

    $page_new = pager_load_array($pager_page_array[$element] - $interval, $element, $pager_page_array);

    // If the previous page is the first page, mark the link as such.

    if ($page_new[$element] == 0) {

      $output = theme('pager_first', $text, $limit, $element, $parameters);

    }

    // The previous page is not the first page.

    else {

      $output = theme('pager_link', $text, $page_new, $element, $parameters);

    }

  }

  return $output;

}

/**

 * Format a "next page" link.

 *

 * @param $text

 *   The name (or image) of the link.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $interval

 *   The number of pages to move forward when the link is clicked.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager links.

 * @return

 *   An HTML string that generates this piece of the query pager.

 *

 * @ingroup themeable

 */

function theme_pager_next($text, $limit, $element = 0, $interval = 1, $parameters = array()) {

  global $pager_page_array, $pager_total;

  $output = '';

  // If we are anywhere but the last page

  if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {

    $page_new = pager_load_array($pager_page_array[$element] + $interval, $element, $pager_page_array);

    // If the next page is the last page, mark the link as such.

    if ($page_new[$element] == ($pager_total[$element] - 1)) {

      $output = theme('pager_last', $text, $limit, $element, $parameters);

    }

    // The next page is not the last page.

    else {

      $output = theme('pager_link', $text, $page_new, $element, $parameters);

    }

  }

  return $output;

}

/**

 * Format a "last page" link.

 *

 * @param $text

 *   The name (or image) of the link.

 * @param $limit

 *   The number of query results to display per page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager links.

 * @return

 *   An HTML string that generates this piece of the query pager.

 *

 * @ingroup themeable

 */

function theme_pager_last($text, $limit, $element = 0, $parameters = array()) {

  global $pager_page_array, $pager_total;

  $output = '';

  // If we are anywhere but the last page

  if ($pager_page_array[$element] < ($pager_total[$element] - 1)) {

    $output = theme('pager_link', $text, pager_load_array($pager_total[$element] - 1, $element, $pager_page_array), $element, $parameters);

  }

  return $output;

}

/**

 * Format a link to a specific query result page.

 *

 * @param $page_new

 *   The first result to display on the linked page.

 * @param $element

 *   An optional integer to distinguish between multiple pagers on one page.

 * @param $parameters

 *   An associative array of query string parameters to append to the pager link.

 * @param $attributes

 *   An associative array of HTML attributes to apply to a pager anchor tag.

 * @return

 *   An HTML string that generates the link.

 *

 * @ingroup themeable

 */

function theme_pager_link($text, $page_new, $element, $parameters = array(), $attributes = array()) {

  $page = isset($_GET['page']) ? $_GET['page'] : '';

  if ($new_page = implode(',', pager_load_array($page_new[$element], $element, explode(',', $page)))) {

    $parameters['page'] = $new_page;

  }

  $query = array();

  if (count($parameters)) {

    $query[] = drupal_query_string_encode($parameters, array());

  }

  $querystring = pager_get_querystring();

  if ($querystring != '') {

    $query[] = $querystring;

  }

  // Set each pager link title

  if (!isset($attributes['title'])) {

    static $titles = NULL;

    if (!isset($titles)) {

      $titles = array(

        t('« first') => t('Go to first page'),

        t('‹ previous') => t('Go to previous page'),

        t('next ›') => t('Go to next page'),

        t('last »') => t('Go to last page'),

      );

    }

    if (isset($titles[$text])) {

      $attributes['title'] = $titles[$text];

    }

    else if (is_numeric($text)) {

      $attributes['title'] = t('Go to page @number', array('@number' => $text));

    }

  }

  return l($text, $_GET['q'], array('attributes' => $attributes, 'query' => count($query) ? implode('&', $query) : NULL));

}

/**

 * @} End of "Pager pieces".

 */

/**

 * Helper function

 *

 * Copies $old_array to $new_array and sets $new_array[$element] = $value

 * Fills in $new_array[0 .. $element - 1] = 0

 */

function pager_load_array($value, $element, $old_array) {

  $new_array = $old_array;

  // Look for empty elements.

  for ($i = 0; $i < $element; $i++) {