<?php

/**
 * @file
 * This is an example describing how a module can implement a pager in order
 * to reduce the number of output rows to the screen and allow a user
 * to scroll through multiple screens of output.
 *
 * See:
 * @link http://drupal.org/developing/api/database Database API @endlink
 * @link http://drupal.org/node/508796 Extenders @endlink
 */

/**
 * @defgroup pager_example Example: Pager
 * @ingroup examples
 * @{
 * Example of a results pager.
 */

/**
 * Implements hook_help().
 */
function pager_example_help($path, $arg) {
  switch ($path) {
    case 'examples/pager_example':
      return '<p>' . t('The layout here is a themed as a table with a default limit of 10 rows per page. The limit can be changed in the code by changing the limit to some other value.  This can be extended to add a filter form as well so the user can choose how many they would like to see on each screen.') . '</p>';
  }
}

/**
 * Implements hook_menu().
 */
function pager_example_menu() {
  $items['examples/pager_example'] = array(
    'title' => 'Pager example',
    'description' => 'Show a page with a long list across multiple pages',
    'page callback' => 'pager_example_page',
    'access callback' => TRUE,
  );
  return $items;
}

/**
 * Build the pager query.
 *
 * Uses the date_formats table since it is installed with ~35 rows
 * in it and we don't have to create fake data in order to show
 * this example.
 *
 * @return array
 *   A render array completely set up with a pager.
 */
function pager_example_page() {
  // We are going to output the results in a table with a nice header.
  $header = array(
    array('data' => t('DFID')),
    array('data' => t('Format')),
    array('data' => t('Type')),
  );

  // We are extending the PagerDefault class here.
  // It has a default of 10 rows per page.
  // The extend('PagerDefault') part here does all the magic.
  $query = db_select('date_formats', 'd')->extend('PagerDefault');
  $query->fields('d', array('dfid', 'format', 'type'));

  // Change the number of rows with the limit() call.
  $result = $query
    ->limit(10)
    ->orderBy('d.dfid')
    ->execute();

  $rows = array();
  foreach ($result as $row) {
    // Normally we would add some nice formatting to our rows
    // but for our purpose we are simply going to add our row
    // to the array.
    $rows[] = array('data' => (array) $row);
  }

  // Create a render array ($build) which will be themed as a table with a
  // pager.
  $build['pager_table'] = array(
    '#theme' => 'table',
    '#header' => $header,
    '#rows' => $rows,
    '#empty' => t('There are no date formats found in the db'),
  );

  // Attach the pager theme.
  $build['pager_pager'] = array('#theme' => 'pager');

  return $build;
}
/**
 * @} End of "defgroup pager_example".
 */
