<?php
// $Id: checkall.module,v 1.2.2.6 2009-03-23 17:04:32 markuspetrux Exp $

/**
 * @file
 * Extends FormAPI checkboxes with the 'checkall' behavior.
 */

/**
 * Implementation of FAPI hook_elements().
 *
 * Extend the definition of the checkboxes element, which is already
 * defined by system.module.
 *
 * @see system_elements()
 */
function checkall_elements() {
  return array(
    'checkboxes' => array(
      '#checkall' => FALSE,
      '#process' => array('checkall_element_process'),
    ),
  );
}

/**
 * Process the checkall extension for the checkboxes element.
 */
function checkall_element_process($element) {
  // See if the #checkall flag is present.
  if (!empty($element['#checkall'])) {
    $class = is_string($element['#checkall']) ? trim($element['#checkall']) : '';
    if (empty($class)) {
      $class = 'checkall-'. $element['#id'];
    }

    // Append classes to the checkboxes element.
    if (!isset($element['#attributes'])) {
      $element['#attributes'] = array();
    }
    if (empty($element['#attributes']['class'])) {
      $element['#attributes']['class'] = 'form-checkall '. $class;
    }
    else {
      $element['#attributes']['class'] .= ' form-checkall '. $class;
    }

    // Append class to the checkboxes items.
    foreach (element_children($element) as $key) {
      if ($element[$key]['#type'] == 'checkbox') {
        if (!isset($element[$key]['#attributes'])) {
          $element[$key]['#attributes'] = array();
        }
        if (empty($element[$key]['#attributes']['class'])) {
          $element[$key]['#attributes']['class'] = $class;
        }
        else {
          $element[$key]['#attributes']['class'] .= ' '. $class;
        }
      }
    }

    // Append the unique checkboxes class to Drupal.settings.checkall.
    drupal_add_js(array('checkall' => array('groups' => $class)), 'setting');

    // Add our stylesheet and javascript files to the page.
    drupal_add_css(drupal_get_path('module', 'checkall') .'/checkall.css');
    drupal_add_js(drupal_get_path('module', 'checkall') .'/checkall.js');
  }

  return $element;
}