system_settings.api.module

<?php

/**
 * @file
 *   Provide example implementations and documentation 
 *   for system_settings api capabilities.
 */

//
$setting = array(
  'name' => $name,
  'value' => $value,
  'description' => $description,
  'always_load' => $always_load,
  'modules' => array(
    'views' => array(
      'requires' => TRUE,
      'required by' => TRUE,
    ),
    'content' => array(
      'requires' => TRUE,
      'required by' => TRUE,
      'callback' => 'content_update_setting', // Not a real function (yours should be).
    ),
  ),
  'entities' => array(
    array(
      'entity' => 'node',
      'type' => 'type',
      'identifier' => 'story',
      'requires' => TRUE,
      'required by' => TRUE,
    ),
    array(
      'entity' => 'node',
      'type' => 'type',
      'identifier' => 'page',
      'requires' => TRUE,
      'required by' => FALSE,
    ),
  ),
  'groups' => array(
    'Ubercart' => array(
      'Payment',
    ),
  ),
);

/**
 * Implemenation of hook_system_settings().
 */
function hook_system_settings() {
  $settings = array();
  $settings['system_settings_handlers'] = array(
    'modules' => array('views');
    'groups' => array('system_settings');
    'setting' => array(
      'system_settings_log' => 'default',
      'system_settings_settings' => 'default',
    );
  );
  return $settings;
}

/**
 * Implementation of hook_system_settings_alter().
 */
function hook_system_settings_alter(&$settings) {
  if (isset($settings['system_settings']['handlers']['system_settings_log'])) {
    $settings['system_settings']['handlers']['system_settings_log'] = 'static_files';
  }
}

// Overriding system_settings can be done from settings.php.  This will
// override what is in code, stored in the database, and even cached.
// For now this is set as part of conf, eventually it probably replaces it.
$conf['system_settings_conf'] = array(
  'system_settings_handlers' =>array(
    'modules' => array('Garland'),
    'value' => array(
      'system_settings_log' => 'static_files',
    ),
  ),
);

/**
 * Implementation of hook_system_settings_update_handler().
 */
function hook_system_settings_update_handler() {
}

/**
 * Implementation of hook_system_settings_groups()
 */
function hook_system_settings_groups() {
  $groups = array(
    'views',
    'ubercart',
  );
  return $groups;
}