remember_me.module

<?php

/**
 * @file
 * Adds a "Remember me" checkbox to login forms.
 */

/**
 * Implements hook_init().
 */
function remember_me_init() {
  global $user;

  // If we have a user logged in, then we have a session.
  if ($user->uid) {
    // If the user chose to be remembered, recreate the session using the
    // configured session timeout.
    if (!empty($user->data['remember_me']) && variable_get('remember_me_managed', 0)) {
      _remember_me_set_lifetime(variable_get('remember_me_lifetime', 604800));
    }
  }
}

/**
 * remember_me_init() callback helper function.
 */
function _remember_me_set_lifetime($cookie_lifetime) {
  // We have session started.
  // Lets close the session, change php cookie lifetime variable, and start
  // session again.
  // Prevent sess_write from persisting the session object at this time,
  // it will happen on shutdown.
  drupal_save_session(FALSE);
  session_write_close();
  drupal_save_session(TRUE);

  // Set the cookie and session lifetime. A cookie lifetime of 0 indicates that
  // the cookie should expire when the browser is closed. The session lifetime
  // controls how long the session can live on the server without any activity.
  ini_set('session.cookie_lifetime', $cookie_lifetime);
  if ($cookie_lifetime > 0) {
    ini_set('session.gc_maxlifetime', $cookie_lifetime);
  }

  drupal_session_started(FALSE);
  drupal_session_initialize();
}

/**
 * Implements hook_user_login().
 */
function remember_me_user_login(&$edit, $account) {
  if ($account->uid) {
    $account->data['remember_me'] = !empty($edit['input']['remember_me']);

    db_update('users')
      ->fields(['data' => serialize($account->data)])
      ->condition('uid', $account->uid)
      ->execute();
  }
}

/**
 * Implements hook_form_alter().
 */
function remember_me_form_alter(&$form, $form_state, $form_id) {
  // Only make changes to these forms.
  if (in_array($form_id, array('user_login', 'user_login_block'))) {
    // Configuration for the remember me checkbox.
    $cbox['remember_me'] = array(
      '#title' => t('Remember me'),
      '#type' => variable_get('remember_me_checkbox_visible', 1) ? 'checkbox' : 'hidden',
      '#default_value' => variable_get('remember_me_checkbox', 1),
      '#attributes' => array('tabindex' => 1),
    );

    // Now lets try and insert it right after the password field in the document
    // and set the tabindex to 1 for each field so that we can jump in sequence.
    $que = array();
    foreach ($form as $key => $val) {
      switch ($key) {
        case 'name':
        case 'pass' :
          $val['#attributes']['tabindex'] = 1;
          break;
        case 'actions':
          $form = $que + $cbox + $form;
          $form[$key]['submit']['#attributes']['tabindex'] = 1;
          return;
      }
      $que[$key] = $val;
    }
  }
}

/**
 * Implements hook_theme().
 */
function remember_me_theme() {
  return array(
    'remember_me_settings_display' => array(
      'variables' => array('vars' => array()),
      'file' => 'remember_me.admin.inc',
    ),
  );
}

/**
 * Implements hook_menu().
 */
function remember_me_menu() {
  $items = array();
  $items['admin/config/system/remember_me'] = array(
    'title' => 'Remember me settings',
    'description' => 'Configure settings like session time out for remember_me module.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('remember_me_admin_settings'),
    'access arguments' => array('administer site configuration'),
    'file' => 'remember_me.admin.inc',
    'type' => MENU_NORMAL_ITEM,
  );

  return $items;
}

/**
 * Implements hook_help().
 */
function remember_me_help($path, $arg) {
  switch ($path) {
    case 'admin/help#remember_me':
      return t('Allows users to have persistent sessions via a checkbox "Remember me" on the login form.');
  }
}