user.module

<?php
// $Id$

/**
 * @file
 * Enables the user registration and login system.
 */

/**
 * Maximum length of username text field.
 */
define('USERNAME_MAX_LENGTH', 60);

/**
 * Maximum length of user e-mail text field.
 */
define('EMAIL_MAX_LENGTH', 64);

/**
 * Invokes hook_user() in every module.
 *
 * We cannot use module_invoke() for this, because the arguments need to
 * be passed by reference.
 */
function user_module_invoke($type, &$array, &$user, $category = NULL) {
  foreach (module_list() as $module) {
    $function = $module . '_user';
    if (function_exists($function)) {
      $function($type, $array, $user, $category);
    }
  }
}

/**
 * Implementation of hook_theme().
 */
function user_theme() {
  return array(
    'user_picture' => array(
      'arguments' => array('account' => NULL),
      'template' => 'user-picture',
    ),
    'user_profile' => array(
      'arguments' => array('account' => NULL),
      'template' => 'user-profile',
      'file' => 'user.pages.inc',
    ),
    'user_profile_category' => array(
      'arguments' => array('element' => NULL),
      'template' => 'user-profile-category',
      'file' => 'user.pages.inc',
    ),
    'user_profile_item' => array(
      'arguments' => array('element' => NULL),
      'template' => 'user-profile-item',
      'file' => 'user.pages.inc',
    ),
    'user_list' => array(
      'arguments' => array('users' => NULL, 'title' => NULL),
    ),
    'user_admin_perm' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    'user_admin_new_role' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    'user_admin_account' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    'user_filter_form' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    'user_filters' => array(
      'arguments' => array('form' => NULL),
      'file' => 'user.admin.inc',
    ),
    'user_signature' => array(
      'arguments' => array('signature' => NULL),
    ),
  );
}

function user_external_load($authname) {
  $result = db_query("SELECT uid FROM {authmap} WHERE authname = '%s'", $authname);

  if ($user = db_fetch_array($result)) {
    return user_load($user);
  }
  else {
    return FALSE;
  }
}

/**
 * Perform standard Drupal login operations for a user object.
 *
 * The user object must already be authenticated. This function verifies
 * that the user account is not blocked and then performs the login,
 * updates the login timestamp in the database, invokes hook_user('login'),
 * and regenerates the session.
 *
 * @param $account
 *    An authenticated user object to be set as the currently logged
 *    in user.
 * @param $edit
 *    The array of form values submitted by the user, if any.
 *    This array is passed to hook_user op login.
 * @return boolean
 *    TRUE if the login succeeds, FALSE otherwise.
 */
function user_external_login($account, $edit = array()) {
  $form = drupal_get_form('user_login');

  $state['values'] = $edit;
  if (empty($state['values']['name'])) {
    $state['values']['name'] = $account->name;
  }

  // Check if user is blocked.
  user_login_name_validate($form, $state, (array)$account);
  if (form_get_errors()) {
    // Invalid login.
    return FALSE;
  }

  // Valid login.
  global $user;
  $user = $account;
  user_authenticate_finalize($state['values']);
  return TRUE;
}

/**
 * Fetch a user object.
 *
 * @param $array
 *   An associative array of attributes to search for in selecting the
 *   user, such as user name or e-mail address.
 *
 * @return
 *   A fully-loaded $user object upon successful user load or FALSE if user
 *   cannot be loaded.
 */
function user_load($array = array()) {
  // Dynamically compose a SQL query:
  $query = array();
  $params = array();

  if (is_numeric($array)) {
    $array = array('uid' => $array);
  }
  elseif (!is_array($array)) {
    return FALSE;
  }

  foreach ($array as $key => $value) {
    if ($key == 'uid' || $key == 'status') {
      $query[] = "$key = %d";
      $params[] = $value;
    }
    else if ($key == 'pass') {
      $query[] = "pass = '%s'";
      $params[] = $value;
    }
    else {
      $query[]= "LOWER($key) = LOWER('%s')";
      $params[] = $value;
    }
  }
  $result = db_query('SELECT * FROM {users} u WHERE ' . implode(' AND ', $query), $params);

  if ($user = db_fetch_object($result)) {
    $user = drupal_unpack($user);

    $user->roles = array();
    if ($user->uid) {
      $user->roles[DRUPAL_AUTHENTICATED_RID] = 'authenticated user';
    }
    else {
      $user->roles[DRUPAL_ANONYMOUS_RID] = 'anonymous user';
    }
    $result = db_query('SELECT r.rid, r.name FROM {role} r INNER JOIN {users_roles} ur ON ur.rid = r.rid WHERE ur.uid = %d', $user->uid);
    while ($role = db_fetch_object($result)) {
      $user->roles[$role->rid] = $role->name;
    }
    user_module_invoke('load', $array, $user);
  }
  else {
    $user = FALSE;
  }

  return $user;
}

/**
 * Save changes to a user account or add a new user.
 *
 * @param $account
 *   The $user object for the user to modify or add. If $user->uid is
 *   omitted, a new user will be added.
 *
 * @param $edit
 *   An array of fields and values to save. For example array('name'
 *   => 'My name').  Keys that do not belong to columns in the user-related
 *   tables are added to the a serialized array in the 'data' column
 *   and will be loaded in the $user->data array by user_load().
 *   Setting a field to NULL deletes it from the data column.
 *
 * @param $category
 *   (optional) The category for storing profile information in.
 *
 * @return
 *   A fully-loaded $user object upon successful save or FALSE if the save failed.
 */
function user_save($account, $edit = array(), $category = 'account') {
  $table = drupal_get_schema('users');
  $user_fields = $table['fields'];

  if (!empty($edit['pass'])) {
    // Allow alternate password hashing schemes.
    require_once DRUPAL_ROOT . '/' . variable_get('password_inc', 'includes/password.inc');
    $edit['pass'] = user_hash_password(trim($edit['pass']));
    // Abort if the hashing failed and returned FALSE.
    if (!$edit['pass']) {
      return FALSE;
    }
  }
  else {
    // Avoid overwriting an existing password with a blank password.
    unset($edit['pass']);
  }

  if (is_object($account) && $account->uid) {
    user_module_invoke('update', $edit, $account, $category);
    $data = unserialize(db_result(db_query('SELECT data FROM {users} WHERE uid = %d', $account->uid)));
    // Consider users edited by an administrator as logged in, if they haven't
    // already, so anonymous users can view the profile (if allowed).
    if (empty($edit['access']) && empty($account->access) && user_access('administer users')) {
      $edit['access'] = REQUEST_TIME;
    }
    foreach ($edit as $key => $value) {
      // Fields that don't pertain to the users or user_roles
      // automatically serialized into the users.data column.
      if ($key != 'roles' && empty($user_fields[$key])) {
        if ($value === NULL) {
          unset($data[$key]);
        }
        else {
          $data[$key] = $value;
        }
      }
    }

    $edit['data'] = $data;
    $edit['uid'] = $account->uid;
    // Save changes to the users table.
    $success = drupal_write_record('users', $edit, 'uid');
    if (!$success) {
      // The query failed - better to abort the save than risk further data loss.
      return FALSE;
    }

    // Reload user roles if provided.
    if (isset($edit['roles']) && is_array($edit['roles'])) {
      db_query('DELETE FROM {users_roles} WHERE uid = %d', $account->uid);

      foreach (array_keys($edit['roles']) as $rid) {
        if (!in_array($rid, array(DRUPAL_ANONYMOUS_RID, DRUPAL_AUTHENTICATED_RID))) {
          db_query('INSERT INTO {users_roles} (uid, rid) VALUES (%d, %d)', $account->uid, $rid);
        }
      }
    }

    // Delete a blocked user's sessions to kick them if they are online.
    if (isset($edit['status']) && $edit['status'] == 0) {
      drupal_session_destroy_uid($account->uid);
    }

    // If the password changed, delete all open sessions and recreate
    // the current one.
    if (!empty($edit['pass'])) {
      drupal_session_destroy_uid($account->uid);
      drupal_session_regenerate();
    }

    // Refresh user object.
    $user = user_load(array('uid' => $account->uid));

    // Send emails after we have the new user object.
    if (isset($edit['status']) && $edit['status'] != $account->status) {
      // The user's status is changing; conditionally send notification email.
      $op = $edit['status'] == 1 ? 'status_activated' : 'status_blocked';
      _user_mail_notify($op, $user);
    }

    user_module_invoke('after_update', $edit, $user, $category);
  }
  else {
    // Allow 'created' to be set by the caller.
    if (!isset($edit['created'])) {
      $edit['created'] = REQUEST_TIME;
    }
    // Consider users created by an administrator as already logged in, so
    // anonymous users can view the profile (if allowed).
    if (empty($edit['access']) && user_access('administer users')) {
      $edit['access'] = REQUEST_TIME;
    }

    $success = drupal_write_record('users', $edit);
    if (!$success) {
      // On a failed INSERT some other existing user's uid may be returned.
      // We must abort to avoid overwriting their account.
      return FALSE;
    }

    // Build the initial user object.
    $user = user_load(array('uid' => $edit['uid']));

    user_module_invoke('insert', $edit, $user, $category);

    // Note, we wait with saving the data column to prevent module-handled
    // fields from being saved there.
    $data = array();
    foreach ($edit as $key => $value) {
      if (($key != 'roles') && (empty($user_fields[$key])) && ($value !== NULL)) {
        $data[$key] = $value;
      }
    }
    if (!empty($data)) {
      $data_array = array('uid' => $user->uid, 'data' => $data);
      drupal_write_record('users', $data_array, 'uid');
    }

    // Save user roles (delete just to be safe).
    if (isset($edit['roles']) && is_array($edit['roles'])) {
      db_query('DELETE FROM {users_roles} WHERE uid = %d', $edit['uid']);
      foreach (array_keys($edit['roles']) as $rid) {
        if (!in_array($rid, array(DRUPAL_ANONYMOUS_RID, DRUPAL_AUTHENTICATED_RID))) {
          db_query('INSERT INTO {users_roles} (uid, rid) VALUES (%d, %d)', $edit['uid'], $rid);
        }
      }
    }

    // Build the finished user object.
    $user = user_load(array('uid' => $edit['uid']));
  }

  return $user;
}

/**
 * Verify the syntax of the given name.
 */
function user_validate_name($name) {
  if (!$name) {
    return t('You must enter a username.');
  }
  if (substr($name, 0, 1) == ' ') {
    return t('The username cannot begin with a space.');
  }
  if (substr($name, -1) == ' ') {
    return t('The username cannot end with a space.');
  }
  if (strpos($name, '  ') !== FALSE) {
    return t('The username cannot contain multiple spaces in a row.');
  }
  if (preg_match('/[^\x{80}-\x{F7} a-z0-9@_.\'-]/i', $name)) {
    return t('The username contains an illegal character.');
  }
  if (preg_match('/[\x{80}-\x{A0}' .         // Non-printable ISO-8859-1 + NBSP
                   '\x{AD}' .                // Soft-hyphen
                   '\x{2000}-\x{200F}' .     // Various space characters
                   '\x{2028}-\x{202F}' .     // Bidirectional text overrides
                   '\x{205F}-\x{206F}' .     // Various text hinting characters
                   '\x{FEFF}' .              // Byte order mark
                   '\x{FF01}-\x{FF60}' .     // Full-width latin
                   '\x{FFF9}-\x{FFFD}' .     // Replacement characters
                   '\x{0}-\x{1F}]/u',        // NULL byte and control characters
                   $name)) {
    return t('The username contains an illegal character.');
  }
  if (drupal_strlen($name) > USERNAME_MAX_LENGTH) {
    return t('The username %name is too long: it must be %max characters or less.', array('%name' => $name, '%max' => USERNAME_MAX_LENGTH));
  }
}

function user_validate_mail($mail) {
  if (!$mail) {
    return t('You must enter an e-mail address.');
  }
  if (!valid_email_address($mail)) {
    return t('The e-mail address %mail is not valid.', array('%mail' => $mail));
  }
}

function user_validate_picture(&$form, &$form_state) {
  // If required, validate the uploaded picture.
  $validators = array(
    'file_validate_is_image' => array(),
    'file_validate_image_resolution' => array(variable_get('user_picture_dimensions', '85x85')),
    'file_validate_size' => array(variable_get('user_picture_file_size', '30') * 1024),
  );
  if ($file = file_save_upload('picture_upload', $validators)) {
    // Remove the old picture.
    if (isset($form_state['values']['_account']->picture) && file_exists($form_state['values']['_account']->picture)) {
      file_delete($form_state['values']['_account']->picture);
    }

    // The image was saved using file_save_upload() and was added to the
    // files table as a temporary file. We'll make a copy and let the garbage
    // collector delete the original upload.
    $info = image_get_info($file->filepath);
    $destination = file_create_path(variable_get('user_picture_path', 'pictures') . '/picture-' . $form['#uid'] . '.' . $info['extension']);
    if ($filepath = file_copy($file->filepath, $destination, FILE_EXISTS_REPLACE)) {
      $form_state['values']['picture'] = $filepath;
    }
    else {
      form_set_error('picture_upload', t("Failed to upload the picture image; the %directory directory doesn't exist or is not writable.", array('%directory' => variable_get('user_picture_path', 'pictures'))));
    }
  }
}

/**
 * Generate a random alphanumeric password.
 */
function user_password($length = 10) {
  // This variable contains the list of allowable characters for the
  // password. Note that the number 0 and the letter 'O' have been
  // removed to avoid confusion between the two. The same is true
  // of 'I', 1, and 'l'.
  $allowable_characters = 'abcdefghijkmnopqrstuvwxyzABCDEFGHJKLMNPQRSTUVWXYZ23456789';

  // Zero-based count of characters in the allowable list:
  $len = strlen($allowable_characters) - 1;

  // Declare the password as a blank string.
  $pass = '';

  // Loop the number of times specified by $length.
  for ($i = 0; $i < $length; $i++) {

    // Each iteration, pick a random character from the
    // allowable string and append it to the password:
    $pass .= $allowable_characters[mt_rand(0, $len)];
  }

  return $pass;
}

/**
 * Determine the permissions for one or more roles.
 *
 * @param $roles
 *   An array whose keys are the role IDs of interest, such as $user->roles.
 * @param $reset
 *   Optional parameter - if TRUE data in the static variable is rebuilt.
 *
 * @return
 *   An array indexed by role ID. Each value is an array whose keys are the
 *   permission strings for the given role ID.
 */
function user_role_permissions($roles = array(), $reset = FALSE) {
  static $stored_permissions = array();

  if ($reset) {
    // Clear the data cached in the static variable.
    $stored_permissions = array();
  }

  $role_permissions = $fetch = array();

  if ($roles) {
    foreach ($roles as $rid => $name) {
      if (isset($stored_permissions[$rid])) {
        $role_permissions[$rid] = $stored_permissions[$rid];
      }
      else {
        // Add this rid to the list of those needing to be fetched.
        $fetch[] = $rid;
        // Prepare in case no permissions are returned.
        $stored_permissions[$rid] = array();
      }
    }

    if ($fetch) {
      // Get from the database permissions that were not in the static variable.
      // Only role IDs with at least one permission assigned will return rows.
      $result = db_query("SELECT r.rid, p.permission FROM {role} r INNER JOIN {role_permission} p ON p.rid = r.rid WHERE r.rid IN (" . db_placeholders($fetch) . ")", $fetch);

      while ($row = db_fetch_array($result)) {
        $stored_permissions[$row['rid']][$row['permission']] = TRUE;
      }
      foreach ($fetch as $rid) {
        // For every rid, we know we at least assigned an empty array.
        $role_permissions[$rid] = $stored_permissions[$rid];
      }
    }
  }

  return $role_permissions;
}

/**
 * Determine whether the user has a given privilege.
 *
 * @param $string
 *   The permission, such as "administer nodes", being checked for.
 * @param $account
 *   (optional) The account to check, if not given use currently logged in user.
 * @param $reset
 *   (optional) Resets the user's permissions cache, which will result in a
 *   recalculation of the user's permissions. This is necessary to support
 *   dynamically added user roles.
 *
 * @return
 *   Boolean TRUE if the current user has the requested permission.
 *
 * All permission checks in Drupal should go through this function. This
 * way, we guarantee consistent behavior, and ensure that the superuser
 * can perform all actions.
 */
function user_access($string, $account = NULL, $reset = FALSE) {
  global $user;
  static $perm = array();

  if ($reset) {
    unset($perm);
  }

  if (is_null($account)) {
    $account = $user;
  }

  // User #1 has all privileges:
  if ($account->uid == 1) {
    return TRUE;
  }

  // To reduce the number of SQL queries, we cache the user's permissions
  // in a static variable.
  if (!isset($perm[$account->uid])) {
    $role_permissions = user_role_permissions($account->roles, $reset);

    $perms = array();
    foreach ($role_permissions as $one_role) {
      $perms += $one_role;
    }
    $perm[$account->uid] = $perms;
  }

  return isset($perm[$account->uid][$string]);
}

/**
 * Checks for usernames blocked by user administration.
 *
 * @return boolean TRUE for blocked users, FALSE for active.
 */
function user_is_blocked($name) {
  $deny = db_fetch_object(db_query("SELECT name FROM {users} WHERE status = 0 AND name = LOWER('%s')", $name));

  return $deny;
}

/**
 * Implementation of hook_perm().
 */
function user_perm() {
   return array(
     'administer permissions' => t('Manage the permissions assigned to user roles. %warning', array('%warning' => t('Warning: Give to trusted roles only; this permission has security implications.'))),
     'administer users' => t('Manage or block users, and manage their role assignments.'),
     'access user profiles' => t('View profiles of users on the site, which may contain personal information.'),
     'change own username' => t('Select a different username.'),
   );
}

/**
 * Implementation of hook_file_download().
 *
 * Ensure that user pictures (avatars) are always downloadable.
 */
function user_file_download($file) {
  if (strpos($file, variable_get('user_picture_path', 'pictures') . '/picture-') === 0) {
    $info = image_get_info(file_create_path($file));
    return array('Content-type: ' . $info['mime_type']);
  }
}

/**
 * Implementation of hook_search().
 */
function user_search($op = 'search', $keys = NULL, $skip_access_check = FALSE) {
  switch ($op) {
    case 'name':
      if ($skip_access_check || user_access('access user profiles')) {
        return t('Users');
      }
    case 'search':
      if (user_access('access user profiles')) {
        $find = array();
        // Replace wildcards with MySQL/PostgreSQL wildcards.
        $keys = preg_replace('!\*+!', '%', $keys);
        if (user_access('administer users')) {
          // Administrators can also search in the otherwise private email field.
          $result = pager_query("SELECT name, uid, mail FROM {users} WHERE LOWER(name) LIKE LOWER('%%%s%%') OR LOWER(mail) LIKE LOWER('%%%s%%')", 15, 0, NULL, $keys, $keys);
          while ($account = db_fetch_object($result)) {
            $find[] = array('title' => $account->name . ' (' . $account->mail . ')', 'link' => url('user/' . $account->uid, array('absolute' => TRUE)));
          }
        }
        else {
          $result = pager_query("SELECT name, uid FROM {users} WHERE LOWER(name) LIKE LOWER('%%%s%%')", 15, 0, NULL, $keys);
          while ($account = db_fetch_object($result)) {
            $find[] = array('title' => $account->name, 'link' => url('user/' . $account->uid, array('absolute' => TRUE)));
          }
        }
        return $find;
      }
  }
}

/**
 * Implementation of hook_elements().
 */
function user_elements() {
  return array(
    'user_profile_category' => array(),
    'user_profile_item' => array(),
  );
}

/**
 * Implementation of hook_user().
 */
function user_user($type, &$edit, &$account, $category = NULL) {
  if ($type == 'view') {
    $account->content['user_picture'] = array(
      '#value' => theme('user_picture', $account),
      '#weight' => -10,
    );
    if (!isset($account->content['summary'])) {
      $account->content['summary'] = array();
    }
    $account->content['summary'] += array(
      '#type' => 'user_profile_category',
      '#attributes' => array('class' => 'user-member'),
      '#weight' => 5,
      '#title' => t('History'),
    );
    $account->content['summary']['member_for'] =  array(
      '#type' => 'user_profile_item',
      '#title' => t('Member for'),
      '#markup' => format_interval(REQUEST_TIME - $account->created),
    );
  }
  if ($type == 'form' && $category == 'account') {
    $form_state = array();
    return user_edit_form($form_state, arg(1), $edit);
  }

  if ($type == 'validate' && $category == 'account') {
    return _user_edit_validate(arg(1), $edit);
  }

  if ($type == 'submit' && $category == 'account') {
    return _user_edit_submit(arg(1), $edit);
  }

  if ($type == 'categories') {
    return array(array('name' => 'account', 'title' => t('Account settings'), 'weight' => 1));
  }
}

function user_login_block() {
  $form = array(
    '#action' => url($_GET['q'], array('query' => drupal_get_destination())),
    '#id' => 'user-login-form',
    '#validate' => user_login_default_validators(),
    '#submit' => array('user_login_submit'),
  );
  $form['name'] = array('#type' => 'textfield',
    '#title' => t('Username'),
    '#maxlength' => USERNAME_MAX_LENGTH,
    '#size' => 15,
    '#required' => TRUE,
  );
  $form['pass'] = array('#type' => 'password',
    '#title' => t('Password'),
    '#maxlength' => 60,
    '#size' => 15,
    '#required' => TRUE,
  );
  $form['submit'] = array('#type' => 'submit',
    '#value' => t('Log in'),
  );
  $items = array();
  if (variable_get('user_register', 1)) {
    $items[] = l(t('Create new account'), 'user/register', array('attributes' => array('title' => t('Create a new user account.'))));
  }
  $items[] = l(t('Request new password'), 'user/password', array('attributes' => array('title' => t('Request new password via e-mail.'))));
  $form['links'] = array('#markup' => theme('item_list', $items));
  return $form;
}

/**
 * Implementation of hook_block().
 */
function user_block($op = 'list', $delta = '', $edit = array()) {
  global $user;

  if ($op == 'list') {
    $blocks['login']['info'] = t('User login');
    // Not worth caching.
    $blocks['login']['cache'] = BLOCK_NO_CACHE;

    $blocks['navigation']['info'] = t('Navigation');
    // Menu blocks can't be cached because each menu item can have
    // a custom access callback. menu.inc manages its own caching.
    $blocks['navigation']['cache'] = BLOCK_NO_CACHE;

    $blocks['new']['info'] = t('Who\'s new');

    // Too dynamic to cache.
    $blocks['online']['info'] = t('Who\'s online');
    $blocks['online']['cache'] = BLOCK_NO_CACHE;
    return $blocks;
  }
  else if ($op == 'configure' && $delta == 'new') {
    $form['user_block_whois_new_count'] = array(
      '#type' => 'select',
      '#title' => t('Number of users to display'),
      '#default_value' => variable_get('user_block_whois_new_count', 5),
      '#options' => drupal_map_assoc(array(1, 2, 3, 4, 5, 6, 7, 8, 9, 10)),
    );
    return $form;
  }
  else if ($op == 'configure' && $delta == 'online') {
    $period = drupal_map_assoc(array(30, 60, 120, 180, 300, 600, 900, 1800, 2700, 3600, 5400, 7200, 10800, 21600, 43200, 86400), 'format_interval');
    $form['user_block_seconds_online'] = array('#type' => 'select', '#title' => t('User activity'), '#default_value' => variable_get('user_block_seconds_online', 900), '#options' => $period, '#description' => t('A user is considered online for this long after they have last viewed a page.'));
    $form['user_block_max_list_count'] = array('#type' => 'select', '#title' => t('User list length'), '#default_value' => variable_get('user_block_max_list_count', 10), '#options' => drupal_map_assoc(array(0, 5, 10, 15, 20, 25, 30, 40, 50, 75, 100)), '#description' => t('Maximum number of currently online users to display.'));

    return $form;
  }
  else if ($op == 'save' && $delta == 'new') {
    variable_set('user_block_whois_new_count', $edit['user_block_whois_new_count']);
  }
  else if ($op == 'save' && $delta == 'online') {
    variable_set('user_block_seconds_online', $edit['user_block_seconds_online']);
    variable_set('user_block_max_list_count', $edit['user_block_max_list_count']);
  }
  else if ($op == 'view') {
    $block = array();

    switch ($delta) {
      case 'login':
        // For usability's sake, avoid showing two login forms on one page.
        if (!$user->uid && !(arg(0) == 'user' && !is_numeric(arg(1)))) {

          $block['subject'] = t('User login');
          $block['content'] = drupal_get_form('user_login_block');
        }
        return $block;

      case 'navigation':
        if ($menu = menu_tree()) {
          $block['subject'] = $user->uid ? check_plain($user->name) : t('Navigation');
          $block['content'] = $menu;
        }
        return $block;

      case 'new':
        if (user_access('access content')) {
          // Retrieve a list of new users who have subsequently accessed the site successfully.
          $result = db_query_range('SELECT uid, name FROM {users} WHERE status != 0 AND access != 0 ORDER BY created DESC', 0, variable_get('user_block_whois_new_count', 5));
          while ($account = db_fetch_object($result)) {
            $items[] = $account;
          }
          $output = theme('user_list', $items);

          $block['subject'] = t('Who\'s new');
          $block['content'] = $output;
        }
        return $block;

      case 'online':
        if (user_access('access content')) {
          // Count users active within the defined period.
          $interval = REQUEST_TIME - variable_get('user_block_seconds_online', 900);

          // Perform database queries to gather online user lists.  We use s.timestamp
          // rather than u.access because it is much faster.
          $anonymous_count = drupal_session_count($interval);
          $authenticated_users = db_query('SELECT DISTINCT u.uid, u.name, s.timestamp FROM {users} u INNER JOIN {sessions} s ON u.uid = s.uid WHERE s.timestamp >= %d AND s.uid > 0 ORDER BY s.timestamp DESC', $interval);
          $authenticated_count = 0;
          $max_users = variable_get('user_block_max_list_count', 10);
          $items = array();
          while ($account = db_fetch_object($authenticated_users)) {
            if ($max_users > 0) {
              $items[] = $account;
              $max_users--;
            }
            $authenticated_count++;
          }

          // Format the output with proper grammar.
          if ($anonymous_count == 1 && $authenticated_count == 1) {
            $output = t('There is currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', '@count users'), '%visitors' => format_plural($anonymous_count, '1 guest', '@count guests')));
          }
          else {
            $output = t('There are currently %members and %visitors online.', array('%members' => format_plural($authenticated_count, '1 user', '@count users'), '%visitors' => format_plural($anonymous_count, '1 guest', '@count guests')));
          }

          // Display a list of currently online users.
          $max_users = variable_get('user_block_max_list_count', 10);
          if ($authenticated_count && $max_users) {
            $output .= theme('user_list', $items, t('Online users'));
          }

          $block['subject'] = t('Who\'s online');
          $block['content'] = $output;
        }
        return $block;
    }
  }
}

/**
 * Process variables for user-picture.tpl.php.
 *
 * The $variables array contains the following arguments:
 * - $account
 *
 * @see user-picture.tpl.php
 */
function template_preprocess_user_picture(&$variables) {
  $variables['picture'] = '';
  if (variable_get('user_pictures', 0)) {
    $account = $variables['account'];
    if (!empty($account->picture) && file_exists($account->picture)) {
      $picture = file_create_url($account->picture);
    }
    else if (variable_get('user_picture_default', '')) {
      $picture = variable_get('user_picture_default', '');
    }

    if (isset($picture)) {
      $alt = t("@user's picture", array('@user' => $account->name ? $account->name : variable_get('anonymous', t('Anonymous'))));
      $variables['picture'] = theme('image', $picture, $alt, $alt, '', FALSE);
      if (!empty($account->uid) && user_access('access user profiles')) {
        $attributes = array('attributes' => array('title' => t('View user profile.')), 'html' => TRUE);
        $variables['picture'] = l($variables['picture'], "user/$account->uid", $attributes);
      }
    }
  }
}

/**
 * Make a list of users.
 *
 * @param $users
 *   An array with user objects. Should contain at least the name and uid.
 * @param $title
 *  (optional) Title to pass on to theme_item_list().
 *
 * @ingroup themeable
 */
function theme_user_list($users, $title = NULL) {
  if (!empty($users)) {
    foreach ($users as $user) {
      $items[] = theme('username', $user);
    }
  }
  return theme('item_list', $items, $title);
}

function user_is_anonymous() {
  // Menu administrators can see items for anonymous when administering.
  return !$GLOBALS['user']->uid || !empty($GLOBALS['menu_admin']);
}

function user_is_logged_in() {
  return (bool)$GLOBALS['user']->uid;
}

function user_register_access() {
  return user_is_anonymous() && variable_get('user_register', 1);
}

function user_view_access($account) {
  return $account && $account->uid &&
    (
      // Always let users view their own profile.
      ($GLOBALS['user']->uid == $account->uid) ||
      // Administrators can view all accounts.
      user_access('administer users') ||
      // The user is not blocked and logged in at least once.
      ($account->