session_api.module in Session API 7

Session API provides an interface for storing information in the session.

File

session_api.module

<?php

/**
 * @file
 * Session API provides an interface for storing information in the session.
 */

/**
 * Determine if Session API is available by checking if cookies are enabled.
 */
function session_api_available() {
  return !empty($_COOKIE);
}

/**
 * Create an empty string cookie.
 *
 * This is useful for fooling the session_api_available() function when using
 * Pressflow, which does not set a cookie for anonymous users.
 */
function session_api_start_session() {
  $_SESSION[session_api_get_cookie_name()] = '';
  drupal_session_start();
}

/**
 * Returns the current session's Session ID.
 *
 * @param bool $create
 *   (optional) A boolean indicating whether the session needs to be created if
 *   it doesn't exist yet. Defaults to TRUE.
 *
 * @return
 *   Returns a positive integer with the Session ID when it exists. If not,
 *   there are 2 possible return values:
 *   - -1. This indicates that no session exists and none was created.
 *   - FALSE. This indicates that Session API is unavailable.
 *
 * @see drupal_session_initialize()
 */
function session_api_get_sid($create = TRUE) {
  $sid =& drupal_static(__FUNCTION__);
  if ($create) {

    // Must initialize sessions for anonymous users.
    session_api_start_session();
  }
  if (!session_api_available()) {
    return FALSE;
  }
  if (!isset($sid) || !$sid) {
    $sid = FALSE;

    // First, check if we already have an active session.
    if (isset($_COOKIE[session_api_get_cookie_name()]) && $_COOKIE[session_api_get_cookie_name()]) {
      $session_id = $_COOKIE[session_api_get_cookie_name()];
    }
    elseif (!$create) {

      // Return a negative value here, since it won't collide with any
      // session_api IDs.
      return -1;
    }
    else {
      $session_id = drupal_hash_base64(uniqid(mt_rand(), TRUE));
    }

    // Set expiration time. If 0, the cookie will expire when the session ends
    // (i.e, when the browser closes).
    $expire = variable_get('session_api_cookie_expire_time', 2592000);
    $expire_timestamp = $expire == 0 ? 0 : REQUEST_TIME + $expire;

    // Update the session timeout.
    db_merge('session_api')
      ->key(array(
      'session_id' => $session_id,
    ))
      ->fields(array(
      'timestamp' => REQUEST_TIME,
    ))
      ->execute();

    // Retrieve the sid.
    $query = db_select('session_api', 'sap');
    $query
      ->fields('sap', array(
      'sid',
    ));
    $query
      ->condition('session_id', $session_id);
    $sid = $query
      ->execute()
      ->fetchField();

    // Set cookie using the same domain that Drupal's own session cookie uses.
    $cookie_domain = ini_get('session.cookie_domain');
    setcookie(session_api_get_cookie_name(), $session_id, $expire_timestamp, '/', $cookie_domain);
  }
  return $sid;
}

/**
 * Implements hook_menu().
 */
function session_api_menu() {
  $items['admin/config/development/session-api'] = array(
    'title' => 'Session API Configuration',
    'description' => 'Configure Session API behavior.',
    'access arguments' => array(
      'administer site configuration',
    ),
    'page callback' => 'drupal_get_form',
    'page arguments' => array(
      'session_api_settings_form',
    ),
    'file' => 'session_api.admin.inc',
  );
  return $items;
}

/**
 * Implements hook_cron().
 */
function session_api_cron() {

  // Fetch list of outdated sids.
  $query = db_select('session_api', 'sap');
  $query
    ->fields('sap', array(
    'sid',
  ));
  $query
    ->condition('sap.timestamp', REQUEST_TIME - variable_get('session_api_cookie_purge_time', 2592000), '<');
  $outdated_sids = $query
    ->execute()
    ->fetchCol();
  if (!empty($outdated_sids)) {
    module_invoke_all('session_api_cleanup', $outdated_sids);
    db_delete('session_api')
      ->condition('sid', $outdated_sids)
      ->execute();
  }
}

/**
 * Get Cookie name to use for this module.
 */
function session_api_get_cookie_name() {
  return variable_get('session_api_cookie_name', 'session_api_session');
}

Functions

Name	Description
session_api_available	Determine if Session API is available by checking if cookies are enabled.
session_api_cron	Implements hook_cron().
session_api_get_cookie_name	Get Cookie name to use for this module.
session_api_get_sid	Returns the current session's Session ID.
session_api_menu	Implements hook_menu().
session_api_start_session	Create an empty string cookie.