WordPress Native PHP Sessions

Contributors: getpantheon, outlandish josh, mpvanwinkle77, danielbachhuber, andrew.taylor, jazzs3quence, stovak, jspellman
Tags: comments, sessions
Requires at least: 4.7
Tested up to: 6.2.2
Stable tag: 1.3.6
Requires PHP: 5.4
License: GPLv2 or later
License URI: http://www.gnu.org/licenses/gpl-2.0.html

Use native PHP sessions and stay horizontally scalable. Better living through superior technology.

Description

WordPress core does not use PHP sessions, but sometimes they are required by your use-case, a plugin or theme.

This plugin implements PHP's native session handlers, backed by the WordPress database. This allows plugins, themes, and custom code to safely use PHP $_SESSIONs in a distributed environment where PHP's default tempfile storage just won't work.

Note that primary development is on GitHub if you would like to contribute:

https://github.com/pantheon-systems/wp-native-php-sessions

Installation

1. Upload to the /wp-content/plugins/ directory
2. Activate the plugin through the 'Plugins' menu in WordPress

That's it!

Configuration

By default the session lifetime is set to 0, which is until the browser is closed.

To override this use the pantheon_session_expiration filter before the WordPress Native PHP Sessions plugin is loaded. For example a small Must-use plugin (a.k.a. mu-plugin) could contain:

<?php
function my_session_expiration_override() {
    return 60*60*4; // 4 hours
}
add_filter( 'pantheon_session_expiration', 'my_session_expiration_override' );

Contributing

See CONTRIBUTING.md for information on contributing.

Frequently Asked Questions

Why not use another session plugin?

This implements the built-in PHP session handling functions, rather than introducing anything custom. That way you can use built-in language functions like the $_SESSION superglobal and session_start() in your code. Everything else will "just work".

Why store them in the database?

PHP's fallback default functionality is to allow sessions to be stored in a temporary file. This is what most code that invokes sessions uses by default, and in simple use-cases it works, which is why so many plugins do it.

However, if you intend to scale your application, local tempfiles are a dangerous choice. They are not shared between different instances of the application, producing erratic behavior that can be impossible to debug. By storing them in the database the state of the sessions is shared across all application instances.

Troubleshooting

If you see an error like "Fatal error: session_start(): Failed to initialize storage module:" or "Warning: ini_set(): A session is active.", then you likely have a plugin that is starting a session before WP Native PHP Sessions is loading.

To fix, create a new file at wp-content/mu-plugins/000-loader.php and include the following:

<?php
require_once WP_PLUGIN_DIR . '/wp-native-php-sessions/pantheon-sessions.php';

This mu-plugin will load WP Native PHP Sessions before all other plugins, while letting you still use the WordPress plugin updater to keep the plugin up-to-date.

Changelog

1.3.6 (June 1, 2023)

• Fixes PHP 8.2 deprecated dynamic property error [#251] (props @miguelaxcar)
• Update CONTRIBUTING.md [#252].
• Update informational Error message for the case of headers already sent [#249].
• Add pantheon-wp-coding-standards [#247].

1.3.5 (April 7, 2023)

• Bump yoast/phpunit-polyfills from 1.0.4 to 1.0.5 [#245].
• Bump tested up to version

1.3.4 (February 7, 2023)

• Add fallback for $session->get_data() [[#237(#237)]] (reported on WordPress.org)
• Update CODEOWNERS file [#239]
• Fix GPL license in composer.json file [#236]
• Bump grunt from 1.5.3 to 1.6.1 [#235]

1.3.3 (January 25, 2023)

• Bump version in pantheon-sessions.php [#234].

1.3.2 (January 25, 2023)

• PHP 8.2 compatibility [#232].
• Bump dealerdirect/phpcodesniffer-composer-installer from 0.7.2 to 1.0.0 [#229].
• Update images for lint and test-behat jobs [#228].

1.3.1 (December 5, 2022)

• Document session lifetime handling [#224].
• Make dependabot target develop branch [#226].
• Ignore .wordpress-org directory [#223].

1.3.0 (November 28th, 2022)

• Added CONTRIBUTING.MD and GitHub action to automate deployments to wp.org. [#219]

1.2.5 (October 28th, 2022)

• Added #[ReturnTypeWillChange] where required to silence deprecation warnings in PHP 8.1. [#216]

1.2.4 (September 14th, 2021)

• Increases data blob size from 64k to 16M for new session tables; existing tables will need to manually modify the column if they want to apply this change [#193].

1.2.3 (April 9th, 2021)

• Assigns the table name to a variable before using in query [#188].

1.2.2 (March 29th, 2021)

• Includes an auto-incrementing id column for replication support [#187].

1.2.1 (September 17th, 2020)

• Plugin textdomain needs to be the same as the WordPress.org slug [#169].

1.2.0 (May 18th, 2020)

• Avoids using cookies for sessions when WP-CLI is executing [#154].

1.1.0 (April 23rd, 2020)

• Avoids initializing PHP sessions when doing cron [#149].

1.0.0 (March 2nd, 2020)

• Plugin is stable.

0.9.0 (October 14th, 2019)

• Refactors session callback logic into Session_Handler abstraction, fixing PHP notice in PHP 7.3 [#135].

0.8.1 (August 19th, 2019)

• Fixes handling of 'X-Forwarded-For' header in get_client_ip_server() [#126].

0.8.0 (August 13th, 2019)

• Respects various HTTP_* sources for client IP address [#122].

0.7.0 (April 3rd, 2019)

• Adds a safety check that restores $wpdb when it's missing.

0.6.9 (May 15th, 2018)

• Ensures _pantheon_session_destroy() uses a return value.

0.6.8 (May 4th, 2018)

• Switches to E_USER_WARNING instead of E_WARNING when triggering errors.

0.6.7 (April 26th, 2018)

• Disables plugin load when WP_INSTALLING, because session table creation breaks installation process.

0.6.6 (March 8th, 2018)

• Restores session instantiation when WP-CLI is executing, because not doing so causes other problems.

0.6.5 (February 6th, 2018)

• Disables session instantiation when defined( 'WP_CLI' ) && WP_CLI because sessions don't work on CLI.

0.6.4 (October 10th, 2017)

• Triggers PHP error when plugin fails to write session to database.

0.6.3 (September 29th, 2017)

• Returns false when we entirely fail to generate a session.

0.6.2 (June 6th, 2017)

• Syncs session user id when a user logs in and logs out.

0.6.1 (May 25th, 2017)

• Bug fix: Prevents warning session_write_close() expects exactly 0 parameters, 1 given.

0.6.0 (November 23rd, 2016)

• Bug fix: Prevents PHP fatal error in session_write_close() by running on WordPress' shutdown action, before $wpdb destructs itself.
• Bug fix: Stores the actual user id in the sessions table, instead of (bool) $user_id.

0.5

• Compatibility with PHP 7.
• Adds pantheon_session_expiration filter to modify session expiration value.

0.4

• Adjustment to session_id() behavior for wider compatibility
• Using superglobal for REQUEST_TIME as opposed to time()

0.3

• Fixes issue related to WordPress plugin load order

0.1

• Initial release