CodeIgniter4/libraries/sessions.html
2025-02-07 17:48:15 +00:00

1330 lines
90 KiB
HTML
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<!DOCTYPE html>
<html class="writer-html5" lang="en">
<head>
<meta charset="utf-8" /><meta name="generator" content="Docutils 0.19: https://docutils.sourceforge.io/" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<title>Session Library &mdash; CodeIgniter 4.6.0 documentation</title>
<link rel="stylesheet" type="text/css" href="../_static/pygments.css" />
<link rel="stylesheet" type="text/css" href="../_static/css/citheme.css" />
<link rel="stylesheet" type="text/css" href="../_static/css/citheme_dark.css" />
<link rel="shortcut icon" href="../_static/favicon.ico"/>
<!--[if lt IE 9]>
<script src="../_static/js/html5shiv.min.js"></script>
<![endif]-->
<script data-url_root="../" id="documentation_options" src="../_static/documentation_options.js"></script>
<script src="../_static/jquery.js"></script>
<script src="../_static/underscore.js"></script>
<script src="../_static/_sphinx_javascript_frameworks_compat.js"></script>
<script src="../_static/doctools.js"></script>
<script src="../_static/sphinx_highlight.js"></script>
<script src="../_static/js/citheme.js"></script>
<script src="../_static/js/carbon.js"></script>
<script src="../_static/js/theme.js"></script>
<link rel="index" title="Index" href="../genindex.html" />
<link rel="search" title="Search" href="../search.html" />
<link rel="next" title="Throttler" href="throttler.html" />
<link rel="prev" title="Security" href="security.html" />
</head>
<body class="wy-body-for-nav">
<div class="wy-grid-for-nav">
<nav data-toggle="wy-nav-shift" class="wy-nav-side">
<div class="wy-side-scroll">
<div class="wy-side-nav-search" >
<a href="../index.html">
<img src="../_static/ci-logo-text.svg" class="logo" alt="Logo"/>
</a>
<div role="search">
<form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
<input type="text" name="q" placeholder="Search docs" aria-label="Search docs" />
<input type="hidden" name="check_keywords" value="yes" />
<input type="hidden" name="area" value="default" />
</form>
</div>
</div><div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="Navigation menu">
<ul>
<li class="toctree-l1"><a class="reference internal" href="../intro/index.html">Welcome to CodeIgniter4</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../intro/index.html">Welcome to CodeIgniter4</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/requirements.html">Server Requirements</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/credits.html">Credits</a></li>
<li class="toctree-l2"><a class="reference internal" href="../intro/psr.html">PSR Compliance</a></li>
<li class="toctree-l2"><a class="reference internal" href="../license.html">License Agreement</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../installation/installing_composer.html">Composer Installation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/installing_manual.html">Manual Installation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/running.html">Running Your App</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/deployment.html">Deployment</a></li>
<li class="toctree-l2"><a class="reference internal" href="../changelogs/index.html">Change Logs</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
<li class="toctree-l2"><a class="reference internal" href="../installation/repositories.html">CodeIgniter Repositories</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Build Your First Application</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static Pages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News Section</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create News Items</a></li>
<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../concepts/index.html">CodeIgniter4 Overview</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../concepts/structure.html">Application Structure</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/mvc.html">Models, Views, and Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/autoloader.html">Autoloading Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/services.html">Services</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/factories.html">Factories</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/http.html">Working with HTTP Requests</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/security.html">Security Guidelines</a></li>
<li class="toctree-l2"><a class="reference internal" href="../concepts/goals.html">Design and Architectural Goals</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../general/index.html">General Topics</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../general/configuration.html">Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/urls.html">CodeIgniter URLs</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/helpers.html">Helper Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/common_functions.html">Global Functions and Constants</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/logging.html">Logging Information</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/errors.html">Error Handling</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/caching.html">Web Page Caching</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/ajax.html">AJAX Requests</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/modules.html">Code Modules</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/managing_apps.html">Managing your Applications</a></li>
<li class="toctree-l2"><a class="reference internal" href="../general/environments.html">Handling Multiple Environments</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../incoming/index.html">Controllers and Routing</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../incoming/routing.html">URI Routing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/controllers.html">Controllers</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/filters.html">Controller Filters</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/auto_routing_improved.html">Auto Routing (Improved)</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/message.html">HTTP Messages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/request.html">Request Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/incomingrequest.html">IncomingRequest Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/content_negotiation.html">Content Negotiation</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/methodspoofing.html">HTTP Method Spoofing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../incoming/restful.html">RESTful Resource Handling</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../outgoing/index.html">Building Responses</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/views.html">Views</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_renderer.html">View Renderer</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_layouts.html">View Layouts</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_cells.html">View Cells</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_parser.html">View Parser</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/view_decorators.html">View Decorators</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/table.html">HTML Table Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/response.html">HTTP Responses</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/api_responses.html">API Response Trait</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/csp.html">Content Security Policy</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/localization.html">Localization</a></li>
<li class="toctree-l2"><a class="reference internal" href="../outgoing/alternative_php.html">Alternate PHP Syntax for View Files</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Working with Databases</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Methods</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting Metadata</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/events.html">Database Events</a></li>
<li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../models/index.html">Modeling Data</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../models/model.html">Using CodeIgniter's Model</a></li>
<li class="toctree-l2"><a class="reference internal" href="../models/entities.html">Using Entity Classes</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../dbmgmt/index.html">Managing Databases</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/forge.html">Database Forge</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/migration.html">Database Migrations</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/seeds.html">Database Seeding</a></li>
<li class="toctree-l2"><a class="reference internal" href="../dbmgmt/db_commands.html">Database Commands</a></li>
</ul>
</li>
</ul>
<ul class="current">
<li class="toctree-l1 current"><a class="reference internal" href="index.html">Library Reference</a><ul class="current">
<li class="toctree-l2"><a class="reference internal" href="caching.html">Caching Driver</a></li>
<li class="toctree-l2"><a class="reference internal" href="cookies.html">Cookies</a></li>
<li class="toctree-l2"><a class="reference internal" href="cors.html">Cross-Origin Resource Sharing (CORS)</a></li>
<li class="toctree-l2"><a class="reference internal" href="curlrequest.html">CURLRequest Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="email.html">Email Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="encryption.html">Encryption Service</a></li>
<li class="toctree-l2"><a class="reference internal" href="files.html">Working with Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="file_collections.html">File Collections</a></li>
<li class="toctree-l2"><a class="reference internal" href="honeypot.html">Honeypot Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="images.html">Image Manipulation Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="pagination.html">Pagination</a></li>
<li class="toctree-l2"><a class="reference internal" href="publisher.html">Publisher</a></li>
<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
<li class="toctree-l2 current"><a class="current reference internal" href="#">Session Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="throttler.html">Throttler</a></li>
<li class="toctree-l2"><a class="reference internal" href="time.html">Times and Dates</a></li>
<li class="toctree-l2"><a class="reference internal" href="typography.html">Typography</a></li>
<li class="toctree-l2"><a class="reference internal" href="uploaded_files.html">Working with Uploaded Files</a></li>
<li class="toctree-l2"><a class="reference internal" href="uri.html">Working with URIs</a></li>
<li class="toctree-l2"><a class="reference internal" href="user_agent.html">User Agent Class</a></li>
<li class="toctree-l2"><a class="reference internal" href="validation.html">Validation</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/filesystem_helper.html">Filesystem Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/test_helper.html">Test Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../testing/index.html">Testing</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../testing/overview.html">Getting Started</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/database.html">Database</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/fabricator.html">Generating Data</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/controllers.html">Controller Testing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/feature.html">HTTP Testing</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/response.html">Testing Responses</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/cli.html">Testing CLI Commands</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/mocking.html">Mocking</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/benchmark.html">Benchmarking</a></li>
<li class="toctree-l2"><a class="reference internal" href="../testing/debugging.html">Debugging Your Application</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../cli/index.html">Command Line Usage</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_overview.html">CLI Overview</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_controllers.html">Running Controllers via CLI</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/spark_commands.html">Spark Commands</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_commands.html">Creating Spark Commands</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_generators.html">CLI Generators</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_library.html">CLI Library</a></li>
<li class="toctree-l2"><a class="reference internal" href="../cli/cli_request.html">CLIRequest Class</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="../extending/index.html">Extending CodeIgniter</a><ul>
<li class="toctree-l2"><a class="reference internal" href="../extending/core_classes.html">Creating Core System Classes</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/common.html">Replacing Common Functions</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/events.html">Events</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/basecontroller.html">Extending the Controller</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/authentication.html">Authentication</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/composer_packages.html">Creating Composer Packages</a></li>
<li class="toctree-l2"><a class="reference internal" href="../extending/contributing.html">Contributing to CodeIgniter</a></li>
</ul>
</li>
</ul>
<ul>
<li class="toctree-l1"><a class="reference internal" href="official_packages.html">Official Packages</a></li>
</ul>
</div>
</div>
</nav>
<section data-toggle="wy-nav-shift" class="wy-nav-content-wrap"><nav class="wy-nav-top" aria-label="Mobile navigation menu" >
<i data-toggle="wy-nav-top" class="fa fa-bars"></i>
<a href="../index.html">CodeIgniter</a>
</nav>
<div class="wy-nav-content">
<div class="rst-content">
<a class="btn btn-neutral float-right" href="https://github.com/codeigniter4/CodeIgniter4/edit/develop/user_guide_src/source/libraries/sessions.rst">Edit this page</a>
<div role="navigation" aria-label="Page navigation">
<ul class="wy-breadcrumbs">
<li><a href="../index.html" class="icon icon-home" aria-label="Home"></a></li>
<li class="breadcrumb-item"><a href="index.html">Library Reference</a></li>
<li class="breadcrumb-item active">Session Library</li>
<li class="wy-breadcrumbs-aside">
</li>
</ul>
<hr/>
</div>
<div role="main" class="document" itemscope="itemscope" itemtype="http://schema.org/Article">
<div itemprop="articleBody">
<section id="session-library">
<h1>Session Library<a class="headerlink" href="#session-library" title="Permalink to this heading"></a></h1>
<p>The Session class permits you to maintain a users “state” and track their
activity while they browse your site.</p>
<p>CodeIgniter comes with a few session storage drivers, that you can see
in the last section of the table of contents:</p>
<nav class="contents local" id="contents">
<ul class="simple">
<li><p><a class="reference internal" href="#using-the-session-class" id="id3">Using the Session Class</a></p>
<ul>
<li><p><a class="reference internal" href="#initializing-a-session" id="id4">Initializing a Session</a></p></li>
<li><p><a class="reference internal" href="#how-do-sessions-work" id="id5">How Do Sessions Work?</a></p></li>
<li><p><a class="reference internal" href="#what-is-session-data" id="id6">What is Session Data?</a></p></li>
<li><p><a class="reference internal" href="#retrieving-session-data" id="id7">Retrieving Session Data</a></p></li>
<li><p><a class="reference internal" href="#adding-session-data" id="id8">Adding Session Data</a></p></li>
<li><p><a class="reference internal" href="#pushing-new-value-to-session-data" id="id9">Pushing New Value to Session Data</a></p></li>
<li><p><a class="reference internal" href="#removing-session-data" id="id10">Removing Session Data</a></p></li>
<li><p><a class="reference internal" href="#flashdata" id="id11">Flashdata</a></p></li>
<li><p><a class="reference internal" href="#tempdata" id="id12">Tempdata</a></p></li>
<li><p><a class="reference internal" href="#closing-a-session" id="id13">Closing a Session</a></p></li>
<li><p><a class="reference internal" href="#destroying-a-session" id="id14">Destroying a Session</a></p></li>
<li><p><a class="reference internal" href="#accessing-session-metadata" id="id15">Accessing Session Metadata</a></p></li>
</ul>
</li>
<li><p><a class="reference internal" href="#session-preferences" id="id16">Session Preferences</a></p></li>
<li><p><a class="reference internal" href="#session-drivers" id="id17">Session Drivers</a></p>
<ul>
<li><p><a class="reference internal" href="#filehandler-driver-the-default" id="id18">FileHandler Driver (the default)</a></p></li>
<li><p><a class="reference internal" href="#databasehandler-driver" id="id19">DatabaseHandler Driver</a></p></li>
<li><p><a class="reference internal" href="#redishandler-driver" id="id20">RedisHandler Driver</a></p></li>
<li><p><a class="reference internal" href="#memcachedhandler-driver" id="id21">MemcachedHandler Driver</a></p></li>
</ul>
</li>
</ul>
</nav>
<section id="using-the-session-class">
<h2><a class="toc-backref" href="#id3" role="doc-backlink">Using the Session Class</a><a class="headerlink" href="#using-the-session-class" title="Permalink to this heading"></a></h2>
<section id="initializing-a-session">
<h3><a class="toc-backref" href="#id4" role="doc-backlink">Initializing a Session</a><a class="headerlink" href="#initializing-a-session" title="Permalink to this heading"></a></h3>
<p>Sessions will typically run globally with each page load, so the Session
class should be magically initialized.</p>
<p>To access and initialize the session:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span> <span class="o">=</span> <span class="nx">service</span><span class="p">(</span><span class="s1">&#39;session&#39;</span><span class="p">,</span> <span class="nv">$config</span><span class="p">);</span>
</pre></div>
</div>
<p>The <code class="docutils literal notranslate"><span class="pre">$config</span></code> parameter is optional - your application configuration.
If not provided, the services register will instantiate your default
one.</p>
<p>Once loaded, the Sessions library object will be available using:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nv">$session</span>
</pre></div>
</div>
<p>Alternatively, you can use the helper function that will use the default
configuration options. This version is a little friendlier to read,
but does not take any configuration options.</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span> <span class="o">=</span> <span class="nx">session</span><span class="p">();</span>
</pre></div>
</div>
</section>
<section id="how-do-sessions-work">
<h3><a class="toc-backref" href="#id5" role="doc-backlink">How Do Sessions Work?</a><a class="headerlink" href="#how-do-sessions-work" title="Permalink to this heading"></a></h3>
<p>When a page is loaded, the session class will check to see if a valid
session cookie is sent by the users browser. If a session cookie does
<strong>not</strong> exist (or if it doesnt match one stored on the server or has
expired) a new session will be created and saved.</p>
<p>If a valid session does exist, its information will be updated. With each
update, the session ID may be regenerated if configured to do so.</p>
<p>Its important for you to understand that once initialized, the Session
class runs automatically. There is nothing you need to do to cause the
above behavior to happen. You can, as youll see below, work with session
data, but the process of reading, writing, and updating a session is
automatic.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Under CLI, the Session library will automatically halt itself,
as this is a concept based entirely on the HTTP protocol.</p>
</div>
<section id="a-note-about-concurrency">
<h4>A Note about Concurrency<a class="headerlink" href="#a-note-about-concurrency" title="Permalink to this heading"></a></h4>
<p>Unless youre developing a website with heavy AJAX usage, you can skip this
section. If you are, however, and if youre experiencing performance
issues, then this note is exactly what youre looking for.</p>
<p>Sessions in CodeIgniter v2.x didnt implement locking,
which meant that two HTTP requests using the same session could run exactly
at the same time. To use a more appropriate technical term - requests were
non-blocking.</p>
<p>However, non-blocking requests in the context of sessions also means
unsafe, because, modifications to session data (or session ID regeneration)
in one request can interfere with the execution of a second, concurrent
request. This detail was at the root of many issues and the main reason why
CodeIgniter 3 has a completely re-written Session library.</p>
<p>Why are we telling you this? Because it is likely that after trying to
find the reason for your performance issues, you may conclude that locking
is the issue and therefore look into how to remove the locks …</p>
<p>DO NOT DO THAT! Removing locks would be <strong>wrong</strong> and it will cause you
more problems!</p>
<p>Locking is not the issue, it is a solution. Your issue is that you still
have the session open, while youve already processed it and therefore no
longer need it. So, what you need is to close the session for the
current request after you no longer need it.</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">close</span><span class="p">();</span>
</pre></div>
</div>
</section>
</section>
<section id="what-is-session-data">
<h3><a class="toc-backref" href="#id6" role="doc-backlink">What is Session Data?</a><a class="headerlink" href="#what-is-session-data" title="Permalink to this heading"></a></h3>
<p>Session data is simply an array associated with a particular session ID
(cookie).</p>
<p>If youve used sessions in PHP before, you should be familiar with PHPs
<a class="reference external" href="https://www.php.net/manual/en/reserved.variables.session.php">$_SESSION superglobal</a>
(if not, please read the content on that link).</p>
<p>CodeIgniter gives access to its session data through the same means, as it
uses the session handlers mechanism provided by PHP. Using session data is
as simple as manipulating (read, set and unset values) the <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code>
array.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>In general, it is bad practice to use global variables.
So using the superglobal <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> directly is not recommended.</p>
</div>
<p>In addition, CodeIgniter also provides 2 special types of session data
that are further explained below: <a class="reference internal" href="#flashdata">Flashdata</a> and <a class="reference internal" href="#tempdata">Tempdata</a>.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>For historical reasons, we refer to session data excluding Flashdata and Tempdata as “userdata”.</p>
</div>
</section>
<section id="retrieving-session-data">
<h3><a class="toc-backref" href="#id7" role="doc-backlink">Retrieving Session Data</a><a class="headerlink" href="#retrieving-session-data" title="Permalink to this heading"></a></h3>
<p>Any piece of information from the session array is available through the
<code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> superglobal:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">];</span>
</pre></div>
</div>
<p>Or through the conventional accessor method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nv">$session</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>Or through the magic getter:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nv">$session</span><span class="o">-&gt;</span><span class="na">item</span><span class="p">;</span>
</pre></div>
</div>
<p>Or even through the session helper method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nx">session</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>Where <code class="docutils literal notranslate"><span class="pre">item</span></code> is the array key corresponding to the item you wish to fetch.
For example, to assign a previously stored <code class="docutils literal notranslate"><span class="pre">name</span></code> item to the <code class="docutils literal notranslate"><span class="pre">$name</span></code>
variable, you will do this:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$name</span> <span class="o">=</span> <span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;name&#39;</span><span class="p">];</span>
<span class="c1">// or:</span>
<span class="nv">$name</span> <span class="o">=</span> <span class="nv">$session</span><span class="o">-&gt;</span><span class="na">name</span><span class="p">;</span>
<span class="c1">// or:</span>
<span class="nv">$name</span> <span class="o">=</span> <span class="nv">$session</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">(</span><span class="s1">&#39;name&#39;</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The <code class="docutils literal notranslate"><span class="pre">get()</span></code> method returns null if the item you are trying
to access does not exist.</p>
</div>
<p>If you want to retrieve all of the existing session data, you can simply
omit the item key (magic getter only works for single property values):</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$userData</span> <span class="o">=</span> <span class="nv">$_SESSION</span><span class="p">;</span>
<span class="c1">// or:</span>
<span class="nv">$userData</span> <span class="o">=</span> <span class="nv">$session</span><span class="o">-&gt;</span><span class="na">get</span><span class="p">();</span>
</pre></div>
</div>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>The <code class="docutils literal notranslate"><span class="pre">get()</span></code> method WILL return flashdata or tempdata items when
retrieving a single item by key. It will not return flashdata or tempdata when
grabbing all data from the session, however.</p>
</div>
</section>
<section id="adding-session-data">
<h3><a class="toc-backref" href="#id8" role="doc-backlink">Adding Session Data</a><a class="headerlink" href="#adding-session-data" title="Permalink to this heading"></a></h3>
<p>Lets say a particular user logs into your site. Once authenticated, you
could add their username and e-mail address to the session, making that
data globally available to you without having to run a database query when
you need it.</p>
<p>You can simply assign data to the <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> array, as with any other
variable. Or as a property of <code class="docutils literal notranslate"><span class="pre">$session</span></code>.</p>
<p>You can pass an array containing your new session data to the
<code class="docutils literal notranslate"><span class="pre">set()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">set</span><span class="p">(</span><span class="nv">$array</span><span class="p">);</span>
</pre></div>
</div>
<p>Where <code class="docutils literal notranslate"><span class="pre">$array</span></code> is an associative array containing your new data. Heres
an example:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$newdata</span> <span class="o">=</span> <span class="p">[</span>
<span class="s1">&#39;username&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;johndoe&#39;</span><span class="p">,</span>
<span class="s1">&#39;email&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;johndoe@some-site.com&#39;</span><span class="p">,</span>
<span class="s1">&#39;logged_in&#39;</span> <span class="o">=&gt;</span> <span class="k">true</span><span class="p">,</span>
<span class="p">];</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">set</span><span class="p">(</span><span class="nv">$newdata</span><span class="p">);</span>
</pre></div>
</div>
<p>If you want to add session data one value at a time, <code class="docutils literal notranslate"><span class="pre">set()</span></code> also
supports this syntax:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">set</span><span class="p">(</span><span class="s1">&#39;some_name&#39;</span><span class="p">,</span> <span class="s1">&#39;some_value&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>If you want to verify that a session value exists, simply check with
<code class="docutils literal notranslate"><span class="pre">isset()</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="c1">// returns false if the &#39;some_name&#39; item doesn&#39;t exist or is null,</span>
<span class="c1">// true otherwise:</span>
<span class="k">if</span> <span class="p">(</span><span class="nb">isset</span><span class="p">(</span><span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;some_name&#39;</span><span class="p">]))</span> <span class="p">{</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
<p>Or you can call <code class="docutils literal notranslate"><span class="pre">has()</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">has</span><span class="p">(</span><span class="s1">&#39;some_name&#39;</span><span class="p">);</span>
</pre></div>
</div>
</section>
<section id="pushing-new-value-to-session-data">
<h3><a class="toc-backref" href="#id9" role="doc-backlink">Pushing New Value to Session Data</a><a class="headerlink" href="#pushing-new-value-to-session-data" title="Permalink to this heading"></a></h3>
<p>The <code class="docutils literal notranslate"><span class="pre">push()</span></code> method is used to push a new value onto a session value that is an array.
For instance, if the <code class="docutils literal notranslate"><span class="pre">hobbies</span></code> key contains an array of hobbies, you can add a new value onto the array like so:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">push</span><span class="p">(</span><span class="s1">&#39;hobbies&#39;</span><span class="p">,</span> <span class="p">[</span><span class="s1">&#39;sport&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;tennis&#39;</span><span class="p">]);</span>
</pre></div>
</div>
</section>
<section id="removing-session-data">
<h3><a class="toc-backref" href="#id10" role="doc-backlink">Removing Session Data</a><a class="headerlink" href="#removing-session-data" title="Permalink to this heading"></a></h3>
<p>Just as with any other variable, unsetting a value in <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> can be
done through <code class="docutils literal notranslate"><span class="pre">unset()</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nb">unset</span><span class="p">(</span><span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;some_name&#39;</span><span class="p">]);</span>
<span class="c1">// or multiple values:</span>
<span class="nb">unset</span><span class="p">(</span>
<span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;some_name&#39;</span><span class="p">],</span>
<span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;another_name&#39;</span><span class="p">]</span>
<span class="p">);</span>
</pre></div>
</div>
<p>Also, just as <code class="docutils literal notranslate"><span class="pre">set()</span></code> can be used to add information to a
session, <code class="docutils literal notranslate"><span class="pre">remove()</span></code> can be used to remove it, by passing the
session key. For example, if you wanted to remove <code class="docutils literal notranslate"><span class="pre">some_name</span></code> from your
session data array:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">remove</span><span class="p">(</span><span class="s1">&#39;some_name&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>This method also accepts an array of item keys to unset:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$array_items</span> <span class="o">=</span> <span class="p">[</span><span class="s1">&#39;username&#39;</span><span class="p">,</span> <span class="s1">&#39;email&#39;</span><span class="p">];</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">remove</span><span class="p">(</span><span class="nv">$array_items</span><span class="p">);</span>
</pre></div>
</div>
</section>
<section id="flashdata">
<span id="sessions-flashdata"></span><h3><a class="toc-backref" href="#id11" role="doc-backlink">Flashdata</a><a class="headerlink" href="#flashdata" title="Permalink to this heading"></a></h3>
<p>CodeIgniter supports “flashdata”, or session data that will only be
available for the next request, and is then automatically cleared.</p>
<p>This can be very useful, especially for one-time informational, error or
status messages (for example: “Record 2 deleted”).</p>
<p>It should be noted that flashdata variables are regular session variables,
managed inside the CodeIgniter session handler.</p>
<p>To mark an existing item as “flashdata”:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsFlashdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>If you want to mark multiple items as flashdata, simply pass the keys as an
array:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsFlashdata</span><span class="p">([</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="s1">&#39;item2&#39;</span><span class="p">]);</span>
</pre></div>
</div>
<p>To add flashdata:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;value&#39;</span><span class="p">;</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsFlashdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>Or alternatively, using the <code class="docutils literal notranslate"><span class="pre">setFlashdata()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">setFlashdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="s1">&#39;value&#39;</span><span class="p">);</span>
</pre></div>
</div>
<p>You can also pass an array to <code class="docutils literal notranslate"><span class="pre">setFlashdata()</span></code>, in the same manner as
<code class="docutils literal notranslate"><span class="pre">set()</span></code>.</p>
<p>Reading flashdata variables is the same as reading regular session data
through <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">];</span>
</pre></div>
</div>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>The <code class="docutils literal notranslate"><span class="pre">get()</span></code> method WILL return flashdata items when
retrieving a single item by key. It will not return flashdata when
grabbing all data from the session, however.</p>
</div>
<p>However, if you want to be sure that youre reading “flashdata” (and not
any other kind), you can also use the <code class="docutils literal notranslate"><span class="pre">getFlashdata()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">getFlashdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The <code class="docutils literal notranslate"><span class="pre">getFlashdata()</span></code> method returns null if the item cannot be
found.</p>
</div>
<p>Or to get an array with all flashdata, simply omit the key parameter:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">getFlashdata</span><span class="p">();</span>
</pre></div>
</div>
<p>If you find that you need to preserve a flashdata variable through an
additional request, you can do so using the <code class="docutils literal notranslate"><span class="pre">keepFlashdata()</span></code> method.
You can either pass a single item or an array of flashdata items to keep.</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">keepFlashdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">keepFlashdata</span><span class="p">([</span><span class="s1">&#39;item1&#39;</span><span class="p">,</span> <span class="s1">&#39;item2&#39;</span><span class="p">,</span> <span class="s1">&#39;item3&#39;</span><span class="p">]);</span>
</pre></div>
</div>
</section>
<section id="tempdata">
<h3><a class="toc-backref" href="#id12" role="doc-backlink">Tempdata</a><a class="headerlink" href="#tempdata" title="Permalink to this heading"></a></h3>
<p>CodeIgniter also supports “tempdata”, or session data with a specific
expiration time. After the value expires, or the session expires or is
deleted, the value is automatically removed.</p>
<p>Similarly to flashdata, tempdata variables are managed internally by the
CodeIgniter session handler.</p>
<p>To mark an existing item as “tempdata”, simply pass its key and expiry time
(in seconds!) to the <code class="docutils literal notranslate"><span class="pre">markAsTempdata()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="c1">// &#39;item&#39; will be erased after 300 seconds</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsTempdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="mi">300</span><span class="p">);</span>
</pre></div>
</div>
<p>You can mark multiple items as tempdata in two ways, depending on whether
you want them all to have the same expiry time or not:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="c1">// Both &#39;item&#39; and &#39;item2&#39; will expire after 300 seconds</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsTempdata</span><span class="p">([</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="s1">&#39;item2&#39;</span><span class="p">],</span> <span class="mi">300</span><span class="p">);</span>
<span class="c1">// &#39;item&#39; will be erased after 300 seconds, while &#39;item2&#39;</span>
<span class="c1">// will do so after only 240 seconds</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsTempdata</span><span class="p">([</span>
<span class="s1">&#39;item&#39;</span> <span class="o">=&gt;</span> <span class="mi">300</span><span class="p">,</span>
<span class="s1">&#39;item2&#39;</span> <span class="o">=&gt;</span> <span class="mi">240</span><span class="p">,</span>
<span class="p">]);</span>
</pre></div>
</div>
<p>To add tempdata:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">]</span> <span class="o">=</span> <span class="s1">&#39;value&#39;</span><span class="p">;</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">markAsTempdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="mi">300</span><span class="p">);</span> <span class="c1">// Expire in 5 minutes</span>
</pre></div>
</div>
<p>Or alternatively, using the <code class="docutils literal notranslate"><span class="pre">setTempdata()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">setTempdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">,</span> <span class="s1">&#39;value&#39;</span><span class="p">,</span> <span class="mi">300</span><span class="p">);</span>
</pre></div>
</div>
<p>You can also pass an array to <code class="docutils literal notranslate"><span class="pre">setTempdata()</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$tempdata</span> <span class="o">=</span> <span class="p">[</span><span class="s1">&#39;newuser&#39;</span> <span class="o">=&gt;</span> <span class="k">true</span><span class="p">,</span> <span class="s1">&#39;message&#39;</span> <span class="o">=&gt;</span> <span class="s1">&#39;Thanks for joining!&#39;</span><span class="p">];</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">setTempdata</span><span class="p">(</span><span class="nv">$tempdata</span><span class="p">,</span> <span class="k">null</span><span class="p">,</span> <span class="nv">$expire</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If the expiration is omitted or set to 0, the default
time-to-live value of 300 seconds (or 5 minutes) will be used.</p>
</div>
<p>To read a tempdata variable, again you can just access it through the
<code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> superglobal array:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$item</span> <span class="o">=</span> <span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">];</span>
</pre></div>
</div>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>The <code class="docutils literal notranslate"><span class="pre">get()</span></code> method WILL return tempdata items when
retrieving a single item by key. It will not return tempdata when
grabbing all data from the session, however.</p>
</div>
<p>Or if you want to be sure that youre reading “tempdata” (and not any
other kind), you can also use the <code class="docutils literal notranslate"><span class="pre">getTempdata()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">getTempdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The <code class="docutils literal notranslate"><span class="pre">getTempdata()</span></code> method returns null if the item cannot be
found.</p>
</div>
<p>And of course, if you want to retrieve all existing tempdata:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">getTempdata</span><span class="p">();</span>
</pre></div>
</div>
<p>If you need to remove a tempdata value before it expires, you can directly
unset it from the <code class="docutils literal notranslate"><span class="pre">$_SESSION</span></code> array:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nb">unset</span><span class="p">(</span><span class="nv">$_SESSION</span><span class="p">[</span><span class="s1">&#39;item&#39;</span><span class="p">]);</span>
</pre></div>
</div>
<p>However, this wont remove the marker that makes this specific item to be
tempdata (it will be invalidated on the next HTTP request), so if you
intend to reuse that same key in the same request, youd want to use
<code class="docutils literal notranslate"><span class="pre">removeTempdata()</span></code>:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">removeTempdata</span><span class="p">(</span><span class="s1">&#39;item&#39;</span><span class="p">);</span>
</pre></div>
</div>
</section>
<section id="closing-a-session">
<h3><a class="toc-backref" href="#id13" role="doc-backlink">Closing a Session</a><a class="headerlink" href="#closing-a-session" title="Permalink to this heading"></a></h3>
<section id="close">
<span id="session-close"></span><h4>close()<a class="headerlink" href="#close" title="Permalink to this heading"></a></h4>
<div class="versionadded">
<p><span class="versionmodified added">New in version 4.4.0.</span></p>
</div>
<p>To close the current session manually after you no longer need it, use the
<code class="docutils literal notranslate"><span class="pre">close()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">close</span><span class="p">();</span>
</pre></div>
</div>
<p>You do not have to close the session manually, PHP will close it automatically
after your script terminated. But as session data is locked to prevent concurrent
writes only one request may operate on a session at any time. You may improve
your site performance by closing the session as soon as all changes to session
data are done.</p>
<p>This method will work in exactly the same way as PHPs
<a class="reference external" href="https://www.php.net/session_write_close">session_write_close()</a> function.</p>
</section>
</section>
<section id="destroying-a-session">
<h3><a class="toc-backref" href="#id14" role="doc-backlink">Destroying a Session</a><a class="headerlink" href="#destroying-a-session" title="Permalink to this heading"></a></h3>
<section id="destroy">
<span id="session-destroy"></span><h4>destroy()<a class="headerlink" href="#destroy" title="Permalink to this heading"></a></h4>
<p>To clear the current session (for example, during a logout), you may
simply use the librarys <code class="docutils literal notranslate"><span class="pre">destroy()</span></code> method:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="nv">$session</span><span class="o">-&gt;</span><span class="na">destroy</span><span class="p">();</span>
</pre></div>
</div>
<p>This method will work in exactly the same way as PHPs
<a class="reference external" href="https://www.php.net/session_destroy">session_destroy()</a> function.</p>
<p>This must be the last session-related operation that you do during the same request.
All session data (including flashdata and tempdata) will be destroyed permanently.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>You do not have to call this method from usual code. Cleanup session
data rather than destroying the session.</p>
</div>
</section>
<section id="stop">
<span id="session-stop"></span><h4>stop()<a class="headerlink" href="#stop" title="Permalink to this heading"></a></h4>
<div class="deprecated">
<p><span class="versionmodified deprecated">Deprecated since version 4.3.5.</span></p>
</div>
<p>The session class also has the <code class="docutils literal notranslate"><span class="pre">stop()</span></code> method.</p>
<div class="admonition warning">
<p class="admonition-title">Warning</p>
<p>Prior to v4.3.5, this method did not destroy the session due to a bug.</p>
</div>
<p>Starting with v4.3.5, this method has been modified to destroy the session.
However, it is deprecated because it is exactly the same as the <code class="docutils literal notranslate"><span class="pre">destroy()</span></code>
method. Use the <code class="docutils literal notranslate"><span class="pre">destroy()</span></code> method instead.</p>
</section>
</section>
<section id="accessing-session-metadata">
<h3><a class="toc-backref" href="#id15" role="doc-backlink">Accessing Session Metadata</a><a class="headerlink" href="#accessing-session-metadata" title="Permalink to this heading"></a></h3>
<p>In CodeIgniter 2, the session data array included 4 items
by default: session_id, ip_address, user_agent, last_activity.</p>
<p>This was due to the specifics of how sessions worked, but is now no longer
necessary with our new implementation. However, it may happen that your
application relied on these values, so here are alternative methods of
accessing them:</p>
<blockquote>
<div><ul class="simple">
<li><p>session_id: <code class="docutils literal notranslate"><span class="pre">$session-&gt;session_id</span></code> or <code class="docutils literal notranslate"><span class="pre">session_id()</span></code> (PHPs built-in function)</p></li>
<li><p>ip_address: <code class="docutils literal notranslate"><span class="pre">$_SERVER['REMOTE_ADDR']</span></code></p></li>
<li><p>user_agent: <code class="docutils literal notranslate"><span class="pre">$_SERVER['HTTP_USER_AGENT']</span></code> (unused by sessions)</p></li>
<li><p>last_activity: Depends on the storage, no straightforward way. Sorry!</p></li>
</ul>
</div></blockquote>
</section>
</section>
<section id="session-preferences">
<h2><a class="toc-backref" href="#id16" role="doc-backlink">Session Preferences</a><a class="headerlink" href="#session-preferences" title="Permalink to this heading"></a></h2>
<p>CodeIgniter will usually make everything work out of the box. However,
Sessions are a very sensitive component of any application, so some
careful configuration must be done. Please take your time to consider
all of the options and their effects.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Since v4.3.0, the new <strong>app/Config/Session.php</strong> has been added.
Previously, the Session Preferences were in your <strong>app/Config/App.php</strong> file.</p>
</div>
<p>Youll find the following Session related preferences in your
<strong>app/Config/Session.php</strong> file:</p>
<table class="docutils align-default">
<thead>
<tr class="row-odd"><th class="head"><p>Preference</p></th>
<th class="head"><p>Default</p></th>
<th class="head"><p>Options</p></th>
<th class="head"><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><strong>driver</strong></p></td>
<td><p>CodeIgniter\Session\Handlers\FileHandler</p></td>
<td><p>CodeIgniter\Session\Handlers\FileHandler
CodeIgniter\Session\Handlers\DatabaseHandler
CodeIgniter\Session\Handlers\MemcachedHandler
CodeIgniter\Session\Handlers\RedisHandler
CodeIgniter\Session\Handlers\ArrayHandler</p></td>
<td><p>The session storage driver to use.</p></td>
</tr>
<tr class="row-odd"><td><p><strong>cookieName</strong></p></td>
<td><p>ci_session</p></td>
<td><p>[A-Za-z_-] characters only</p></td>
<td><p>The name used for the session cookie.</p></td>
</tr>
<tr class="row-even"><td><p><strong>expiration</strong></p></td>
<td><p>7200 (2 hours)</p></td>
<td><p>Time in seconds (integer)</p></td>
<td><p>The number of seconds you would like the session to last.
If you would like a non-expiring session (until browser is closed) set the value to zero: 0</p></td>
</tr>
<tr class="row-odd"><td><p><strong>savePath</strong></p></td>
<td><p>null</p></td>
<td><p>None</p></td>
<td><p>Specifies the storage location, depends on the driver being used.</p></td>
</tr>
<tr class="row-even"><td><p><strong>matchIP</strong></p></td>
<td><p>false</p></td>
<td><p>true/false (boolean)</p></td>
<td><p>Whether to validate the users IP address when reading the session cookie.
Note that some ISPs dynamically changes the IP, so if you want a non-expiring session you
will likely set this to false.</p></td>
</tr>
<tr class="row-odd"><td><p><strong>timeToUpdate</strong></p></td>
<td><p>300</p></td>
<td><p>Time in seconds (integer)</p></td>
<td><p>This option controls how often the session class will regenerate itself and create a new
session ID. Setting it to 0 will disable session ID regeneration.</p></td>
</tr>
<tr class="row-even"><td><p><strong>regenerateDestroy</strong></p></td>
<td><p>false</p></td>
<td><p>true/false (boolean)</p></td>
<td><p>Whether to destroy session data associated with the old session ID when auto-regenerating
the session ID. When set to false, the data will be later deleted by the garbage collector.</p></td>
</tr>
</tbody>
</table>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>As a last resort, the Session library will try to fetch PHPs
session related INI settings, as well as CodeIgniter 3 settings such as
sess_expire_on_close when any of the above is not configured.
However, you should never rely on this behavior as it can cause
unexpected results or be changed in the future. Please configure
everything properly.</p>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>If <code class="docutils literal notranslate"><span class="pre">expiration</span></code> is set to <code class="docutils literal notranslate"><span class="pre">0</span></code>, the <code class="docutils literal notranslate"><span class="pre">session.gc_maxlifetime</span></code>
setting set by PHP in session management will be used as-is
(often the default value of <code class="docutils literal notranslate"><span class="pre">1440</span></code>). This needs to be changed in
<code class="docutils literal notranslate"><span class="pre">php.ini</span></code> or via <code class="docutils literal notranslate"><span class="pre">ini_set()</span></code> as needed.</p>
</div>
<p>In addition to the values above, the Session cookie uses the
following configuration values in your <strong>app/Config/Cookie.php</strong> file:</p>
<table class="docutils align-default">
<thead>
<tr class="row-odd"><th class="head"><p>Preference</p></th>
<th class="head"><p>Default</p></th>
<th class="head"><p>Description</p></th>
</tr>
</thead>
<tbody>
<tr class="row-even"><td><p><strong>domain</strong></p></td>
<td><p></p></td>
<td><p>The domain for which the session is applicable</p></td>
</tr>
<tr class="row-odd"><td><p><strong>path</strong></p></td>
<td><p>/</p></td>
<td><p>The path to which the session is applicable</p></td>
</tr>
<tr class="row-even"><td><p><strong>secure</strong></p></td>
<td><p>false</p></td>
<td><p>Whether to create the session cookie only on encrypted (HTTPS) connections</p></td>
</tr>
<tr class="row-odd"><td><p><strong>sameSite</strong></p></td>
<td><p>Lax</p></td>
<td><p>The SameSite setting for the session cookie</p></td>
</tr>
</tbody>
</table>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The <code class="docutils literal notranslate"><span class="pre">httponly</span></code> setting (in <strong>app/Config/Cookie.php</strong>) doesnt have an effect on sessions.
Instead the HttpOnly parameter is always enabled, for security
reasons. Additionally, the <code class="docutils literal notranslate"><span class="pre">Config\Cookie::$prefix</span></code> setting is completely
ignored.</p>
</div>
</section>
<section id="session-drivers">
<h2><a class="toc-backref" href="#id17" role="doc-backlink">Session Drivers</a><a class="headerlink" href="#session-drivers" title="Permalink to this heading"></a></h2>
<p>As already mentioned, the Session library comes with five handlers, or storage
engines, that you can use:</p>
<blockquote>
<div><ul class="simple">
<li><p>CodeIgniter\Session\Handlers\FileHandler</p></li>
<li><p>CodeIgniter\Session\Handlers\DatabaseHandler</p></li>
<li><p>CodeIgniter\Session\Handlers\MemcachedHandler</p></li>
<li><p>CodeIgniter\Session\Handlers\RedisHandler</p></li>
<li><p>CodeIgniter\Session\Handlers\ArrayHandler</p></li>
</ul>
</div></blockquote>
<p>By default, the <code class="docutils literal notranslate"><span class="pre">FileHandler</span></code> will be used when a session is initialized,
because it is the safest choice and is expected to work everywhere
(virtually every environment has a file system).</p>
<p>However, any other driver may be selected via the <code class="docutils literal notranslate"><span class="pre">$driver</span></code>
setting in your <strong>app/Config/Session.php</strong> file, if you chose to do so.
Have it in mind though, every driver has different caveats, so be sure to
get yourself familiar with them (below) before you make that choice.</p>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The ArrayHandler is used during testing and stores all data within
a PHP array, while preventing the data from being persisted.</p>
</div>
<section id="filehandler-driver-the-default">
<h3><a class="toc-backref" href="#id18" role="doc-backlink">FileHandler Driver (the default)</a><a class="headerlink" href="#filehandler-driver-the-default" title="Permalink to this heading"></a></h3>
<p>The FileHandler driver uses your file system for storing session data.</p>
<p>It can safely be said that it works exactly like PHPs own default session
implementation, but in case this is an important detail for you, in fact it is not the same code
and it has some limitations (and advantages).</p>
<p>To be more specific, it doesnt support PHPs <a class="reference external" href="https://www.php.net/manual/en/session.configuration.php#ini.session.save-path">directory level and mode
formats used in session.save_path</a>,
and it has most of the options hard-coded for safety. Instead, only
absolute paths are supported with <code class="docutils literal notranslate"><span class="pre">$savePath</span></code> setting.</p>
<p>Another important thing that you should know, is to make sure that you
dont use a publicly-readable or shared directory for storing your session
files. <em>Only you</em> should have access to the contents of your
chosen <em>savePath</em> directory. Otherwise, anybody can see and
steal session data (also known as “session fixation” attack).</p>
<p>On UNIX-like operating systems, this is usually achieved by setting the
0700 mode permissions on that directory via the <cite>chmod</cite> command, which
allows only the directorys owner to perform read and write operations on
it. But be careful because the system user <em>running</em> the script is usually
not your own, but something like www-data instead, so only setting those
permissions will probably break your application.</p>
<p>Instead, you should do something like this, depending on your environment:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="go">mkdir /&lt;path to your application directory&gt;/writable/sessions/</span>
<span class="go">chmod 0700 /&lt;path to your application directory&gt;/writable/sessions/</span>
<span class="go">chown www-data /&lt;path to your application directory&gt;/writable/sessions/</span>
</pre></div>
</div>
<section id="bonus-tip">
<h4>Bonus Tip<a class="headerlink" href="#bonus-tip" title="Permalink to this heading"></a></h4>
<p>Some of you will probably opt to choose another session driver because
file storage is usually slower. This is only half true.</p>
<p>A very basic test will probably trick you into believing that an SQL
database is faster, but in 99% of the cases, this is true only if you
have a few current sessions. As the sessions count and server loads
increase - which is the time when it matters - the file system will
consistently outperform almost all relational database setups.</p>
<p>In addition, if performance is your only concern, you may want to look
into using <a class="reference external" href="https://eddmann.com/posts/storing-php-sessions-file-caches-in-memory-using-tmpfs/">tmpfs</a>,
which can make your sessions blazing fast.</p>
</section>
</section>
<section id="databasehandler-driver">
<span id="sessions-databasehandler-driver"></span><h3><a class="toc-backref" href="#id19" role="doc-backlink">DatabaseHandler Driver</a><a class="headerlink" href="#databasehandler-driver" title="Permalink to this heading"></a></h3>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>Only MySQL and PostgreSQL databases are officially
supported, due to lack of advisory locking mechanisms on other
platforms. Using sessions without locks can cause all sorts of
problems, especially with heavy usage of AJAX. Use the <a class="reference internal" href="#session-close"><span class="std std-ref">close()</span></a> method
after youve done processing session data if youre having performance issues.</p>
</div>
<p>The DatabaseHandler driver uses a relational database such as MySQL or
PostgreSQL to store sessions. This is a popular choice among many users,
because it allows the developer easy access to the session data within
an application - it is just another table in your database.</p>
<p>However, there is a restriction: You can NOT use a persistent connection.</p>
<section id="configure-databasehandler">
<h4>Configure DatabaseHandler<a class="headerlink" href="#configure-databasehandler" title="Permalink to this heading"></a></h4>
<section id="setting-table-name">
<h5>Setting Table Name<a class="headerlink" href="#setting-table-name" title="Permalink to this heading"></a></h5>
<p>In order to use the DatabaseHandler session driver, you must also create this
table that we already mentioned and then set it as your
<code class="docutils literal notranslate"><span class="pre">$savePath</span></code> value.
For example, if you would like to use ci_sessions as your table name,
you would do this:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="k">namespace</span> <span class="nx">Config</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseConfig</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Session\Handlers\FileHandler</span><span class="p">;</span>
<span class="k">class</span> <span class="nc">Session</span> <span class="k">extends</span> <span class="nx">BaseConfig</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$driver</span> <span class="o">=</span> <span class="s1">&#39;CodeIgniter\Session\Handlers\DatabaseHandler&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$savePath</span> <span class="o">=</span> <span class="s1">&#39;ci_sessions&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
</section>
<section id="creating-database-table">
<h5>Creating Database Table<a class="headerlink" href="#creating-database-table" title="Permalink to this heading"></a></h5>
<p>And then of course, create the database table.</p>
<p>For MySQL:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nx">CREATE</span> <span class="nx">TABLE</span> <span class="k">IF</span> <span class="k">NOT</span> <span class="nx">EXISTS</span> <span class="sb">`ci_sessions`</span> <span class="p">(</span>
<span class="sb">`id`</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">128</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">null</span><span class="p">,</span>
<span class="sb">`ip_address`</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">45</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">null</span><span class="p">,</span>
<span class="sb">`timestamp`</span> <span class="nx">timestamp</span> <span class="k">DEFAULT</span> <span class="nx">CURRENT_TIMESTAMP</span> <span class="k">NOT</span> <span class="k">null</span><span class="p">,</span>
<span class="sb">`data`</span> <span class="nx">blob</span> <span class="k">NOT</span> <span class="k">null</span><span class="p">,</span>
<span class="nx">KEY</span> <span class="sb">`ci_sessions_timestamp`</span> <span class="p">(</span><span class="sb">`timestamp`</span><span class="p">)</span>
<span class="p">);</span>
</pre></div>
</div>
<p>For PostgreSQL:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nx">CREATE</span> <span class="nx">TABLE</span> <span class="s2">&quot;ci_sessions&quot;</span> <span class="p">(</span>
<span class="s2">&quot;id&quot;</span> <span class="nx">varchar</span><span class="p">(</span><span class="mi">128</span><span class="p">)</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="s2">&quot;ip_address&quot;</span> <span class="nx">inet</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="s2">&quot;timestamp&quot;</span> <span class="nx">timestamptz</span> <span class="k">DEFAULT</span> <span class="nx">CURRENT_TIMESTAMP</span> <span class="k">NOT</span> <span class="k">NULL</span><span class="p">,</span>
<span class="s2">&quot;data&quot;</span> <span class="nx">bytea</span> <span class="k">DEFAULT</span> <span class="s1">&#39;&#39;</span> <span class="k">NOT</span> <span class="k">NULL</span>
<span class="p">);</span>
<span class="nx">CREATE</span> <span class="nx">INDEX</span> <span class="s2">&quot;ci_sessions_timestamp&quot;</span> <span class="nx">ON</span> <span class="s2">&quot;ci_sessions&quot;</span> <span class="p">(</span><span class="s2">&quot;timestamp&quot;</span><span class="p">);</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>The <code class="docutils literal notranslate"><span class="pre">id</span></code> value contains the session cookie name (<code class="docutils literal notranslate"><span class="pre">Config\Session::$cookieName</span></code>)
and the session ID and a delimiter. It should be increased as needed, for example,
when using long session IDs.</p>
</div>
</section>
<section id="adding-primary-key">
<h5>Adding Primary Key<a class="headerlink" href="#adding-primary-key" title="Permalink to this heading"></a></h5>
<p>You will also need to add a PRIMARY KEY <strong>depending on your $matchIP
setting</strong>. The examples below work both on MySQL and PostgreSQL:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="c1">// When $matchIP = true</span>
<span class="nx">ALTER</span> <span class="nx">TABLE</span> <span class="nx">ci_sessions</span> <span class="nx">ADD</span> <span class="nx">PRIMARY</span> <span class="nx">KEY</span> <span class="p">(</span><span class="nx">id</span><span class="p">,</span> <span class="nx">ip_address</span><span class="p">);</span>
<span class="c1">// When $matchIP = false</span>
<span class="nx">ALTER</span> <span class="nx">TABLE</span> <span class="nx">ci_sessions</span> <span class="nx">ADD</span> <span class="nx">PRIMARY</span> <span class="nx">KEY</span> <span class="p">(</span><span class="nx">id</span><span class="p">);</span>
<span class="c1">// To drop a previously created primary key (use when changing the setting)</span>
<span class="nx">ALTER</span> <span class="nx">TABLE</span> <span class="nx">ci_sessions</span> <span class="nx">DROP</span> <span class="nx">PRIMARY</span> <span class="nx">KEY</span><span class="p">;</span>
</pre></div>
</div>
<div class="admonition important">
<p class="admonition-title">Important</p>
<p>If you dont add the correct primary key, the following error
may occur:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="nx">Uncaught</span> <span class="nx">mysqli_sql_exception</span><span class="o">:</span> <span class="nx">Duplicate</span> <span class="nx">entry</span> <span class="s1">&#39;ci_session:***&#39;</span> <span class="k">for</span> <span class="nb">key</span> <span class="s1">&#39;ci_sessions.PRIMARY&#39;</span>
</pre></div>
</div>
</div>
</section>
<section id="changing-database-group">
<h5>Changing Database Group<a class="headerlink" href="#changing-database-group" title="Permalink to this heading"></a></h5>
<p>The default database group is used by default.
You can change the database group to use by changing the <code class="docutils literal notranslate"><span class="pre">$DBGroup</span></code> property
in the <strong>app/Config/Session.php</strong> file to the name of the group to use:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="k">namespace</span> <span class="nx">Config</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseConfig</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Session\Handlers\FileHandler</span><span class="p">;</span>
<span class="k">class</span> <span class="nc">Session</span> <span class="k">extends</span> <span class="nx">BaseConfig</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="o">?</span><span class="nx">string</span> <span class="nv">$DBGroup</span> <span class="o">=</span> <span class="s1">&#39;groupName&#39;</span><span class="p">;</span>
<span class="p">}</span>
</pre></div>
</div>
</section>
<section id="setting-up-database-table-with-command">
<h5>Setting Up Database Table with Command<a class="headerlink" href="#setting-up-database-table-with-command" title="Permalink to this heading"></a></h5>
<p>If youd rather not do all of this by hand, you can use the <code class="docutils literal notranslate"><span class="pre">make:migration</span> <span class="pre">--session</span></code> command
from the cli to generate a migration file for you:</p>
<div class="highlight-console notranslate"><div class="highlight"><pre><span></span><span class="go">php spark make:migration --session</span>
<span class="go">php spark migrate</span>
</pre></div>
</div>
<p>This command will take the <code class="docutils literal notranslate"><span class="pre">$savePath</span></code> and <code class="docutils literal notranslate"><span class="pre">$matchIP</span></code> settings into account
when it generates the code.</p>
</section>
</section>
</section>
<section id="redishandler-driver">
<span id="sessions-redishandler-driver"></span><h3><a class="toc-backref" href="#id20" role="doc-backlink">RedisHandler Driver</a><a class="headerlink" href="#redishandler-driver" title="Permalink to this heading"></a></h3>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Since Redis doesnt have a locking mechanism exposed, locks for
this driver are emulated by a separate value that is kept for up
to 300 seconds.</p>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Starting with v4.3.2, you can connect Redis with <strong>TLS</strong> protocol.</p>
</div>
<p>Redis is a storage engine typically used for caching and popular because
of its high performance, which is also probably your reason to use the
RedisHandler session driver.</p>
<p>The downside is that it is not as ubiquitous as relational databases and
requires the <a class="reference external" href="https://github.com/phpredis/phpredis">phpredis</a> PHP
extension to be installed on your system, and that one doesnt come
bundled with PHP.
Chances are, youre using the RedisHandler driver only if youre already
both familiar with Redis and using it for other purposes.</p>
<section id="configure-redishandler">
<h4>Configure RedisHandler<a class="headerlink" href="#configure-redishandler" title="Permalink to this heading"></a></h4>
<p>Just as with the FileHandler and DatabaseHandler drivers, you must also configure
the storage location for your sessions via the
<code class="docutils literal notranslate"><span class="pre">$savePath</span></code> setting.
The format here is a bit different and complicated. It is
best explained by the <em>phpredis</em> extensions README file, so well simply
give a link to it:</p>
<blockquote>
<div><p><a class="reference external" href="https://github.com/phpredis/phpredis">https://github.com/phpredis/phpredis</a></p>
</div></blockquote>
<p>For the most common case however, a simple <code class="docutils literal notranslate"><span class="pre">host:port</span></code> pair should be
sufficient:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="k">namespace</span> <span class="nx">Config</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseConfig</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Session\Handlers\FileHandler</span><span class="p">;</span>
<span class="k">class</span> <span class="nc">Session</span> <span class="k">extends</span> <span class="nx">BaseConfig</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$driver</span> <span class="o">=</span> <span class="s1">&#39;CodeIgniter\Session\Handlers\RedisHandler&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$savePath</span> <span class="o">=</span> <span class="s1">&#39;tcp://localhost:6379&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
<p>Starting with v4.5.0, you can use Redis ACL (username and password):</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="k">public</span> <span class="nx">string</span> <span class="nv">$savePath</span> <span class="o">=</span> <span class="s1">&#39;tcp://localhost:6379?auth[user]=username&amp;auth[pass]=password&#39;</span><span class="p">;</span>
</pre></div>
</div>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Starting with v4.5.0, the interval time for acquiring locks
(<code class="docutils literal notranslate"><span class="pre">$lockRetryInterval</span></code>) and the number of retries (<code class="docutils literal notranslate"><span class="pre">$lockMaxRetries</span></code>) are
configurable.</p>
</div>
</section>
</section>
<section id="memcachedhandler-driver">
<span id="sessions-memcachedhandler-driver"></span><h3><a class="toc-backref" href="#id21" role="doc-backlink">MemcachedHandler Driver</a><a class="headerlink" href="#memcachedhandler-driver" title="Permalink to this heading"></a></h3>
<div class="admonition note">
<p class="admonition-title">Note</p>
<p>Since Memcached doesnt have a locking mechanism exposed, locks
for this driver are emulated by a separate value that is kept for
up to 300 seconds.</p>
</div>
<p>The MemcachedHandler driver is very similar to the RedisHandler one in all of its
properties, except perhaps for availability, because PHPs <a class="reference external" href="https://www.php.net/memcached">Memcached</a> extension is distributed via PECL and some
Linux distributions make it available as an easy to install package.</p>
<p>Other than that, and without any intentional bias towards Redis, theres
not much different to be said about Memcached - it is also a popular
product that is usually used for caching and famed for its speed.</p>
<p>However, it is worth noting that the only guarantee given by Memcached
is that setting value X to expire after Y seconds will result in it being
deleted after Y seconds have passed (but not necessarily that it wont
expire earlier than that time). This happens very rarely, but should be
considered as it may result in loss of sessions.</p>
<section id="configure-memcachedhandler">
<h4>Configure MemcachedHandler<a class="headerlink" href="#configure-memcachedhandler" title="Permalink to this heading"></a></h4>
<p>The <code class="docutils literal notranslate"><span class="pre">$savePath</span></code> format is fairly straightforward here,
being just a <code class="docutils literal notranslate"><span class="pre">host:port</span></code> pair:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="k">namespace</span> <span class="nx">Config</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseConfig</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Session\Handlers\FileHandler</span><span class="p">;</span>
<span class="k">class</span> <span class="nc">Session</span> <span class="k">extends</span> <span class="nx">BaseConfig</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$driver</span> <span class="o">=</span> <span class="s1">&#39;CodeIgniter\Session\Handlers\MemcachedHandler&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$savePath</span> <span class="o">=</span> <span class="s1">&#39;localhost:11211&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
</section>
<section id="id2">
<h4>Bonus Tip<a class="headerlink" href="#id2" title="Permalink to this heading"></a></h4>
<p>Multi-server configuration with an optional <em>weight</em> parameter as the
third colon-separated (<code class="docutils literal notranslate"><span class="pre">:weight</span></code>) value is also supported, but we have
to note that we havent tested if that is reliable.</p>
<p>If you want to experiment with this feature (on your own risk), simply
separate the multiple server paths with commas:</p>
<div class="highlight-html+php notranslate"><div class="highlight"><pre><span></span><span class="o">&lt;?</span><span class="nx">php</span>
<span class="k">namespace</span> <span class="nx">Config</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Config\BaseConfig</span><span class="p">;</span>
<span class="k">use</span> <span class="nx">CodeIgniter\Session\Handlers\FileHandler</span><span class="p">;</span>
<span class="k">class</span> <span class="nc">Session</span> <span class="k">extends</span> <span class="nx">BaseConfig</span>
<span class="p">{</span>
<span class="c1">// ...</span>
<span class="c1">// localhost will be given higher priority (5) here,</span>
<span class="c1">// compared to 192.0.2.1 with a weight of 1.</span>
<span class="k">public</span> <span class="nx">string</span> <span class="nv">$savePath</span> <span class="o">=</span> <span class="s1">&#39;localhost:11211:5,192.0.2.1:11211:1&#39;</span><span class="p">;</span>
<span class="c1">// ...</span>
<span class="p">}</span>
</pre></div>
</div>
</section>
</section>
</section>
</section>
</div>
</div>
<footer><div class="rst-footer-buttons" role="navigation" aria-label="Footer">
<a href="security.html" class="btn btn-neutral float-left" title="Security" accesskey="p" rel="prev"><span class="fa fa-arrow-circle-left" aria-hidden="true"></span> Previous</a>
<a href="throttler.html" class="btn btn-neutral float-right" title="Throttler" accesskey="n" rel="next">Next <span class="fa fa-arrow-circle-right" aria-hidden="true"></span></a>
</div>
<hr/>
<div role="contentinfo">
<p>&#169; Copyright 2019-2025 CodeIgniter Foundation.
<span class="lastupdated">Last updated on Feb 07, 2025.
</span></p>
</div>
Built with <a href="https://www.sphinx-doc.org/">Sphinx</a> using a
<a href="https://github.com/readthedocs/sphinx_rtd_theme">theme</a>
provided by <a href="https://readthedocs.org">Read the Docs</a>.
</footer>
</div>
</div>
</section>
</div>
<script>
jQuery(function () {
SphinxRtdTheme.Navigation.enable(false);
});
</script>
</body>
</html>