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Auto-loading resources

Last modified on: September 9, 2025

<h1 data-start="478" data-end="522">📝 Auto-loading Resources in CodeIgniter</h1>
<h2 data-start="524" data-end="553">🔎 What is Auto-loading?</h2>
<p data-start="554" data-end="704">Auto-loading means <strong data-start="573" data-end="608">automatically loading resources</strong> (like libraries, helpers, models, configs) without manually loading them in every controller.</p>
<p data-start="706" data-end="746">👉 Instead of writing this everywhere:</p>
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<pre class="language-php"><code>$this-&gt;load-&gt;library('session');
$this-&gt;load-&gt;helper('url');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="819" data-end="909">You can <strong data-start="827" data-end="850">auto-load them once</strong>, and they will be available throughout your application.</p>
<hr data-start="911" data-end="914" />
<h2 data-start="916" data-end="956">📂 1. Auto-loading in CodeIgniter 3</h2>
<p data-start="958" data-end="1010">The <strong data-start="962" data-end="993">autoload configuration file</strong> is located at:</p>
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<pre class="language-php"><code>application/config/autoload.php
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="1052" data-end="1080">🔹 Auto-load Libraries</h3>
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<pre class="language-php"><code>$autoload['libraries'] = array('database', 'session', 'form_validation');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1166" data-end="1249">👉 Loads <code data-start="1175" data-end="1185">database</code>, <code data-start="1187" data-end="1196">session</code>, and <code data-start="1202" data-end="1219">form_validation</code> libraries for all requests.</p>
<h3 data-start="1251" data-end="1277">🔹 Auto-load Helpers</h3>
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<pre class="language-php"><code>$autoload['helper'] = array('url', 'form', 'html');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1341" data-end="1386">👉 Loads <code data-start="1350" data-end="1355">url</code>, <code data-start="1357" data-end="1363">form</code>, and <code data-start="1369" data-end="1375">html</code> helpers.</p>
<h3 data-start="1388" data-end="1413">🔹 Auto-load Models</h3>
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<pre class="language-php"><code>$autoload['model'] = array('User_model', 'Product_model');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1484" data-end="1528">👉 Loads <code data-start="1493" data-end="1505">User_model</code> and <code data-start="1510" data-end="1525">Product_model</code>.</p>
<h3 data-start="1530" data-end="1561">🔹 Auto-load Config Files</h3>
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<pre class="language-php"><code>$autoload['config'] = array('custom_config');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1619" data-end="1698">👉 Loads your custom config file from <code data-start="1657" data-end="1695">application/config/custom_config.php</code>.</p>
<hr data-start="1700" data-end="1703" />
<h2 data-start="1705" data-end="1745">📂 2. Auto-loading in CodeIgniter 4</h2>
<p data-start="1747" data-end="1837">In CodeIgniter 4, auto-loading is handled differently.<br data-start="1801" data-end="1804" />The main configuration file is:</p>
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<pre class="language-php"><code>app/Config/Autoload.php
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="1871" data-end="1900">🔹 Auto-load Namespaces</h3>
<p data-start="1901" data-end="1932">Add your custom namespace in:</p>
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<pre class="language-php"><code>public $psr4 = [
    'App'         =&gt; APPPATH, // Default
    'MyLibs'      =&gt; APPPATH . 'Libraries', // Custom namespace
];
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="2070" data-end="2096">🔹 Auto-load Helpers</h3>
<p data-start="2097" data-end="2128">In <code data-start="2100" data-end="2125">app/Config/Autoload.php</code>:</p>
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<pre class="language-php"><code>public $helpers = ['url', 'form', 'html'];
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2183" data-end="2216">👉 Loads helpers automatically.</p>
<h3 data-start="2218" data-end="2257">🔹 Auto-load Libraries (Services)</h3>
<p data-start="2258" data-end="2448">In CodeIgniter 4, libraries are usually loaded via <strong data-start="2309" data-end="2321">Services</strong>.<br data-start="2322" data-end="2325" />Example: Instead of autoloading in a config file, you can extend <code data-start="2390" data-end="2415">app/Config/Services.php</code> and preload services globally.</p>
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<pre class="language-php"><code>public static function customLib($getShared = true)
{
    if ($getShared) {
        return static::getSharedInstance('customLib');
    }
    return new \App\Libraries\CustomLib();
}
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2644" data-end="2655">Then use:</p>
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<pre class="language-php"><code>$custom = service('customLib');
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="2700" data-end="2725">🔹 Auto-load Models</h3>
<p data-start="2726" data-end="2839">Unlike CI3, CI4 does not have a direct <code data-start="2765" data-end="2785">$autoload['model']</code>.<br data-start="2786" data-end="2789" />Instead, you usually load models in controllers:</p>
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<pre class="language-php"><code>$this-&gt;userModel = new \App\Models\UserModel();
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2900" data-end="3008">👉 If you want models globally, you can load them in a <strong data-start="2955" data-end="2973">BaseController</strong> so they&rsquo;re available everywhere.</p>
<hr data-start="3010" data-end="3013" />
<h2 data-start="3015" data-end="3067">📊 3. Difference Between CI3 &amp; CI4 Auto-loading</h2>
<div class="_tableContainer_1rjym_1">
<div class="_tableWrapper_1rjym_13 group flex w-fit flex-col-reverse" tabindex="-1">
<table class="w-fit min-w-(--thread-content-width)" data-start="3069" data-end="3908">
<thead data-start="3069" data-end="3189">
<tr data-start="3069" data-end="3189">
<th data-start="3069" data-end="3093" data-col-size="sm">Feature</th>
<th data-start="3093" data-end="3138" data-col-size="sm">CodeIgniter 3</th>
<th data-start="3138" data-end="3189" data-col-size="md">CodeIgniter 4</th>
</tr>
</thead>
<tbody data-start="3310" data-end="3908">
<tr data-start="3310" data-end="3429">
<td data-start="3310" data-end="3334" data-col-size="sm">Config File</td>
<td data-start="3334" data-end="3379" data-col-size="sm"><code data-start="3336" data-end="3369">application/config/autoload.php</code></td>
<td data-start="3379" data-end="3429" data-col-size="md"><code data-start="3381" data-end="3406">app/Config/Autoload.php</code></td>
</tr>
<tr data-start="3430" data-end="3549">
<td data-start="3430" data-end="3454" data-col-size="sm">Auto-load Helpers</td>
<td data-start="3454" data-end="3499" data-col-size="sm"><code data-start="3456" data-end="3477">$autoload['helper']</code></td>
<td data-start="3499" data-end="3549" data-col-size="md"><code data-start="3501" data-end="3511">$helpers</code> array</td>
</tr>
<tr data-start="3550" data-end="3669">
<td data-start="3550" data-end="3574" data-col-size="sm">Auto-load Libraries</td>
<td data-start="3574" data-end="3619" data-col-size="sm"><code data-start="3576" data-end="3600">$autoload['libraries']</code></td>
<td data-start="3619" data-end="3669" data-col-size="md">Services (<code data-start="3631" data-end="3656">app/Config/Services.php</code>)</td>
</tr>
<tr data-start="3670" data-end="3789">
<td data-start="3670" data-end="3694" data-col-size="sm">Auto-load Models</td>
<td data-start="3694" data-end="3739" data-col-size="sm"><code data-start="3696" data-end="3716">$autoload['model']</code></td>
<td data-start="3739" data-end="3789" data-col-size="md">No direct autoload, load in <code data-start="3769" data-end="3785">BaseController</code></td>
</tr>
<tr data-start="3790" data-end="3908">
<td data-start="3790" data-end="3814" data-col-size="sm">Custom Namespaces</td>
<td data-start="3814" data-end="3859" data-col-size="sm">❌ Not available</td>
<td data-start="3859" data-end="3908" data-col-size="md">✅ Supported via <code data-start="3877" data-end="3884">$psr4</code> in <code data-start="3888" data-end="3902">Autoload.php</code></td>
</tr>
</tbody>
</table>
</div>
</div>
<hr data-start="3910" data-end="3913" />
<h2 data-start="3915" data-end="3937">🎯 Best Practices</h2>
<ol data-start="3939" data-end="4271">
<li data-start="3939" data-end="4028">
<p data-start="3942" data-end="4028"><strong data-start="3942" data-end="3969">Load only what you need</strong> &ndash; Don&rsquo;t auto-load everything, it slows down performance.</p>
</li>
<li data-start="4029" data-end="4105">
<p data-start="4032" data-end="4105"><strong data-start="4032" data-end="4069">Use autoload for common resources</strong> &ndash; e.g., <code data-start="4078" data-end="4083">url</code>, <code data-start="4085" data-end="4091">form</code>, <code data-start="4093" data-end="4102">session</code>.</p>
</li>
<li data-start="4106" data-end="4186">
<p data-start="4109" data-end="4186"><strong data-start="4109" data-end="4150">In CI4, keep models in BaseController</strong> &ndash; Helps avoid repetitive loading.</p>
</li>
<li data-start="4187" data-end="4271">
<p data-start="4190" data-end="4271"><strong data-start="4190" data-end="4213">Use Services in CI4</strong> &ndash; Best way to handle libraries and reusable components.</p>
</li>
</ol>
<hr data-start="4273" data-end="4276" />
<h2 data-start="4278" data-end="4295">✅ Conclusion</h2>
<ul data-start="4297" data-end="4643">
<li data-start="4297" data-end="4381">
<p data-start="4299" data-end="4381">Auto-loading makes resources available everywhere without manually loading them.</p>
</li>
<li data-start="4382" data-end="4459">
<p data-start="4384" data-end="4459"><strong data-start="4384" data-end="4391">CI3</strong> uses <code data-start="4397" data-end="4408">$autoload</code> arrays (<code data-start="4417" data-end="4428">libraries</code>, <code data-start="4430" data-end="4439">helpers</code>, <code data-start="4441" data-end="4449">models</code>, etc.).</p>
</li>
<li data-start="4460" data-end="4573">
<p data-start="4462" data-end="4573"><strong data-start="4462" data-end="4469">CI4</strong> uses <code data-start="4475" data-end="4489">Autoload.php</code> for helpers and namespaces, but models should be initialized in <code data-start="4554" data-end="4570">BaseController</code>.</p>
</li>
<li data-start="4574" data-end="4643">
<p data-start="4576" data-end="4643">Use auto-loading smartly for better performance and cleaner code.</p>
</li>
</ul>

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