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Custom configuration files

Last modified on: September 9, 2025

<h1 data-start="452" data-end="500">⚙️ Custom Configuration Files in CodeIgniter</h1>
<h2 data-start="502" data-end="538">🔎 Why Use Custom Config Files?</h2>
<p data-start="539" data-end="695">By default, CodeIgniter comes with predefined config files (e.g., <code data-start="605" data-end="617">config.php</code>, <code data-start="619" data-end="633">database.php</code>).<br data-start="635" data-end="638" />But sometimes, your app needs <strong data-start="668" data-end="687">custom settings</strong> like:</p>
<ul data-start="696" data-end="806">
<li data-start="696" data-end="738">
<p data-start="698" data-end="738">API keys (Stripe, PayPal, Google Maps)</p>
</li>
<li data-start="739" data-end="769">
<p data-start="741" data-end="769">Application-wide constants</p>
</li>
<li data-start="770" data-end="789">
<p data-start="772" data-end="789">Feature toggles</p>
</li>
<li data-start="790" data-end="806">
<p data-start="792" data-end="806">Custom paths</p>
</li>
</ul>
<p data-start="808" data-end="890">👉 Instead of hardcoding values, you can manage them in <strong data-start="864" data-end="887">custom config files</strong>.</p>
<hr data-start="892" data-end="895" />
<h2 data-start="897" data-end="944">📂 1. Custom Config Files in CodeIgniter 3</h2>
<h3 data-start="946" data-end="978">Step 1: Create Config File</h3>
<p data-start="979" data-end="988">Inside:</p>
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<pre class="language-php"><code>application/config/
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1017" data-end="1058">Create a new file, e.g. <code data-start="1041" data-end="1055">myconfig.php</code>.</p>
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<pre class="language-php"><code>&lt;?php
defined('BASEPATH') OR exit('No direct script access allowed');

$config['site_name'] = 'My CodeIgniter App';
$config['items_per_page'] = 10;
$config['google_api_key'] = 'AIzaSyD-EXAMPLE-12345';
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="1273" data-end="1312">Step 2: Load Config in Controller</h3>
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<pre class="language-php"><code>$this-&gt;config-&gt;load('myconfig');
echo $this-&gt;config-&gt;item('site_name');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1398" data-end="1410">👉 Output:</p>
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<pre class="language-php"><code>My CodeIgniter App
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="1439" data-end="1480">Step 3: Auto-load Config (Optional)</h3>
<p data-start="1481" data-end="1515">If you want it always available:</p>
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<pre class="language-php"><code>application/config/autoload.php
</code></pre>
</div>
</div>
</div>
</div>
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<pre class="language-php"><code>$autoload['config'] = array('myconfig');
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1609" data-end="1639">Now you can use it anywhere:</p>
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<pre class="language-php"><code>echo $this-&gt;config-&gt;item('google_api_key');
</code></pre>
</div>
</div>
</div>
</div>
<hr data-start="1696" data-end="1699" />
<h2 data-start="1701" data-end="1748">📂 2. Custom Config Files in CodeIgniter 4</h2>
<p data-start="1750" data-end="1802">In CI4, configs are <strong data-start="1770" data-end="1781">classes</strong> instead of arrays.</p>
<h3 data-start="1804" data-end="1836">Step 1: Create Config File</h3>
<p data-start="1837" data-end="1846">Inside:</p>
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<div class="bg-token-bg-elevated-secondary text-token-text-secondary flex items-center gap-4 rounded-sm px-2 font-sans text-xs">
<pre class="language-php"><code>app/Config/
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1867" data-end="1891">Create <code data-start="1874" data-end="1888">MyConfig.php</code>.</p>
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<pre class="language-php"><code>&lt;?php namespace Config;

use CodeIgniter\Config\BaseConfig;

class MyConfig extends BaseConfig
{
    public $siteName = 'My CodeIgniter 4 App';
    public $itemsPerPage = 10;
    public $googleApiKey = 'AIzaSyD-EXAMPLE-12345';
}
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="2134" data-end="2173">Step 2: Load Config in Controller</h3>
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<pre class="language-php"><code>$config = new \Config\MyConfig();

echo $config-&gt;siteName;
echo $config-&gt;itemsPerPage;
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2274" data-end="2286">👉 Output:</p>
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<div class="bg-token-bg-elevated-secondary text-token-text-secondary flex items-center gap-4 rounded-sm px-2 font-sans text-xs">
<pre class="language-php"><code>My CodeIgniter 4 App
10
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="2320" data-end="2363">Step 3: Use <code data-start="2336" data-end="2342">.env</code> for Sensitive Data</h3>
<p data-start="2364" data-end="2419">Instead of hardcoding API keys, store them in <code data-start="2410" data-end="2416">.env</code>:</p>
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<pre class="language-php"><code>myconfig.siteName = "My Production App"
myconfig.googleApiKey = "AIzaSyD-PRODUCTION-KEY"
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2521" data-end="2540">Then access with:</p>
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<pre class="language-php"><code>$apiKey = env('myconfig.googleApiKey');
</code></pre>
</div>
</div>
</div>
</div>
<hr data-start="2593" data-end="2596" />
<h2 data-start="2598" data-end="2630">📊 CI3 vs CI4 Custom Config</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="2632" data-end="3476">
<thead data-start="2632" data-end="2751">
<tr data-start="2632" data-end="2751">
<th data-start="2632" data-end="2656" data-col-size="sm">Feature</th>
<th data-start="2656" data-end="2703" data-col-size="sm">CodeIgniter 3</th>
<th data-start="2703" data-end="2751" data-col-size="md">CodeIgniter 4</th>
</tr>
</thead>
<tbody data-start="2873" data-end="3476">
<tr data-start="2873" data-end="2992">
<td data-start="2873" data-end="2898" data-col-size="sm">Config Format</td>
<td data-start="2898" data-end="2944" data-col-size="sm">Array (<code data-start="2907" data-end="2932">$config['key'] = value;</code>)</td>
<td data-start="2944" data-end="2992" data-col-size="md">Class (<code data-start="2953" data-end="2975">public $key = value;</code>)</td>
</tr>
<tr data-start="2993" data-end="3112">
<td data-start="2993" data-end="3018" data-col-size="sm">File Location</td>
<td data-start="3018" data-end="3064" data-col-size="sm"><code data-start="3020" data-end="3041">application/config/</code></td>
<td data-start="3064" data-end="3112" data-col-size="md"><code data-start="3066" data-end="3079">app/Config/</code></td>
</tr>
<tr data-start="3113" data-end="3236">
<td data-start="3113" data-end="3138" data-col-size="sm">Access Method</td>
<td data-start="3138" data-end="3184" data-col-size="sm"><code data-start="3140" data-end="3168">$this-&gt;config-&gt;item('key')</code></td>
<td data-start="3184" data-end="3236" data-col-size="md"><code data-start="3186" data-end="3234">$config = new \Config\MyConfig(); $config-&gt;key</code></td>
</tr>
<tr data-start="3237" data-end="3356">
<td data-start="3237" data-end="3262" data-col-size="sm">Auto-loading</td>
<td data-start="3262" data-end="3308" data-col-size="sm"><code data-start="3264" data-end="3278">autoload.php</code></td>
<td data-start="3308" data-end="3356" data-col-size="md">Config class auto-loaded if instantiated</td>
</tr>
<tr data-start="3357" data-end="3476">
<td data-start="3357" data-end="3382" data-col-size="sm">Sensitive Data Storage</td>
<td data-start="3382" data-end="3428" data-col-size="sm">Hardcoded in PHP</td>
<td data-start="3428" data-end="3476" data-col-size="md">Recommended via <code data-start="3446" data-end="3452">.env</code> file</td>
</tr>
</tbody>
</table>
</div>
</div>
<hr data-start="3478" data-end="3481" />
<h2 data-start="3483" data-end="3504">✅ Best Practices</h2>
<ol data-start="3506" data-end="3836">
<li data-start="3506" data-end="3578">
<p data-start="3509" data-end="3578">Keep <strong data-start="3514" data-end="3532">sensitive data</strong> (API keys, DB credentials) in <code data-start="3563" data-end="3569">.env</code> (CI4).</p>
</li>
<li data-start="3579" data-end="3648">
<p data-start="3582" data-end="3648">Use <strong data-start="3586" data-end="3609">custom config files</strong> for reusable constants and settings.</p>
</li>
<li data-start="3649" data-end="3716">
<p data-start="3652" data-end="3716">Organize configs logically (e.g., <code data-start="3686" data-end="3697">email.php</code>, <code data-start="3699" data-end="3712">payment.php</code>).</p>
</li>
<li data-start="3717" data-end="3771">
<p data-start="3720" data-end="3771">Avoid hardcoding values in controllers or models.</p>
</li>
<li data-start="3772" data-end="3836">
<p data-start="3775" data-end="3836">Use <strong data-start="3779" data-end="3811">environment-specific configs</strong> (local vs production).</p>
</li>
</ol>
<hr data-start="3838" data-end="3841" />
<h2 data-start="3843" data-end="3867">🎯 Example Use Case</h2>
<h3 data-start="3869" data-end="3887">CI3 Example:</h3>
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<pre class="language-php"><code>// application/config/payment.php
$config['paypal_client_id'] = 'abc123';
$config['paypal_secret'] = 'xyz789';

// In controller
$this-&gt;config-&gt;load('payment');
echo $this-&gt;config-&gt;item('paypal_client_id');
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="4107" data-end="4125">CI4 Example:</h3>
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<pre class="language-php"><code>// app/Config/Payment.php
namespace Config;
class Payment extends \CodeIgniter\Config\BaseConfig {
    public $paypalClientId = 'abc123';
    public $paypalSecret   = 'xyz789';
}

// In controller
$paymentConfig = new \Config\Payment();
echo $paymentConfig-&gt;paypalClientId;
</code></pre>
</div>
</div>
</div>
</div>
<hr data-start="4412" data-end="4415" />
<p data-start="4417" data-end="4509">✅ With this setup, your CodeIgniter project stays <strong data-start="4467" data-end="4506">clean, secure, and easy to maintain</strong>.</p>

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