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Codeigniter Creating Controllers

Last modified on: September 7, 2025

<h1 data-start="475" data-end="517">📝 Creating Controllers in CodeIgniter</h1>
<h2 data-start="519" data-end="539">🔎 Introduction</h2>
<p data-start="540" data-end="621">In CodeIgniter, <strong data-start="556" data-end="571">Controllers</strong> act as the <strong data-start="583" data-end="618">bridge between Models and Views</strong>.</p>
<ul data-start="622" data-end="734">
<li data-start="622" data-end="657">
<p data-start="624" data-end="657">They <strong data-start="629" data-end="654">receive user requests</strong>,</p>
</li>
<li data-start="658" data-end="696">
<p data-start="660" data-end="696"><strong data-start="660" data-end="684">Interact with Models</strong> for data,</p>
</li>
<li data-start="697" data-end="734">
<p data-start="699" data-end="734"><strong data-start="699" data-end="713">Load Views</strong> to display output.</p>
</li>
</ul>
<p data-start="736" data-end="839">Creating a Controller is the first step to building any functional page in a CodeIgniter application.</p>
<hr data-start="841" data-end="844" />
<h2 data-start="846" data-end="880">📂 1. Location of Controllers</h2>
<ul data-start="882" data-end="973">
<li data-start="882" data-end="923">
<p data-start="884" data-end="923"><strong data-start="884" data-end="902">CodeIgniter 4:</strong> <code data-start="903" data-end="921">app/Controllers/</code></p>
</li>
<li data-start="924" data-end="973">
<p data-start="926" data-end="973"><strong data-start="926" data-end="944">CodeIgniter 3:</strong> <code data-start="945" data-end="971">application/controllers/</code></p>
</li>
</ul>
<p data-start="975" data-end="1064">All controller files should be named with <strong data-start="1017" data-end="1045">capitalized first letter</strong> for consistency.</p>
<hr data-start="1066" data-end="1069" />
<h2 data-start="1071" data-end="1109">⚙️ 2. Creating a Basic Controller</h2>
<h3 data-start="1111" data-end="1139">CodeIgniter 4 Example:</h3>
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<pre class="language-php"><code>&lt;?php
namespace App\Controllers;

class Home extends BaseController
{
    public function index()
    {
        return view('home_view');
    }
}
</code></pre>
</div>
</div>
</div>
</div>
<h3 data-start="1298" data-end="1326">CodeIgniter 3 Example:</h3>
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<pre class="language-php"><code>&lt;?php
defined('BASEPATH') OR exit('No direct script access allowed');

class Home extends CI_Controller {

public function index()
    {
        $this-&gt;load-&gt;view('home_view');
    }
}
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="1528" data-end="1546"><strong data-start="1528" data-end="1544">Explanation:</strong></p>
<ul data-start="1547" data-end="1700">
<li data-start="1547" data-end="1575">
<p data-start="1549" data-end="1575"><code data-start="1549" data-end="1555">Home</code> &rarr; Controller name</p>
</li>
<li data-start="1576" data-end="1654">
<p data-start="1578" data-end="1654"><code data-start="1578" data-end="1587">index()</code> &rarr; Default method executed when no method is specified in the URL</p>
</li>
<li data-start="1655" data-end="1700">
<p data-start="1657" data-end="1700"><code data-start="1657" data-end="1676">view('home_view')</code> &rarr; Loads the View file</p>
</li>
</ul>
<hr data-start="1702" data-end="1705" />
<h2 data-start="1707" data-end="1743">📂 3. Creating Multiple Methods</h2>
<p data-start="1745" data-end="1813">Controllers can have multiple methods to handle different actions:</p>
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<pre class="language-php"><code>&lt;?php
namespace App\Controllers;

class Products extends BaseController
{
    public function list()
    {
        return view('products_list');
    }

public function detail($id)
    {
        $data['id'] = $id;
        return view('product_detail', $data);
    }
}
</code></pre>
</div>
</div>
</div>
</div>
<p data-start="2098" data-end="2117"><strong data-start="2098" data-end="2115">URL Examples:</strong></p>
<ul data-start="2118" data-end="2214">
<li data-start="2118" data-end="2162">
<p data-start="2120" data-end="2162"><code data-start="2120" data-end="2136">/products/list</code> &rarr; Calls <code data-start="2145" data-end="2153">list()</code> method</p>
</li>
<li data-start="2163" data-end="2214">
<p data-start="2165" data-end="2214"><code data-start="2165" data-end="2185">/products/detail/5</code> &rarr; Calls <code data-start="2194" data-end="2205">detail(5)</code> method</p>
</li>
</ul>
<hr data-start="2216" data-end="2219" />
<h2 data-start="2221" data-end="2261">🔄 4. Loading Models in Controllers</h2>
<p data-start="2263" data-end="2330">Controllers often interact with <strong data-start="2295" data-end="2305">Models</strong> to fetch or save data.</p>
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<pre class="language-php"><code>&lt;?php
namespace App\Controllers;
use App\Models\ProductModel;

class Products extends BaseController
{
    public function detail($id)
    {
        $model = new ProductModel();
        $data['product'] = $model-&gt;find($id);

return view('product_detail', $data);
    }
}
</code></pre>
</div>
</div>
</div>
</div>
<ul data-start="2623" data-end="2716">
<li data-start="2623" data-end="2683">
<p data-start="2625" data-end="2683"><code data-start="2625" data-end="2644">$model-&gt;find($id)</code> &rarr; Fetches data from <code data-start="2665" data-end="2675">products</code> table</p>
</li>
<li data-start="2684" data-end="2716">
<p data-start="2686" data-end="2716"><code data-start="2686" data-end="2693">$data</code> &rarr; Passed to the View</p>
</li>
</ul>
<hr data-start="2718" data-end="2721" />
<h2 data-start="2723" data-end="2756">📄 5. Loading Multiple Views</h2>
<p data-start="2758" data-end="2807">You can combine multiple views in a controller:</p>
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<pre class="language-php"><code>public function index()
{
    echo view('header');
    echo view('home_view');
    echo view('footer');
}
</code></pre>
</div>
</div>
</div>
</div>
<ul data-start="2927" data-end="2983">
<li data-start="2927" data-end="2983">
<p data-start="2929" data-end="2983">Helps maintain a <strong data-start="2946" data-end="2967">consistent layout</strong> across pages.</p>
</li>
</ul>
<hr data-start="2985" data-end="2988" />
<h2 data-start="2990" data-end="3015">🔑 6. Best Practices</h2>
<ol data-start="3017" data-end="3322">
<li data-start="3017" data-end="3101">
<p data-start="3020" data-end="3101"><strong data-start="3020" data-end="3050">Name Controllers Properly:</strong> Capitalized, singular (e.g., <code data-start="3080" data-end="3089">Product</code>, <code data-start="3091" data-end="3097">User</code>).</p>
</li>
<li data-start="3102" data-end="3181">
<p data-start="3105" data-end="3181"><strong data-start="3105" data-end="3128">Keep Methods Small:</strong> Each method should handle a single responsibility.</p>
</li>
<li data-start="3182" data-end="3267">
<p data-start="3185" data-end="3267"><strong data-start="3185" data-end="3210">Avoid Business Logic:</strong> Models handle data and logic; controllers orchestrate.</p>
</li>
<li data-start="3268" data-end="3322">
<p data-start="3271" data-end="3322"><strong data-start="3271" data-end="3320">Use Constructor for Loading Models/Libraries:</strong></p>
</li>
</ol>
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<div class="sticky top-9">
<div class="absolute end-0 bottom-0 flex h-9 items-center pe-2">
<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>public function __construct()
{
    $this-&gt;productModel = new ProductModel();
}
</code></pre>
</div>
</div>
</div>
</div>
<ol start="5" data-start="3416" data-end="3500">
<li data-start="3416" data-end="3500">
<p data-start="3419" data-end="3500"><strong data-start="3419" data-end="3450">Use Routing for Clean URLs:</strong> Define custom routes in <code data-start="3475" data-end="3498">app/Config/Routes.php</code></p>
</li>
</ol>
<hr data-start="3502" data-end="3505" />
<h2 data-start="3507" data-end="3527">✅ 7. Conclusion</h2>
<ul data-start="3529" data-end="3725">
<li data-start="3529" data-end="3598">
<p data-start="3531" data-end="3598">Controllers are the <strong data-start="3551" data-end="3595">central point for handling user requests</strong>.</p>
</li>
<li data-start="3599" data-end="3636">
<p data-start="3601" data-end="3636">They <strong data-start="3606" data-end="3633">bridge models and views</strong>.</p>
</li>
<li data-start="3637" data-end="3725">
<p data-start="3639" data-end="3725">By following MVC, you can create <strong data-start="3672" data-end="3722">clean, maintainable, and scalable applications</strong>.</p>
</li>
</ul>
<p data-start="3727" data-end="3812"><strong data-start="3727" data-end="3744">Flow Summary:</strong><br data-start="3744" data-end="3747" />User Request &rarr; Controller &rarr; Model &rarr; Controller &rarr; View &rarr; Browser</p>

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