Creating Custom Modules

<?php
namespace Opencart\Admin\Controller\Extension\Myvendor\Module;

class Featured extends \Opencart\System\Engine\Controller {
    public function index(): void {
        $this->load->language('extension/myvendor/module/featured');
        
        $this->document->setTitle($this->language->get('heading_title'));
        
        // Handle form submission
        if (($this->request->server['REQUEST_METHOD'] == 'POST')) {
            $this->load->model('setting/setting');
            $this->model_setting_setting->editSetting('module_featured', $this->request->post);
            
            $this->session->data['success'] = $this->language->get('text_success');
            $this->response->redirect($this->url->link('marketplace/extension'));
        }
        
        // Prepare view data
        $data['module_featured_status'] = $this->config->get('module_featured_status');
        $data['module_featured_limit'] = $this->config->get('module_featured_limit');
        
        $this->response->setOutput($this->load->view('extension/myvendor/module/featured', $data));
    }
    
    public function install(): void {
        // Create database tables if needed
        $this->db->query("
            CREATE TABLE IF NOT EXISTS `" . DB_PREFIX . "featured_products` (
                `featured_id` int(11) NOT NULL AUTO_INCREMENT,
                `product_id` int(11) NOT NULL,
                `sort_order` int(3) NOT NULL DEFAULT '0',
                PRIMARY KEY (`featured_id`)
            ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4
        ");
    }
    
    public function uninstall(): void {
        // Clean up
        $this->db->query("DROP TABLE IF EXISTS `" . DB_PREFIX . "featured_products`");
    }
}

<?php
namespace Opencart\Catalog\Controller\Extension\Myvendor\Module;

class Featured extends \Opencart\System\Engine\Controller {
    public function index(array $setting): string {
        $this->load->language('extension/myvendor/module/featured');
        $this->load->model('catalog/product');
        
        // Get featured products
        $limit = isset($setting['limit']) ? (int)$setting['limit'] : 4;
        
        $products = $this->model_catalog_product->getProducts([
            'filter_featured' => true,
            'limit' => $limit
        ]);
        
        $data['products'] = [];
        
        foreach ($products as $product) {
            $data['products'][] = [
                'product_id' => $product['product_id'],
                'name'       => $product['name'],
                'price'      => $this->currency->format(
                    $product['price'],
                    $this->session->data['currency']
                ),
                'image'      => $this->model_tool_image->resize($product['image'], 200, 200),
                'href'       => $this->url->link('product/product', 'product_id=' . $product['product_id'])
            ];
        }
        
        return $this->load->view('extension/myvendor/module/featured', $data);
    }
}

<div class="featured-products">
    <h3>{{ heading_title }}</h3>
    
    <div class="row">
        {% for product in products %}
            <div class="col-md-3">
                <div class="product-card">
                    <a href="{{ product.href }}">
                        <img src="{{ product.image }}" alt="{{ product.name }}" />
                    </a>
                    <h4><a href="{{ product.href }}">{{ product.name }}</a></h4>
                    <p class="price">{{ product.price }}</p>
                </div>
            </div>
        {% endfor %}
    </div>
</div>

<?php
$_['heading_title']    = 'Featured Products';
$_['text_extension']   = 'Extensions';
$_['text_success']     = 'Success: You have modified featured products module!';
$_['entry_status']     = 'Status';
$_['entry_limit']      = 'Limit';

$this->load->model('design/layout');

$this->model_design_layout->addModule([
    'layout_id' => 1,
    'position'  => 'content_top',
    'code'      => 'featured',
    'sort_order' => 1
]);

// Save settings
$this->load->model('setting/setting');
$this->model_setting_setting->editSetting('module_featured', [
    'module_featured_status' => 1,
    'module_featured_limit'  => 8
]);

// Read settings
$status = $this->config->get('module_featured_status');
$limit = $this->config->get('module_featured_limit');