Custom PrestaShop Module Development

PrestaShop Custom Module Development

A module is the primary unit of PrestaShop extension. Through modules, any custom logic is implemented: from custom order fields to external API integrations. A module can register hooks, add controllers, extend database schema, add widgets to back-office through Symfony DI.

Module Structure

modules/mymodule/
├── mymodule.php             # Main module class
├── config.xml               # Metadata (optional)
├── composer.json            # Dependencies (optional)
├── logo.png                 # Icon 32x32
├── controllers/
│   └── front/
│       └── callback.php     # FrontController: /module/mymodule/callback
├── src/                     # PSR-4 namespace classes
│   ├── Entity/
│   ├── Repository/
│   └── Service/
├── views/
│   └── templates/
│       ├── admin/
│       │   └── configure.html.twig
│       └── hook/
│           └── display_banner.tpl
├── translations/            # Module translations
└── upgrade/                 # SQL migrations on update
    └── upgrade-1.1.0.php

Main Class and Lifecycle

<?php
declare(strict_types=1);

use PrestaShop\PrestaShop\Adapter\SymfonyContainer;

if (!defined('_PS_VERSION_')) {
    exit;
}

class MyModule extends Module
{
    public function __construct()
    {
        $this->name    = 'mymodule';
        $this->tab     = 'other';
        $this->version = '1.2.0';
        $this->author  = 'Company Name';
        $this->need_instance     = 0;
        $this->bootstrap         = true;
        $this->ps_versions_compliancy = ['min' => '8.0.0', 'max' => _PS_VERSION_];

        parent::__construct();

        $this->displayName = $this->trans('My Module', [], 'Modules.Mymodule.Admin');
        $this->description = $this->trans('Module description', [], 'Modules.Mymodule.Admin');
    }

    public function install(): bool
    {
        return parent::install()
            && $this->installDb()
            && $this->registerHook('actionOrderStatusPostUpdate')
            && $this->registerHook('displayCustomerAccount')
            && $this->registerHook('displayHeader');
    }

    public function uninstall(): bool
    {
        return parent::uninstall() && $this->uninstallDb();
    }

    private function installDb(): bool
    {
        $sql = 'CREATE TABLE IF NOT EXISTS `' . _DB_PREFIX_ . 'mymodule_data` (
            `id_mymodule` INT UNSIGNED NOT NULL AUTO_INCREMENT,
            `id_order`    INT UNSIGNED NOT NULL,
            `payload`     TEXT,
            `status`      TINYINT(1) NOT NULL DEFAULT 0,
            `date_add`    DATETIME NOT NULL,
            PRIMARY KEY (`id_mymodule`),
            KEY `id_order` (`id_order`)
        ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;';

        return Db::getInstance()->execute($sql);
    }
}

Working with Hooks

Hooks come in two types: action (modify behavior, return data) and display (return HTML). Important to distinguish:

// Display hook — returns HTML string
public function hookDisplayCustomerAccount(array $params): string
{
    $customerId = (int) $this->context->customer->id;
    $data = $this->getCustomerData($customerId);

    if (empty($data)) {
        return '';
    }

    $this->smarty->assign([
        'mymodule_data' => $data,
        'moduleUrl'     => $this->context->link->getModuleLink('mymodule', 'account'),
    ]);

    return $this->display(__FILE__, 'views/templates/hook/customer_account.tpl');
}

// Action hook — modifies data or performs side-effect
public function hookActionOrderStatusPostUpdate(array $params): void
{
    /** @var Order $order */
    $order  = $params['order'];
    $newStatus = $params['newOrderStatus'];

    if ((int) $newStatus->id === (int) Configuration::get('PS_OS_PAYMENT')) {
        $this->notifyExternalSystem($order);
    }
}

Symfony DI and Modern Back-office

PrestaShop 8.x allows Symfony DI in modules via config/services.yml:

# modules/mymodule/config/services.yml
services:
  _defaults:
    autowire: true
    autoconfigure: true
    public: true

  MyModule\Repository\OrderDataRepository:
    arguments:
      $connection: '@doctrine.dbal.default_connection'

  MyModule\Service\ExternalApiService:
    arguments:
      $apiKey: '%env(MYMODULE_API_KEY)%'
      $logger: '@logger'

Usage in back-office controller (Symfony-style):

// src/Controller/Admin/OrderDataController.php
namespace MyModule\Controller\Admin;

use PrestaShopBundle\Controller\Admin\FrameworkBundleAdminController;
use Symfony\Component\HttpFoundation\JsonResponse;
use MyModule\Repository\OrderDataRepository;

class OrderDataController extends FrameworkBundleAdminController
{
    public function __construct(
        private readonly OrderDataRepository $repository
    ) {}

    public function indexAction(int $orderId): JsonResponse
    {
        $data = $this->repository->findByOrderId($orderId);

        return $this->json([
            'success' => true,
            'data'    => $data,
        ]);
    }
}

Database Schema Migrations

Use upgrade scripts on module update:

// modules/mymodule/upgrade/upgrade-1.2.0.php
function upgrade_module_1_2_0(Module $module): bool
{
    $result = Db::getInstance()->execute(
        'ALTER TABLE `' . _DB_PREFIX_ . 'mymodule_data`
         ADD COLUMN `external_id` VARCHAR(128) NULL AFTER `id_order`,
         ADD INDEX `external_id` (`external_id`)'
    );

    if ($result) {
        // Data migration
        Db::getInstance()->execute(
            'UPDATE `' . _DB_PREFIX_ . 'mymodule_data` SET `status` = 1 WHERE `status` = 0 AND `date_add` < NOW()'
        );
    }

    return (bool) $result;
}

Module Localization

PrestaShop uses Symfony Translation for back-office and native mechanism for front-office:

// Back-office (Symfony Translation)
$this->trans('Order processed', [], 'Modules.Mymodule.Admin');

// Front-office (Smarty)
// In .tpl file:
// {l s='Order processed' mod='mymodule'}

// Generate translation files
php bin/console prestashop:generate:translations --module=mymodule

Module Testing

// tests/Unit/Service/ExternalApiServiceTest.php
use PHPUnit\Framework\TestCase;
use MyModule\Service\ExternalApiService;

class ExternalApiServiceTest extends TestCase
{
    public function testNotifyOrder(): void
    {
        $httpClient = $this->createMock(HttpClientInterface::class);
        $httpClient->expects($this->once())
            ->method('request')
            ->with('POST', 'https://api.example.com/orders')
            ->willReturn(new MockResponse('{"status":"ok"}', ['http_code' => 200]));

        $service = new ExternalApiService($httpClient, 'test-api-key');
        $result  = $service->notifyOrderPaid(12345);

        $this->assertTrue($result);
    }
}

Development Timeline

• Simple module: hooks, configuration, data output: 2–4 days
• Integration with external API (payment system, CRM): 5–10 days
• Module with custom entities, CRUD in back-office, migrations: 7–14 days
• Complex module (custom checkout, loyalty program): 3–6 weeks