TYPO3 Dual-Version Development: v13 & v14

Strategy: Write code that works on both TYPO3 v13 and v14, with v14 as the preferred target. All patterns in this skill are designed for dual-version compatibility.

1. Version Strategy

Target: TYPO3 v13 and v14

Best Practice: Target both v13 and v14 for maximum compatibility. New projects should prefer v14.

Version Constraints

<?php
// ext_emconf.php - Dual version support
$EM_CONF[$_EXTKEY] = [
    'title' => 'My Extension',
    'version' => '2.0.0',
    'state' => 'stable',
    'constraints' => [
        'depends' => [
            'typo3' => '13.0.0-14.99.99',
            'php' => '8.2.0-8.4.99',
        ],
        'conflicts' => [],
        'suggests' => [],
    ],
];

// composer.json - Dual version support
{
    "name": "vendor/my-extension",
    "type": "typo3-cms-extension",
    "require": {
        "php": "^8.2",
        "typo3/cms-core": "^13.0 || ^14.0"
    },
    "extra": {
        "typo3/cms": {
            "extension-key": "my_extension"
        }
    }
}

2. PHP Requirements

Minimum PHP Version: 8.2

Both v13 and v14 require PHP 8.2+. Use modern PHP features:

<?php
declare(strict_types=1);

namespace Vendor\Extension\Service;

// ✅ Constructor property promotion (PHP 8.0+)
final class MyService
{
    public function __construct(
        private readonly SomeDependency $dependency,
        private readonly AnotherService $anotherService,
    ) {}
}

// ✅ Named arguments (PHP 8.0+)
$result = $this->doSomething(
    name: 'value',
    options: ['key' => 'value'],
);

// ✅ Match expressions (PHP 8.0+)
$type = match ($input) {
    'a' => 'Type A',
    'b' => 'Type B',
    default => 'Unknown',
};

// ✅ Enums (PHP 8.1+)
enum Status: string
{
    case Draft = 'draft';
    case Published = 'published';
}

3. Controller Patterns (v13/v14 Compatible)

Extbase Action Controller

<?php
declare(strict_types=1);

namespace Vendor\Extension\Controller;

use Psr\Http\Message\ResponseInterface;
use TYPO3\CMS\Extbase\Mvc\Controller\ActionController;
use Vendor\Extension\Domain\Repository\ItemRepository;

final class ItemController extends ActionController
{
    public function __construct(
        private readonly ItemRepository $itemRepository,
    ) {}

    // ✅ Must return ResponseInterface (required since v13)
    public function listAction(): ResponseInterface
    {
        $items = $this->itemRepository->findAll();
        $this->view->assign('items', $items);
        return $this->htmlResponse();
    }

    public function showAction(int $item): ResponseInterface
    {
        $item = $this->itemRepository->findByUid($item);
        $this->view->assign('item', $item);
        return $this->htmlResponse();
    }

    // ✅ JSON response
    public function apiAction(): ResponseInterface
    {
        $data = ['success' => true, 'items' => []];
        return $this->jsonResponse(json_encode($data));
    }

    // ✅ Redirect
    public function createAction(): ResponseInterface
    {
        // Process creation...
        $this->addFlashMessage('Item created');
        return $this->redirect('list');
    }
}

Backend Module Controller

<?php
declare(strict_types=1);

namespace Vendor\Extension\Controller;

use Psr\Http\Message\ResponseInterface;
use Psr\Http\Message\ServerRequestInterface;
use TYPO3\CMS\Backend\Attribute\AsController;
use TYPO3\CMS\Backend\Template\ModuleTemplateFactory;

#[AsController]
final class BackendModuleController
{
    public function __construct(
        private readonly ModuleTemplateFactory $moduleTemplateFactory,
    ) {}

    public function indexAction(ServerRequestInterface $request): ResponseInterface
    {
        $moduleTemplate = $this->moduleTemplateFactory->create($request);
        $moduleTemplate->assign('items', []);
        
        return $moduleTemplate->renderResponse('Backend/Index');
    }
}

4. View & Templating (v13/v14 Compatible)

ViewFactory (Preferred Pattern)

<?php
declare(strict_types=1);

namespace Vendor\Extension\Service;

use Psr\Http\Message\ServerRequestInterface;
use TYPO3\CMS\Core\View\ViewFactoryData;
use TYPO3\CMS\Core\View\ViewFactoryInterface;

final class RenderingService
{
    public function __construct(
        private readonly ViewFactoryInterface $viewFactory,
    ) {}

    public function renderEmail(ServerRequestInterface $request, array $data): string
    {
        $viewFactoryData = new ViewFactoryData(
            templateRootPaths: ['EXT:my_extension/Resources/Private/Templates/Email'],
            partialRootPaths: ['EXT:my_extension/Resources/Private/Partials'],
            layoutRootPaths: ['EXT:my_extension/Resources/Private/Layouts

...