Services

This list is still incomplete.

ContaoFramework

This service manages and initializes Contao’s legacy framework. If you need any functionality from the legacy framework (e.g. Models) or you want to create adapters for Contao’s static classes, then you need to use this service.

use Contao\CoreBundle\Framework\ContaoFramework;

class Example
{
    private $framework;

    public function __construct(ContaoFramework $framework)
    {
        $this->framework = $framework;
    }

    public function execute()
    {
        $this->framework->initialize();

        $contentElement = \Contao\ContentModel::findByPk();

        $system = $this->framework->getAdapter(\Contao\System::class);
        $system->loadLanguageFile('default');
        
        // …
    }
}

CsrfTokenManager

This service allows you to generate and validate request tokens. You will need this service for custom forms for example that will allow the front end user to generate a POST request on a Contao route. Such requests need to have a valid request token present. Contao registers its own Symfony\Component\Security\Csrf\CsrfTokenManager under the service ID @contao.csrf.token_manager and configures its own token name under the parameter %contao.csrf_token_name%.

// src/Controller/ContentElement/ExampleFormElementController.php
namespace App\Controller\ContentElement;

use Contao\ContentModel;
use Contao\CoreBundle\Controller\ContentElement\AbstractContentElementController;
use Contao\CoreBundle\Csrf\ContaoCsrfTokenManager;
use Contao\CoreBundle\ServiceAnnotation\ContentElement;
use Contao\Template;
use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * @ContentElement(category="texts")
 */
class ExampleFormElementController extends AbstractContentElementController
{
    /**
     * @var ContaoCsrfTokenManager
     */
    private $csrfTokenManager;

    /**
     * @var string
     */
    private $csrfTokenName;

    public function __construct(ContaoCsrfTokenManager $csrfTokenManager, string $csrfTokenName)
    {
        $this->csrfTokenManager = $csrfTokenManager;
        $this->csrfTokenName = $csrfTokenName;
    }

    protected function getResponse(Template $template, ContentModel $model, Request $request): Response
    {
        $template->token = $this->csrfTokenManager->getToken($this->csrfTokenName)->getValue();

        return $template->getResponse();
    }
}
<!-- contao/templates/ce_example_form_element.html5 -->
<form>
  <input type="hidden" name="REQUEST_TOKEN" value="<?= $this->token ?>">
  <!-- … -->
</form>

Database Connection

Being able to operate on the database is of course a very common use case. Within Contao the database connection is provided via Symfony’s Doctrine Bundle. The bundle provides each configured database connection via its own service instance. The name of the service is doctrine.dbal.[name]_connection where [name] is the name of the database connection in your configuration. However, commonly you will only have one database in your Contao instance, the default connection. The default database connection will be available via the database_connection service (or doctrine.dbal.default_connection). All connection service instances will be of the type Doctrine\DBAL\Connection.

use Doctrine\DBAL\Connection;

class Example
{
    private $connection;

    public function __construct(Connection $connection)
    {
        $this->connection = $connection;
    }

    public function __invoke(): void
    {
        $records = $this->connection->fetchAllAssociative("SELECT * FROM tl_foobar");

        // …
    }
}

EntityCacheTags

This feature is available in Contao 4.13 and later.

The contao.cache.entity_tags service helps you tag responses and invalidate cache tags based on entity and model classes and instances. Contao uses a naming convention for database related tags: A tag contao.db.tl_content.5 targets the content element with the ID 5, while contao.db.tl_content would target all content elements.

Tagging

Instead of composing this tags yourself, let the service handle this for you by passing in class names or entity/model instances into one of its tagWith() methods:

// An instance of a blog post entity with relations to an author (1:1) and comment entity (1:n)
$blog = $blogRepository->find(42);

// Will add the following tags:
// 'contao.db.tl_blog.42', 'contao.db.tl_author.123', 'contao.db.tl_blog_comment.1', 'contao.db.tl_blog_comment.2'
$entityCacheTags->tagWith([$blog, $blog->getAuthor(), $blog->getComments()]);

// Will add the tag 'contao.db.tl_blog'
$entityCacheTags->tagWith(Blog::class);

Tagging works with entity/model class names, objects and collections. You can also safely pass in null.

Invalidating

Analogous to tagging, you can also use the service to invalidate certain cache tags. This, again, works with entity/model class names, objects and collections as well as null:

// Invalidates 'contao.db.tl_content', 'contao.db.tl_page.4', 'contao.db.tl_page.12'
$entityCacheTags->invalidateTagsFor([ContentModel::class, $pages]);

Contao’s AbstractController is also using this functionality in the tagResponse() method.

OptIn

This feature is available in Contao 4.7 and later.

Contao offers an opt-in service (contao.opt-in) so that any opt-in process can be tracked centrally. The opt-in references will be saved for the legally required duration and are then automatically discarded (if applicable).

namespace App;

use App\Model\ExampleModel;
use Contao\CoreBundle\OptIn\OptIn;

class Example
{
    private $optIn;

    public function __construct(OptIn $optIn)
    {
        $this->optIn = $optIn;
    }

    public function createOptIn(string $email, ExampleModel $model, string $optInUrl): void
    {
        $token = $this->optIn->create('example-', $email, ['tl_example' => [$model->id]]);
        $token->send('Opt-In', 'Click this link to opt-in: '.$optInUrl.'?token='.$token->getIdentifier());
    }

    public function confirmOptIn($tokenId): void
    {
        $token = $this->optIn->find($tokenId);

        if (null === $token) {
            throw new \RuntimeException('Invalid token identifier');
        }

        if ($token->isConfirmed()) {
            throw new \RuntimeException('Token already confirmed');
        }

        $related = $token->getRelatedRecords();

        if (1 !== count($related) || 'tl_example' !== key($related) || null === ExampleModel::findByPk(current($related))) {
            throw new \RuntimeException('Invalid token');
        }

        $token->confirm();
    }
}

Router

This service from symfony handles any routing task and can be ued to generate URLs to routes in your services.

use App\Controller\ExampleController;
use Symfony\Component\Routing\RouterInterface;

class Example
{
    private $router;

    public function __construct(RouterInterface $router)
    {
        $this->router = $router;
    }

    public function execute()
    {
        $url = $this->router->generate(ExampleController::class, ['id' => 1]);
    }
}

ScopeMatcher

The contao.routing.scope_matcher service provides the ability to identify the Contao scope of a request, if applicable. It should be used instead of checking the deprecated TL_MODE constant.

use Contao\CoreBundle\Routing\ScopeMatcher;
use Symfony\Component\HttpFoundation\RequestStack;

class Example
{
    private $requestStack;
    private $scopeMatcher;

    public function __construct(RequestStack $requestStack, ScopeMatcher $scopeMatcher)
    {
        $this->requestStack = $requestStack;
        $this->scopeMatcher = $scopeMatcher;
    }

    public function isBackend()
    {
        return $this->scopeMatcher->isBackendRequest($this->requestStack->getCurrentRequest());
    }

    public function isFrontend()
    {
        return $this->scopeMatcher->isFrontendRequest($this->requestStack->getCurrentRequest());
    }
}

Security Helper

Not directly related to Contao, but this helper service from Symfony lets you retrieve the current Contao front end or back end user from the firewall.

use Contao\BackendUser;
use Contao\FrontendUser;
use Symfony\Component\Security\Core\Security;

class Example
{
    private $security;

    public function __construct(Security $security)
    {
        $this->security = $security;
    }

    public function execute()
    {
        // Check for admin back end user role
        if ($this->security->isGranted('ROLE_ADMIN')) {
            // …
        }

        // Check for regular back end user role
        if ($this->security->isGranted('ROLE_USER')) {
            // …
        }

        // Check for front end user role
        if ($this->security->isGranted('ROLE_MEMBER')) {
            // …
        }

        // Get current back end user
        if (($user = $this->security->getUser()) instanceof BackendUser) {
            // …
        }

        // Get current front end user
        if (($user = $this->security->getUser()) instanceof FrontendUser) {
            // …
        }
    }
}

SimpleTokenParser

This feature is available in Contao 4.10 and later.

This service allows parsing simple tokens. See the usage examples from the tests for more details.

use Contao\CoreBundle\Util\SimpleTokenParser;

class Example
{
    private $parser;

    public function __construct(SimpleTokenParser $parser)
    {
        $this->parser = $parser;
    }

    public function execute()
    {
        // Token replacement
        $output = $this->parser->parse(
            'I like ##cms##.',
            ['cms' => 'Contao']
        );

        // Conditional expressions
        $output = $this->parser->parse(
            'This is {if value>=10}big{else}small{endif}',
            ['value' => 20]
        );
    }
}

Extending the parser

The simple token parser builds on top of the Symfony Expression Language. If you want to extend its functionality, you can register an expression provider that adds your own expression functions:

  1. Create a service that implements Symfony\Component\ExpressionLanguage\ExpressionFunctionProviderInterface
  2. Return an array of expression functions in the getFunctions() method
  3. Tag the service with contao.simple_token_extension

Slug

The contao.slug service can be used to generate a so called “slug”, i.e. a human-readable, unique identifier from non-standardized string. The service then in turn uses ausi/slug-generator and you can pass the same options as an associative array as the second parameter of the generate method:

namespace App;

use Contao\CoreBundle\Slug\Slug;

class Example
{
    private $slug;

    public function __construct(Slug $slug)
    {
        $this->slug = $slug;
    }

    public function getSlug(string $text, string $locale = 'en', string $validChars = '0-9a-z'): string
    {
        $options = [
            'locale' => $locale,
            'validChars' => $validChars,
        ];

        return $this->slug->generate($text, $options);
    }
}

When using the contao.slug service rather than the ausi/slug-generator directly additional Contao-specific processing of the passed string will take place, e.g. decoding HTML entities and stripping insert tags for example. The contao.slug service’s generate method also allows to pass a duplicate check as a callable for the third parameter. This check will be used to automatically append a number to the slug, if the slug already exists.

namespace App;

use Contao\CoreBundle\Slug\Slug;
use Doctrine\DBAL\Connection;

class Example
{
    private $slug;
    private $db;

    public function __construct(Slug $slug, Connection $db)
    {
        $this->slug = $slug;
        $this->db = $db;
    }

    public function getSlug(string $text, string $locale = 'en', string $validChars = '0-9a-zA-Z'): string
    {
        $options = [
            'locale' => $locale,
            'validChars' => $validChars,
        ];

        $duplicateCheck = function (string $slug): bool {
            return $this->slugExists($slug);
        };

        return $this->slug->generate($text, $options, $duplicateCheck);
    }

    private function slugExists(string $slug): bool
    {
        return !empty($this->db->fetchAllAssociative("SELECT * FROM tl_example WHERE slug = ?", [$slug]));
    }
}

TokenChecker

This service let’s you query information of the Contao related security tokens, if present. It allows you to check, whether a token for a front end user, back end user or the preview mode is present. It also allows you to retrieve the username of the token.

use Contao\CoreBundle\Security\Authentication\Token\TokenChecker;
use Contao\BackendUser;
use Contao\FrontendUser;

class Example
{
    private $tokenChecker;

    public function __construct(TokenChecker $tokenChecker)
    {
        $this->tokenChecker = $tokenChecker;
    }

    public function execute()
    {
        if ($this->tokenChecker->hasFrontendUser()) { /* … */ }
        if ($this->tokenChecker->hasBackendUser()) { /* … */ }
        if ($this->tokenChecker->isPreviewMode()) { /* … */ }
        if (null !== ($frontendUsername = $this->tokenChecker->getFrontendUsername())) { /* … */ }
        if (null !== ($backendUsername = $this->tokenChecker->getBackendUsername())) { /* … */ }
    }
}