.. index:: single: Routing; Custom route loader How to Create a custom Route Loader =================================== Simple applications can define all their routes in a single configuration file - usually ``config/routes.yaml`` (see :ref:`routing-creating-routes`). However, in most applications it's common to import routes definitions from different resources: PHP annotations in controller files, YAML, XML or PHP files stored in some directory, etc. Built-in Route Loaders ---------------------- Symfony provides several route loaders for the most common needs: .. configuration-block:: .. code-block:: yaml # config/routes.yaml app_file: # loads routes from the given routing file stored in some bundle resource: '@AcmeBundle/Resources/config/routing.yaml' app_annotations: # loads routes from the PHP annotations of the controllers found in that directory resource: '../src/Controller/' type: annotation app_directory: # loads routes from the YAML, XML or PHP files found in that directory resource: '../legacy/routing/' type: directory app_bundle: # loads routes from the YAML, XML or PHP files found in some bundle directory resource: '@AcmeOtherBundle/Resources/config/routing/' type: directory .. code-block:: xml .. code-block:: php // config/routes.php use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator; return function (RoutingConfigurator $routes) { // loads routes from the given routing file stored in some bundle $routes->import('@AcmeBundle/Resources/config/routing.yaml'); // loads routes from the PHP annotations of the controllers found in that directory $routes->import('../src/Controller/', 'annotation'); // loads routes from the YAML or XML files found in that directory $routes->import('../legacy/routing/', 'directory'); // loads routes from the YAML or XML files found in some bundle directory $routes->import('@AcmeOtherBundle/Resources/config/routing/', 'directory'); }; .. note:: When importing resources, the key (e.g. ``app_file``) is the name of collection. Just be sure that it's unique per file so no other lines override it. If your application needs are different, you can create your own custom route loader as explained in the next section. What is a Custom Route Loader ----------------------------- A custom route loader enables you to generate routes based on some conventions or patterns. A great example for this use-case is the `FOSRestBundle`_ where routes are generated based on the names of the action methods in a controller. You still need to modify your routing configuration (e.g. ``config/routes.yaml``) manually, even when using a custom route loader. .. note:: There are many bundles out there that use their own route loaders to accomplish cases like those described above, for instance `FOSRestBundle`_, `JMSI18nRoutingBundle`_, `KnpRadBundle`_ and `SonataAdminBundle`_. Loading Routes -------------- The routes in a Symfony application are loaded by the :class:`Symfony\\Bundle\\FrameworkBundle\\Routing\\DelegatingLoader`. This loader uses several other loaders (delegates) to load resources of different types, for instance YAML files or ``@Route`` annotations in controller files. The specialized loaders implement :class:`Symfony\\Component\\Config\\Loader\\LoaderInterface` and therefore have two important methods: :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::supports` and :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::load`. Take these lines from the ``routes.yaml``: .. configuration-block:: .. code-block:: yaml # config/routes.yaml controllers: resource: ../src/Controller/ type: annotation .. code-block:: xml .. code-block:: php // config/routes.php use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator; return function (RoutingConfigurator $routes) { $routes->import('../src/Controller', 'annotation'); }; When the main loader parses this, it tries all registered delegate loaders and calls their :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::supports` method with the given resource (``../src/Controller/``) and type (``annotation``) as arguments. When one of the loader returns ``true``, its :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::load` method will be called, which should return a :class:`Symfony\\Component\\Routing\\RouteCollection` containing :class:`Symfony\\Component\\Routing\\Route` objects. .. note:: Routes loaded this way will be cached by the Router the same way as when they are defined in one of the default formats (e.g. XML, YAML, PHP file). Loading Routes with a Custom Service ------------------------------------ Using a regular Symfony service is the simplest way to load routes in a customized way. It's much easier than creating a full custom route loader, so you should always consider this option first. To do so, define ``type: service`` as the type of the loaded routing resource and configure the service and method to call: .. configuration-block:: .. code-block:: yaml # config/routes.yaml admin_routes: resource: 'admin_route_loader::loadRoutes' type: service .. code-block:: xml .. code-block:: php // config/routes.php use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator; return function (RoutingConfigurator $routes) { $routes->import('admin_route_loader::loadRoutes', 'service'); }; In this example, the routes are loaded by calling the ``loadRoutes()`` method of the service whose ID is ``admin_route_loader``. Your service doesn't have to extend or implement any special class, but the called method must return a :class:`Symfony\\Component\\Routing\\RouteCollection` object. If you're using :ref:`autoconfigure `, your class should implement the :class:`Symfony\\Bundle\\FrameworkBundle\\Routing\\RouteLoaderInterface` interface to be tagged automatically. If you're **not using autoconfigure**, tag it manually with ``routing.route_loader``. .. note:: The routes defined using service route loaders will be automatically cached by the framework. So whenever your service should load new routes, don't forget to clear the cache. .. tip:: If your service is invokable, you don't need to precise the method to use. Creating a custom Loader ------------------------ To load routes from some custom source (i.e. from something other than annotations, YAML or XML files), you need to create a custom route loader. This loader has to implement :class:`Symfony\\Component\\Config\\Loader\\LoaderInterface`. In most cases it is easier to extend from :class:`Symfony\\Component\\Config\\Loader\\Loader` instead of implementing :class:`Symfony\\Component\\Config\\Loader\\LoaderInterface` yourself. The sample loader below supports loading routing resources with a type of ``extra``. The type name should not clash with other loaders that might support the same type of resource. Make up any name specific to what you do. The resource name itself is not actually used in the example:: // src/Routing/ExtraLoader.php namespace App\Routing; use Symfony\Component\Config\Loader\Loader; use Symfony\Component\Routing\Route; use Symfony\Component\Routing\RouteCollection; class ExtraLoader extends Loader { private $isLoaded = false; public function load($resource, string $type = null) { if (true === $this->isLoaded) { throw new \RuntimeException('Do not add the "extra" loader twice'); } $routes = new RouteCollection(); // prepare a new route $path = '/extra/{parameter}'; $defaults = [ '_controller' => 'App\Controller\ExtraController::extra', ]; $requirements = [ 'parameter' => '\d+', ]; $route = new Route($path, $defaults, $requirements); // add the new route to the route collection $routeName = 'extraRoute'; $routes->add($routeName, $route); $this->isLoaded = true; return $routes; } public function supports($resource, string $type = null) { return 'extra' === $type; } } Make sure the controller you specify really exists. In this case you have to create an ``extra()`` method in the ``ExtraController``:: // src/Controller/ExtraController.php namespace App\Controller; use Symfony\Bundle\FrameworkBundle\Controller\AbstractController; use Symfony\Component\HttpFoundation\Response; class ExtraController extends AbstractController { public function extra($parameter) { return new Response($parameter); } } Now define a service for the ``ExtraLoader``: .. configuration-block:: .. code-block:: yaml # config/services.yaml services: # ... App\Routing\ExtraLoader: tags: [routing.loader] .. code-block:: xml .. code-block:: php // config/services.php use App\Routing\ExtraLoader; $container->autowire(ExtraLoader::class) ->addTag('routing.loader') ; Notice the tag ``routing.loader``. All services with this *tag* will be marked as potential route loaders and added as specialized route loaders to the ``routing.loader`` *service*, which is an instance of :class:`Symfony\\Bundle\\FrameworkBundle\\Routing\\DelegatingLoader`. Using the Custom Loader ~~~~~~~~~~~~~~~~~~~~~~~ If you did nothing else, your custom routing loader would *not* be called. What remains to do is adding a few lines to the routing configuration: .. configuration-block:: .. code-block:: yaml # config/routes.yaml app_extra: resource: . type: extra .. code-block:: xml .. code-block:: php // config/routes.php use Symfony\Component\Routing\Loader\Configurator\RoutingConfigurator; return function (RoutingConfigurator $routes) { $routes->import('.', 'extra'); }; The important part here is the ``type`` key. Its value should be ``extra`` as this is the type which the ``ExtraLoader`` supports and this will make sure its ``load()`` method gets called. The ``resource`` key is insignificant for the ``ExtraLoader``, so it is set to ``.`` (a single dot). .. note:: The routes defined using custom route loaders will be automatically cached by the framework. So whenever you change something in the loader class itself, don't forget to clear the cache. More Advanced Loaders --------------------- If your custom route loader extends from :class:`Symfony\\Component\\Config\\Loader\\Loader` as shown above, you can also make use of the provided resolver, an instance of :class:`Symfony\\Component\\Config\\Loader\\LoaderResolver`, to load secondary routing resources. You still need to implement :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::supports` and :method:`Symfony\\Component\\Config\\Loader\\LoaderInterface::load`. Whenever you want to load another resource - for instance a YAML routing configuration file - you can call the :method:`Symfony\\Component\\Config\\Loader\\Loader::import` method:: // src/Routing/AdvancedLoader.php namespace App\Routing; use Symfony\Component\Config\Loader\Loader; use Symfony\Component\Routing\RouteCollection; class AdvancedLoader extends Loader { public function load($resource, string $type = null) { $routes = new RouteCollection(); $resource = '@ThirdPartyBundle/Resources/config/routes.yaml'; $type = 'yaml'; $importedRoutes = $this->import($resource, $type); $routes->addCollection($importedRoutes); return $routes; } public function supports($resource, string $type = null) { return 'advanced_extra' === $type; } } .. note:: The resource name and type of the imported routing configuration can be anything that would normally be supported by the routing configuration loader (YAML, XML, PHP, annotation, etc.). .. note:: For more advanced uses, check out the `ChainRouter`_ provided by the Symfony CMF project. This router allows applications to use two or more routers combined, for example to keep using the default Symfony routing system when writing a custom router. .. _`FOSRestBundle`: https://github.com/FriendsOfSymfony/FOSRestBundle .. _`JMSI18nRoutingBundle`: https://github.com/schmittjoh/JMSI18nRoutingBundle .. _`KnpRadBundle`: https://github.com/KnpLabs/KnpRadBundle .. _`SonataAdminBundle`: https://github.com/sonata-project/SonataAdminBundle .. _`ChainRouter`: https://symfony.com/doc/current/cmf/components/routing/chain.html