Routing

Routing Examples

A route is a map from a URL path to a controller. For example, suppose you want to match any URL like /blog/my-post or /blog/all-about-symfony and send it to a controller that can look up and render that blog post. The route is simple:

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// src/AppBundle/Controller/BlogController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;

class BlogController extends Controller
{
    /**
     * Matches /blog exactly
     *
     * @Route("/blog", name="blog_list")
     */
    public function listAction()
    {
        // ...
    }

    /**
     * Matches /blog/*
     *
     * @Route("/blog/{slug}", name="blog_show")
     */
    public function showAction($slug)
    {
        // $slug will equal the dynamic part of the URL
        // e.g. at /blog/yay-routing, then $slug='yay-routing'

        // ...
    }
}

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# app/config/routing.yml
blog_list:
    path:     /blog
    defaults: { _controller: AppBundle:Blog:list }

blog_show:
    path:     /blog/{slug}
    defaults: { _controller: AppBundle:Blog:show }

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<!-- app/config/routing.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing
        http://symfony.com/schema/routing/routing-1.0.xsd">

    <route id="blog_list" path="/blog">
        <default key="_controller">AppBundle:Blog:list</default>
    </route>

    <route id="blog_show" path="/blog/{slug}">
        <default key="_controller">AppBundle:Blog:show</default>
    </route>
</routes>

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// app/config/routing.php
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\Route;

$routes = new RouteCollection();
$routes->add('blog_list', new Route('/blog', array(
    '_controller' => 'AppBundle:Blog:list',
)));
$routes->add('blog_show', new Route('/blog/{slug}', array(
    '_controller' => 'AppBundle:Blog:show',
)));

return $routes;

Thanks to these two routes:

• If the user goes to /blog, the first route is matched and listAction() is executed;
• If the user goes to /blog/*, the second route is matched and showAction() is executed. Because the route path is /blog/{slug}, a $slug variable is passed to showAction() matching that value. For example, if the user goes to /blog/yay-routing, then $slug will equal yay-routing.

Whenever you have a {placeholder} in your route path, that portion becomes a wildcard: it matches any value. Your controller can now also have an argument called $placeholder (the wildcard and argument names must match).

Each route also has an internal name: blog_list and blog_show. These can be anything (as long as each is unique) and don't have any meaning yet. Later, you'll use it to generate URLs.

This is the goal of the Symfony router: to map the URL of a request to a controller. Along the way, you'll learn all sorts of tricks that make mapping even the most complex URLs easy.

Adding {wildcard} Requirements

Imagine the blog_list route will contain a paginated list of blog posts, with URLs like /blog/2 and /blog/3 for pages 2 and 3. If you change the route's path to /blog/{page}, you'll have a problem:

• blog_list: /blog/{page} will match /blog/*;
• blog_show: /blog/{slug} will also match /blog/*.

When two routes match the same URL, the first route that's loaded wins. Unfortunately, that means that /blog/yay-routing will match the blog_list. No good!

To fix this, add a requirement that the {page} wildcard can only match numbers (digits):

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// src/AppBundle/Controller/BlogController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;

class BlogController extends Controller
{
    /**
     * @Route("/blog/{page}", name="blog_list", requirements={"page"="\d+"})
     */
    public function listAction($page)
    {
        // ...
    }

    /**
     * @Route("/blog/{slug}", name="blog_show")
     */
    public function showAction($slug)
    {
        // ...
    }
}

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# app/config/routing.yml
blog_list:
    path:      /blog/{page}
    defaults:  { _controller: AppBundle:Blog:list }
    requirements:
        page: '\d+'

blog_show:
    # ...

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<!-- app/config/routing.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing
        http://symfony.com/schema/routing/routing-1.0.xsd">

    <route id="blog_list" path="/blog/{page}">
        <default key="_controller">AppBundle:Blog:list</default>
        <requirement key="page">\d+</requirement>
    </route>

    <!-- ... -->
</routes>

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// app/config/routing.php
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\Route;

$routes = new RouteCollection();
$routes->add('blog_list', new Route('/blog/{page}', array(
    '_controller' => 'AppBundle:Blog:list',
), array(
    'page' => '\d+'
)));

// ...

return $routes;

The \d+ is a regular expression that matches a digit of any length. Now:

To learn about other route requirements - like HTTP method, hostname and dynamic expressions - see How to Define Route Requirements.

Giving {placeholders} a Default Value

In the previous example, the blog_list has a path of /blog/{page}. If the user visits /blog/1, it will match. But if they visit /blog, it will not match. As soon as you add a {placeholder} to a route, it must have a value.

So how can you make blog_list once again match when the user visits /blog? By adding a default value:

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// src/AppBundle/Controller/BlogController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;
use Sensio\Bundle\FrameworkExtraBundle\Configuration\Route;

class BlogController extends Controller
{
    /**
     * @Route("/blog/{page}", name="blog_list", requirements={"page"="\d+"})
     */
    public function listAction($page = 1)
    {
        // ...
    }
}

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# app/config/routing.yml
blog_list:
    path:      /blog/{page}
    defaults:  { _controller: AppBundle:Blog:list, page: 1 }
    requirements:
        page: '\d+'

blog_show:
    # ...

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<!-- app/config/routing.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing
        http://symfony.com/schema/routing/routing-1.0.xsd">

    <route id="blog_list" path="/blog/{page}">
        <default key="_controller">AppBundle:Blog:list</default>
        <default key="page">1</default>

        <requirement key="page">\d+</requirement>
    </route>

    <!-- ... -->
</routes>

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// app/config/routing.php
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\Route;

$routes = new RouteCollection();
$routes->add('blog_list', new Route(
    '/blog/{page}',
    array(
        '_controller' => 'AppBundle:Blog:list',
        'page'        => 1,
    ),
    array(
        'page' => '\d+'
    )
));

// ...

return $routes;

Now, when the user visits /blog, the blog_list route will match and $page will default to a value of 1.

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// src/AppBundle/Controller/ArticleController.php

// ...
class ArticleController extends Controller
{
    /**
     * @Route(
     *     "/articles/{_locale}/{year}/{slug}.{_format}",
     *     defaults={"_format": "html"},
     *     requirements={
     *         "_locale": "en|fr",
     *         "_format": "html|rss",
     *         "year": "\d+"
     *     }
     * )
     */
    public function showAction($_locale, $year, $slug)
    {
    }
}

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# app/config/routing.yml
article_show:
  path:     /articles/{_locale}/{year}/{slug}.{_format}
  defaults: { _controller: AppBundle:Article:show, _format: html }
  requirements:
      _locale:  en|fr
      _format:  html|rss
      year:     \d+

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<!-- app/config/routing.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing
        http://symfony.com/schema/routing/routing-1.0.xsd">

    <route id="article_show"
        path="/articles/{_locale}/{year}/{slug}.{_format}">

        <default key="_controller">AppBundle:Article:show</default>
        <default key="_format">html</default>
        <requirement key="_locale">en|fr</requirement>
        <requirement key="_format">html|rss</requirement>
        <requirement key="year">\d+</requirement>

    </route>
</routes>

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// app/config/routing.php
use Symfony\Component\Routing\RouteCollection;
use Symfony\Component\Routing\Route;

$routes = new RouteCollection();
$routes->add(
    'article_show',
    new Route('/articles/{_locale}/{year}/{slug}.{_format}', array(
        '_controller' => 'AppBundle:Article:show',
        '_format'     => 'html',
    ), array(
        '_locale' => 'en|fr',
        '_format' => 'html|rss',
        'year'    => '\d+',
    ))
);

return $routes;

Controller Naming Pattern

If you use YAML, XML or PHP route configuration, then each route must have a _controller parameter, which dictates which controller should be executed when that route is matched. This parameter uses a simple string pattern called the logical controller name, which Symfony maps to a specific PHP method and class. The pattern has three parts, each separated by a colon:

bundle:controller:action

For example, a _controller value of AppBundle:Blog:show means:

The controller might look like this:

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// src/AppBundle/Controller/BlogController.php
namespace AppBundle\Controller;

use Symfony\Bundle\FrameworkBundle\Controller\Controller;

class BlogController extends Controller
{
    public function showAction($slug)
    {
        // ...
    }
}

Notice that Symfony adds the string Controller to the class name (Blog => BlogController) and Action to the method name (show => showAction()).

You could also refer to this controller using its fully-qualified class name and method: AppBundle\Controller\BlogController::showAction. But if you follow some simple conventions, the logical name is more concise and allows more flexibility.

Loading Routes

Symfony loads all the routes for your application from a single routing configuration file: app/config/routing.yml. But from inside of this file, you can load any other routing files you want. In fact, by default, Symfony loads annotation route configuration from your AppBundle's Controller/ directory, which is how Symfony sees our annotation routes:

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# app/config/routing.yml
app:
    resource: "@AppBundle/Controller/"
    type:     annotation

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<!-- app/config/routing.xml -->
<?xml version="1.0" encoding="UTF-8" ?>
<routes xmlns="http://symfony.com/schema/routing"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/routing
        http://symfony.com/schema/routing/routing-1.0.xsd">

    <!-- the type is required to enable the annotation reader for this resource -->
    <import resource="@AppBundle/Controller/" type="annotation"/>
</routes>

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// app/config/routing.php
use Symfony\Component\Routing\RouteCollection;

$routes = new RouteCollection();
$routes->addCollection(
    // second argument is the type, which is required to enable
    // the annotation reader for this resource
    $loader->import("@AppBundle/Controller/", "annotation")
);

return $routes;

For more details on loading routes, including how to prefix the paths of loaded routes, see How to Include External Routing Resources.

Generating URLs

The routing system should also be used to generate URLs. In reality, routing is a bidirectional system: mapping the URL to a controller and a route back to a URL.

To generate a URL, you need to specify the name of the route (e.g. blog_show) and any wildcards (e.g. slug = my-blog-post) used in the path for that route. With this information, any URL can easily be generated:

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class MainController extends Controller
{
    public function showAction($slug)
    {
        // ...

        // /blog/my-blog-post
        $url = $this->generateUrl(
            'blog_show',
            array('slug' => 'my-blog-post')
        );
    }
}

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$url = $this->container->get('router')->generate(
    'blog_show',
    array('slug' => 'my-blog-post')
);

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$this->get('router')->generate('blog', array(
    'page' => 2,
    'category' => 'Symfony',
));
// /blog/2?category=Symfony

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use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

$this->generateUrl('blog_show', array('slug' => 'my-blog-post'), UrlGeneratorInterface::ABSOLUTE_URL);
// http://www.example.com/blog/my-blog-post

Troubleshooting

Here are some common errors you might see while working with routing:

Controller "AppBundle\Controller\BlogController::showAction()" requires that you provide a value for the "$slug" argument.

This happens when your controller method has an argument (e.g. $slug):

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public function showAction($slug)
{
    // ..
}

But your route path does not have a {slug} wildcard (e.g. it is /blog/show). Add a {slug} to your route path: /blog/show/{slug} or give the argument a default value (i.e. $slug = null).

Some mandatory parameters are missing ("slug") to generate a URL for route "blog_show".

This means that you're trying to generate a URL to the blog_show route but you are not passing a slug value (which is required, because it has a {slug}) wildcard in the route path. To fix this, pass a slug value when generating the route:

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$this->generateUrl('blog_show', array('slug' => 'slug-value'));

// or, in Twig
// {{ path('blog_show', {'slug': 'slug-value'}) }}

Translating Routes

Symfony doesn't support defining routes with different contents depending on the user language. In those cases, you can define multiple routes per controller, one for each supported language; or use any of the bundles created by the community to implement this feature, such as JMSI18nRoutingBundle and BeSimpleI18nRoutingBundle.

Summary

Routing is a system for mapping the URL of incoming requests to the controller function that should be called to process the request. It both allows you to specify beautiful URLs and keeps the functionality of your application decoupled from those URLs. Routing is a bidirectional mechanism, meaning that it should also be used to generate URLs.

Keep Going!

Routing, check! Now, uncover the power of controllers.

Learn more about Routing