Symfony
sponsored by SensioLabs
Menu
  • About
  • Documentation
  • Screencasts
  • Cloud
  • Certification
  • Community
  • Businesses
  • News
  • Download
  1. Home
  2. Documentation
  3. Create Framework
  4. The Routing Component
  • Documentation
  • Book
  • Reference
  • Bundles
  • Cloud
Search by Algolia

The Routing Component

Edit this page

The Routing Component

Before we start diving into the Routing component, let's refactor our current framework just a little to make templates even more readable:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
// example.com/web/front.php
require_once __DIR__.'/../vendor/autoload.php';

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;

$request = Request::createFromGlobals();

$map = [
    '/hello' => 'hello',
    '/bye'   => 'bye',
];

$path = $request->getPathInfo();
if (isset($map[$path])) {
    ob_start();
    extract($request->query->all(), EXTR_SKIP);
    include sprintf(__DIR__.'/../src/pages/%s.php', $map[$path]);
    $response = new Response(ob_get_clean());
} else {
    $response = new Response('Not Found', 404);
}

$response->send();

As we now extract the request query parameters, simplify the hello.php template as follows:

1
2
<!-- example.com/src/pages/hello.php -->
Hello <?= htmlspecialchars(isset($name) ? $name : 'World', ENT_QUOTES, 'UTF-8') ?>

Now, we are in good shape to add new features.

One very important aspect of any website is the form of its URLs. Thanks to the URL map, we have decoupled the URL from the code that generates the associated response, but it is not yet flexible enough. For instance, we might want to support dynamic paths to allow embedding data directly into the URL (e.g. /hello/Fabien) instead of relying on a query string (e.g. /hello?name=Fabien).

To support this feature, add the Symfony Routing component as a dependency:

1
$ composer require symfony/routing

Instead of an array for the URL map, the Routing component relies on a RouteCollection instance:

1
2
3
use Symfony\Component\Routing\RouteCollection;

$routes = new RouteCollection();

Let's add a route that describes the /hello/SOMETHING URL and add another one for the simple /bye one:

1
2
3
4
use Symfony\Component\Routing\Route;

$routes->add('hello', new Route('/hello/{name}', ['name' => 'World']));
$routes->add('bye', new Route('/bye'));

Each entry in the collection is defined by a name (hello) and a Route instance, which is defined by a route pattern (/hello/{name}) and an array of default values for route attributes (['name' => 'World']).

Note

Read the Routing documentation to learn more about its many features like URL generation, attribute requirements, HTTP method enforcement, loaders for YAML or XML files, dumpers to PHP or Apache rewrite rules for enhanced performance and much more.

Based on the information stored in the RouteCollection instance, a UrlMatcher instance can match URL paths:

1
2
3
4
5
6
7
8
use Symfony\Component\Routing\Matcher\UrlMatcher;
use Symfony\Component\Routing\RequestContext;

$context = new RequestContext();
$context->fromRequest($request);
$matcher = new UrlMatcher($routes, $context);

$attributes = $matcher->match($request->getPathInfo());

The match() method takes a request path and returns an array of attributes (notice that the matched route is automatically stored under the special _route attribute):

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
$matcher->match('/bye');
/* Result:
[
    '_route' => 'bye',
];
*/

$matcher->match('/hello/Fabien');
/* Result:
[
    'name' => 'Fabien',
    '_route' => 'hello',
];
*/

$matcher->match('/hello');
/* Result:
[
    'name' => 'World',
    '_route' => 'hello',
];
*/

Note

Even if we don't strictly need the request context in our examples, it is used in real-world applications to enforce method requirements and more.

The URL matcher throws an exception when none of the routes match:

1
2
3
$matcher->match('/not-found');

// throws a Symfony\Component\Routing\Exception\ResourceNotFoundException

With this knowledge in mind, let's write the new version of our framework:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
// example.com/web/front.php
require_once __DIR__.'/../vendor/autoload.php';

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\HttpFoundation\Response;
use Symfony\Component\Routing;

$request = Request::createFromGlobals();
$routes = include __DIR__.'/../src/app.php';

$context = new Routing\RequestContext();
$context->fromRequest($request);
$matcher = new Routing\Matcher\UrlMatcher($routes, $context);

try {
    extract($matcher->match($request->getPathInfo()), EXTR_SKIP);
    ob_start();
    include sprintf(__DIR__.'/../src/pages/%s.php', $_route);

    $response = new Response(ob_get_clean());
} catch (Routing\Exception\ResourceNotFoundException $exception) {
    $response = new Response('Not Found', 404);
} catch (Exception $exception) {
    $response = new Response('An error occurred', 500);
}

$response->send();

There are a few new things in the code:

  • Route names are used for template names;
  • 500 errors are now managed correctly;
  • Request attributes are extracted to keep our templates simple:
1
2
// example.com/src/pages/hello.php
Hello <?= htmlspecialchars($name, ENT_QUOTES, 'UTF-8') ?>
  • Route configuration has been moved to its own file:

    1
    2
    3
    4
    5
    6
    7
    8
    // example.com/src/app.php
    use Symfony\Component\Routing;
    
    $routes = new Routing\RouteCollection();
    $routes->add('hello', new Routing\Route('/hello/{name}', ['name' => 'World']));
    $routes->add('bye', new Routing\Route('/bye'));
    
    return $routes;

We now have a clear separation between the configuration (everything specific to our application in app.php) and the framework (the generic code that powers our application in front.php).

With less than 30 lines of code, we have a new framework, more powerful and more flexible than the previous one. Enjoy!

Using the Routing component has one big additional benefit: the ability to generate URLs based on Route definitions. When using both URL matching and URL generation in your code, changing the URL patterns should have no other impact. You can use the generator this way:

1
2
3
4
5
6
use Symfony\Component\Routing;

$generator = new Routing\Generator\UrlGenerator($routes, $context);

echo $generator->generate('hello', ['name' => 'Fabien']);
// outputs /hello/Fabien

The code should be self-explanatory; and thanks to the context, you can even generate absolute URLs:

1
2
3
4
5
6
7
8
use Symfony\Component\Routing\Generator\UrlGeneratorInterface;

echo $generator->generate(
    'hello',
    ['name' => 'Fabien'],
    UrlGeneratorInterface::ABSOLUTE_URL
);
// outputs something like http://example.com/somewhere/hello/Fabien

Tip

Concerned about performance? Based on your route definitions, create a highly optimized URL matcher class that can replace the default UrlMatcher:

1
2
3
4
5
6
7
8
use Symfony\Component\Routing\Matcher\CompiledUrlMatcher;
use Symfony\Component\Routing\Matcher\Dumper\CompiledUrlMatcherDumper;

// $compiledRoutes is a plain PHP array that describes all routes in a performant data format
// you can (and should) cache it, typically by exporting it to a PHP file
$compiledRoutes = (new CompiledUrlMatcherDumper($routes))->getCompiledRoutes();

$matcher = new CompiledUrlMatcher($compiledRoutes, $context);
Previous page The Front Controller
Next page Templating
This work, including the code samples, is licensed under a Creative Commons BY-SA 3.0 license.
We stand with Ukraine.
Version:

Symfony 5.4 is backed by

Measure & Improve Symfony Code Performance

Measure & Improve Symfony Code Performance

Peruse our complete Symfony & PHP solutions catalog for your web development needs.

Peruse our complete Symfony & PHP solutions catalog for your web development needs.

↓ Our footer now uses the colors of the Ukrainian flag because Symfony stands with the people of Ukraine.

Avatar of Damián Nohales, a Symfony contributor

Thanks Damián Nohales (@eagleoneraptor) for being a Symfony contributor

1 commit • 2 lines changed

View all contributors that help us make Symfony

Become a Symfony contributor

Be an active part of the community and contribute ideas, code and bug fixes. Both experts and newcomers are welcome.

Learn how to contribute

Symfony™ is a trademark of Symfony SAS. All rights reserved.

  • What is Symfony?
    • Symfony at a Glance
    • Symfony Components
    • Case Studies
    • Symfony Releases
    • Security Policy
    • Logo & Screenshots
    • Trademark & Licenses
    • symfony1 Legacy
  • Learn Symfony
    • Symfony Docs
    • Symfony Book
    • Reference
    • Bundles
    • Best Practices
    • Training
    • eLearning Platform
    • Certification
  • Screencasts
    • Learn Symfony
    • Learn PHP
    • Learn JavaScript
    • Learn Drupal
    • Learn RESTful APIs
  • Community
    • SymfonyConnect
    • Support
    • How to be Involved
    • Code of Conduct
    • Events & Meetups
    • Projects using Symfony
    • Downloads Stats
    • Contributors
    • Backers
  • Blog
    • Events & Meetups
    • A week of symfony
    • Case studies
    • Cloud
    • Community
    • Conferences
    • Diversity
    • Documentation
    • Living on the edge
    • Releases
    • Security Advisories
    • SymfonyInsight
    • Twig
    • SensioLabs
  • Services
    • SensioLabs services
    • Train developers
    • Manage your project quality
    • Improve your project performance
    • Host Symfony projects
    Deployed on
Follow Symfony
Search by Algolia