Add Routes Middlewares

doc/usage.rst

@@ -352,6 +352,63 @@ object that is returned by the routing methods::
     It only makes sense to name routes if you use providers that make use
     of the ``RouteCollection``.
 
+Routes middlewares
+~~~~~~~~~~~~~~~~~~
+
+You can define one or more Routes Middlewares, and link them to your routes.
+Routes Middlewares are just "PHP callables" (i.e. a Closure or a
+"ClassName::methodName" string, like others Silex callbacks), which will
+be triggered when their route is matched.
+Middlewares are fired just before the route callback,
+but after Application ``before`` filters, which have precedence
+ - see next section about these ``before`` filters.
+
+This mechanism can be used for a lot of use case - for example, a
+"anonymous/logged user" simple control::
+
+    $mustBeAnonymous = function (Request $request) use ($app) {
+        if ($app['session']->has('userId')) {
+            return $app->redirect('/user/logout');
+        }
+    };
+
+    $mustBeLogged = function (Request $request) use ($app) {
+        if (!$app['session']->has('userId')) {
+            return $app->redirect('/user/login');
+        }
+    };
+
+    $app->get('/user/subscribe', function () {
+        ...
+    })
+    ->middleware($mustBeAnonymous);
+
+    $app->get('/user/login', function () {
+        ...
+    })
+    ->middleware($mustBeAnonymous);
+
+    $app->get('/user/my-profile', function () {
+        ...
+    })
+    ->middleware($mustBeLogged);
+
+You can call the ``middleware`` function several times for a single route.
+The middlewares will be triggered in the order you added them to the route.
+
+For convenience, the routes middlewares functions are triggered with the current
+Request as their only argument.
+
+If any of the routes middlewares returns a Symfony Http Response, this response
+will short-circuit the whole rendering : the next middlewares won't run, neither
+the route callback.
+As in route callbacks, you can redirect to another page by from a route middleware
+by returning a redirect response, which you can create by calling the
+Application ``redirect`` method.
+
+A route Middleware can return a Symfony Http Response or null.
+A RuntimeException will be thrown if anything else is returned.
+
 Before and after filters
 ------------------------
 

src/Silex/Application.php

@@ -111,6 +111,18 @@ class Application extends \Pimple implements HttpKernelInterface, EventSubscribe
             return new RedirectableUrlMatcher($app['routes'], $app['request_context']);
         });
 
+        $this['route_middlewares_trigger'] = $this->protect(function (KernelEvent $event) use ($app) {
+            foreach ($event->getRequest()->attributes->get('_middlewares', array()) as $callback) {
+                $ret = call_user_func($callback, $event->getRequest());
+                if ($ret instanceof Response) {
+                    $event->setResponse($ret);
+                    return;
+                } elseif (null !== $ret) {
+                    throw new \RuntimeException('Middleware for route "'.$event->getRequest()->attributes->get('_route').'" returned an invalid response value. Must return null or an instance of Response.');
+                }
+            }
+        });
+
         $this['request.default_locale'] = 'en';
 
         $this['request'] = function () {
@@ -409,6 +421,7 @@ class Application extends \Pimple implements HttpKernelInterface, EventSubscribe
         if (HttpKernelInterface::MASTER_REQUEST === $event->getRequestType()) {
             $this->beforeDispatched = true;
             $this['dispatcher']->dispatch(SilexEvents::BEFORE, $event);
+            $this['route_middlewares_trigger']($event);
         }
     }
 

src/Silex/Controller.php

@@ -154,6 +154,22 @@ class Controller
         return $this;
     }
 
+    /**
+     * Sets a callback to handle before triggering the route callback.
+     * (a.k.a. "Route Middleware")
+     *
+     * @param mixed  $callback A PHP callback to be triggered when the Route is matched, just before the route callback
+     * @return Controller $this The current Controller instance
+     */
+    public function middleware($callback)
+    {
+        $middlewareCallbacks = $this->route->getDefault('_middlewares');
+        $middlewareCallbacks[] = $callback;
+        $this->route->setDefault('_middlewares', $middlewareCallbacks);
+
+        return $this;
+    }
+
     /**
      * Freezes the controller.
      *

tests/Silex/Tests/ApplicationTest.php

@@ -15,6 +15,9 @@ use Silex\Application;
 
 use Symfony\Component\HttpFoundation\Request;
 use Symfony\Component\HttpKernel\Exception\HttpException;
+use Symfony\Component\HttpFoundation\Response;
+use Symfony\Component\HttpFoundation\RedirectResponse;
+use Symfony\Component\HttpKernel\HttpKernelInterface;
 
 /**
  * Application test cases.
@@ -166,6 +169,120 @@ class ApplicationTest extends \PHPUnit_Framework_TestCase
         $this->assertEquals('text/html; charset=ISO-8859-1', $response->headers->get('Content-Type'));
     }
 
+    public function testRoutesMiddlewares()
+    {
+        $app = new Application();
+
+        $test = $this;
+
+        $middlewareTarget = array();
+        $middleware1 = function (Request $request) use (&$middlewareTarget, $test) {
+            $test->assertEquals('/reached', $request->getRequestUri());
+            $middlewareTarget[] = 'middleware1_triggered';
+        };
+        $middleware2 = function (Request $request) use (&$middlewareTarget, $test) {
+            $test->assertEquals('/reached', $request->getRequestUri());
+            $middlewareTarget[] = 'middleware2_triggered';
+        };
+        $middleware3 = function (Request $request) use (&$middlewareTarget, $test) {
+            throw new \Exception('This middleware shouldn\'t run!');
+        };
+
+        $app->get('/reached', function () use (&$middlewareTarget) {
+            $middlewareTarget[] = 'route_triggered';
+            return 'hello';
+        })
+        ->middleware($middleware1)
+        ->middleware($middleware2);
+
+        $app->get('/never-reached', function () use (&$middlewareTarget) {
+            throw new \Exception('This route shouldn\'t run!');
+        })
+        ->middleware($middleware3);
+
+        $result = $app->handle(Request::create('/reached'));
+
+        $this->assertSame(array('middleware1_triggered', 'middleware2_triggered', 'route_triggered'), $middlewareTarget);
+        $this->assertEquals('hello', $result->getContent());
+    }
+
+    public function testRoutesMiddlewaresWithResponseObject()
+    {
+        $app = new Application();
+
+        $app->get('/foo', function () {
+            throw new \Exception('This route shouldn\'t run!');
+        })
+        ->middleware(function () {
+            return new Response('foo');
+        });
+
+        $request = Request::create('/foo');
+        $result = $app->handle($request);
+
+        $this->assertEquals('foo', $result->getContent());
+    }
+
+    public function testRoutesMiddlewaresWithRedirectResponseObject()
+    {
+        $app = new Application();
+
+        $app->get('/foo', function () {
+            throw new \Exception('This route shouldn\'t run!');
+        })
+        ->middleware(function () use ($app) {
+            return $app->redirect('/bar');
+        });
+
+        $request = Request::create('/foo');
+        $result = $app->handle($request);
+
+        $this->assertInstanceOf('Symfony\Component\HttpFoundation\RedirectResponse', $result);
+        $this->assertEquals('/bar', $result->getTargetUrl());
+    }
+
+    public function testRoutesMiddlewaresTriggeredAfterSilexBeforeFilters()
+    {
+        $app = new Application();
+
+        $middlewareTarget = array();
+        $middleware = function (Request $request) use (&$middlewareTarget) {
+            $middlewareTarget[] = 'middleware_triggered';
+        };
+
+        $app->get('/foo', function () use (&$middlewareTarget) {
+            $middlewareTarget[] = 'route_triggered';
+        })
+        ->middleware($middleware);
+
+        $app->before(function () use (&$middlewareTarget) {
+            $middlewareTarget[] = 'before_triggered';
+        });
+
+        $app->handle(Request::create('/foo'));
+
+        $this->assertSame(array('before_triggered', 'middleware_triggered', 'route_triggered'), $middlewareTarget);
+    }
+
+    /**
+     * @expectedException RuntimeException
+     */
+    public function testNonResponseAndNonNullReturnFromRouteMiddlewareShouldThrowRuntimeException()
+    {
+        $app = new Application();
+
+        $middleware = function (Request $request) {
+            return 'string return';
+        };
+
+        $app->get('/', function () {
+            return 'hello';
+        })
+        ->middleware($middleware);
+
+        $app->handle(Request::create('/'), HttpKernelInterface::MASTER_REQUEST, false);
+    }
+
     /**
      * @expectedException RuntimeException
      */