From 1c297009ab137460b09311c41f1bbbe7c88324a3 Mon Sep 17 00:00:00 2001
From: Javier Eguiluz <javier.eguiluz@gmail.com>
Date: Mon, 28 May 2018 16:33:03 +0200
Subject: [PATCH] Explain how to check if a route exists

---
 components/routing.rst | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/components/routing.rst b/components/routing.rst
index b1690cce6bf..21c706e267c 100644
--- a/components/routing.rst
+++ b/components/routing.rst
@@ -229,6 +229,28 @@ a certain route::
     of the current :class:`Symfony\\Component\\Routing\\RequestContext` does
     not match the requirement.
 
+Check if a Route Exists
+~~~~~~~~~~~~~~~~~~~~~~~
+
+In highly dynamic applications, it may be necessary to check whether a route
+exists before using it to generate a URL. In those cases, don't use the
+:method:`Symfony\\Component\\Routing\\Router::getRouteCollection` method because
+that regenerates the routing cache and slows down the application.
+
+Instead, try to generate the URL and catch the
+:class:`Symfony\\Component\\Routing\\Exception\\RouteNotFoundException` thrown
+when the route doesn't exist::
+
+    use Symfony\Component\Routing\Exception\RouteNotFoundException;
+
+    // ...
+
+    try {
+        $url = $generator->generate($dynamicRouteName, $parameters);
+    } catch (RouteNotFoundException $e) {
+        // the route is not defined...
+    }
+
 Load Routes from a File
 ~~~~~~~~~~~~~~~~~~~~~~~