How to Optimize your Development Environment for Debugging

Disabling the Bootstrap File and Class Caching

And to make the production environment as fast as possible, Symfony creates big PHP files in your cache containing the aggregation of PHP classes your project needs for every request. However, this behavior can confuse your debugger, because the same class can be located in two different places: the original class file and the big file which aggregates lots of classes.

This recipe shows you how you can tweak this caching mechanism to make it friendlier when you need to debug code that involves Symfony classes.

The app_dev.php front controller reads as follows by default:

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// ...

$loader = require_once __DIR__.'/../app/bootstrap.php.cache';
require_once __DIR__.'/../app/AppKernel.php';

$kernel = new AppKernel('dev', true);
$kernel->loadClassCache();
$request = Request::createFromGlobals();

To make your debugger happier, disable the loading of all PHP class caches by removing the call to loadClassCache() and by replacing the require statements like below:

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// ...

// $loader = require_once __DIR__.'/../app/bootstrap.php.cache';
$loader = require_once __DIR__.'/../app/autoload.php';
require_once __DIR__.'/../app/AppKernel.php';

$kernel = new AppKernel('dev', true);
// $kernel->loadClassCache();
$request = Request::createFromGlobals();

Some IDEs do not like the fact that some classes are stored in different locations. To avoid problems, you can either tell your IDE to ignore the PHP cache files, or you can change the extension used by Symfony for these files:

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$kernel->loadClassCache('classes', '.php.cache');

Useful Debugging Commands

When developing a large application, it can be hard to keep track of all the different services, routes and translations. Luckily, Symfony has some commands that can help you visualize and find the information.

debug:container

Displays information about the contents of the Symfony container for all public services. To find only those matching a name, append the name as an argument.

debug:config

Shows all configured bundles, their class and their alias.

debug:event-dispatcher

Displays information about all the registered listeners in the event dispatcher.

debug:router

Displays information about all configured routes in the application as a table with the name, method, scheme, host and path for each route.

debug:translation <locale>

Shows a table of the translation key, the domain, the translation and the fallback translation for all known messages, if translations exist for the given locale.