This tutorial has a new version, check it out!

Web Debug Toolbar and Profiler

Keep on Learning!

If you liked what you've learned so far, dive in!
Subscribe to get access to this tutorial plus
video, code and script downloads.

Start your All-Access Pass
Buy just this tutorial for $10.00

Right now, there's no floating web debug toolbar on our pages. That's one of the best features of Symfony, and so I want it in my micro-edition too.

Instead of getting a lot of features automatically, we need to enable things one-by-one when and if we need them. The same is true for the web debug toolbar: it comes from the WebProfilerBundle. This lives in our project, but it's not enabled yet. Add it in AppKernel down below the others:

27 lines AppKernel.php
... lines 1 - 5
class AppKernel extends Kernel
{
public function registerBundles()
{
... lines 10 - 16
$bundles[] = new \Symfony\Bundle\WebProfilerBundle\WebProfilerBundle();
... lines 18 - 19
}
... lines 21 - 25
}

Next, head into config.yml - we need a little bit of configuration. Add a web_profiler key with a toolbar option. Set this to %kernel.debug%:

... lines 1 - 9
web_profiler:
toolbar: %kernel.debug%

That's a special parameter that's equal to the debug argument we pass to AppKernel in index.php:

24 lines web/index.php
... lines 1 - 8
$debug = true;
... lines 10 - 17
$kernel = new AppKernel($env, $debug);
... lines 19 - 24

Mostly, this flag is used to hide or show errors. But for now, we'll also use it to decide if the web debug toolbar should show up or not.

Also, under framework, add a profiler key with an enabled option that we'll also set to %kernel.debug%:

framework:
... lines 2 - 6
profiler:
enabled: %kernel.debug%
... lines 9 - 12

We have debug set to true, so try it! No toolbar yet - just this nice error:

Unable to generate a URL for the named route "_wdt" as such
route does not exist.

This is the error you usually get if you're generating a URL to a route, but you're using a bad route name. The web debug toolbar and profiler are fueled by real Symfony routes, and those routes need to be included for this all to work. On the Standard Edition, I already have the app/config/routing_dev.yml file open, because we need to copy the top two entries. Find config/routing.yml and paste those there:

... lines 1 - 4
_wdt:
resource: "@WebProfilerBundle/Resources/config/routing/wdt.xml"
prefix: /_wdt
_profiler:
resource: "@WebProfilerBundle/Resources/config/routing/profiler.xml"
prefix: /_profiler

Try one more time. There's the toolbar, with all of the goods we love.

Leave a comment!

What PHP libraries does this tutorial use?

// composer.json
{
    "require": {
        "symfony/symfony": "^2.7", // v2.7.2
        "sensio/framework-extra-bundle": "^3.0", // v3.0.9
        "vlucas/phpdotenv": "^2.0", // v2.0.1
        "symfony/monolog-bundle": "^2.7" // v2.7.1
    }
}