symfony 4 : How to get "/public" from RootDir

It is a bad practice to inject the whole container, just to access parameters, if you are not in a controller. Just auto wire the ParameterBagInterface like this,

protected $parameterBag; public function __construct(ParameterBagInterface $parameterBag) { $this->parameterBag = $parameterBag; } 

and then access your parameter like this (in this case the project directory),

$this->parameterBag->get('kernel.project_dir'); 

Hope someone will find this helpful.

Cheers.

In Controller (also with inheriting AbstractController):

$projectDir = $this->getParameter('kernel.project_dir'); 

In config/services.yaml:

parameters: webDir: '%env(DOCUMENT_ROOT)%' 

In your controller:

use Symfony\Component\DependencyInjection\ParameterBag\ParameterBagInterface; ... public function yourFunction(Parameterbag $parameterBag) { $webPath = $parameterBag->get('webDir') } 

If you need to access a directory within public, change the last line to the following:

$webPath = $parameterBag->get('webDir') . '/your/path/from/the/public/dir/' 

You can inject KernelInterface to the service or whatever and then get the project directory with $kernel->getProjectDir():

<?php namespace App\Service; use Symfony\Component\HttpKernel\KernelInterface; class Foo { protected $projectDir; public function __construct(KernelInterface $kernel) { $this->projectDir = $kernel->getProjectDir(); } public function showProjectDir() { echo "This is the project directory: " . $this->projectDir; } } 

All above answers seems valid, but I think it's simplier if you configure it as parameter in services.yaml

If you need to use it in serveral services, you can bind it like this:

# services.yaml services: _defaults: autowire: true autoconfigure: true bind: $publicDir: "%kernel.project_dir%/public" 

# src/Services/MyService.php class MyService { public function __construct( private string $publicDir, ) { } // … } 

This way, this is configured at one place only, and if later you decide to change /public to something else, you will have to change it only in .yaml file.

If you don't need the root directory but a subdirectory, it might be better to define the final target path: This way you will be more flexible if you need later to move only that directory, like $imageDir or $imagePath (depends if you will use the full directory or only the public path).

Note also the default public path is defined in composer.json file, in the extra.public-dir key

edit mai 2025:

In latest Symfony version (since 6.1), you can also use the #[Autowire] attribute. So you can use parameters section in a yaml file to define for example public_dir , and inject it in your service. Depending of your needs / usages you might prefer this:

# config/services.yaml parameters: public_dir: 'public' services: … 

# src/Services/MyService.php class MyService { private string $publicPath; public function __construct( #[Autowire(param: 'kernel.project_dir')] string $rootDir, #[Autowire(param: 'public_dir')] string $publicDir, ) { $this->publicPath = realpath($rootDir . DIRECTORY_SEPARATOR . $publicDir); } // … } 

Starting from Symfony 4.3 we can generate absolute (and relative) URLs for a given path by using the two methods getAbsoluteUrl() and getRelativePath() of the new Symfony\Component\HttpFoundation\UrlHelper class.

New in Symfony 4.3: URL Helper

public function someControllerAction(UrlHelper $urlHelper) { // ... return [ 'avatar' => $urlHelper->getAbsoluteUrl($user->avatar()->path()), // ... ]; }