Service Container

Introduction#

A Symfony application is typically composed of a lot of objects that perform different tasks, such as repositories, controllers, mailers, etc. In Symfony, these objects are called services, and are defined in app/config/services.yml or in one of the installed bundles.

The Service Container knows how to instantiate these services, and keeps a reference of them so they don’t have to be instantiated twice. If a service has dependencies it will instantiate those too.

Retrieve a service from the container

$logger = $container->get('logger');

This will fetch the service with the service ID “logger” from the container, an object that implements Psr\Log\LoggerInterface.