Example of a Service Locator

UserRepository.php

<?php

class UserRepository  
{
    public function __construct(Container $container)
    {
        $this->container = $container;
    }

    public function getUser($id)
    {
        $db = $this->container->get('db');
        // ...
    }
}

Taken from http://shadowhand.me/dependency-injection-with-auryn/