Database Switch Event Listener (Symfony2)

DatabaseSwitcherEventListener.php

<?php

namespace AppBundle\EventListener;

use Doctrine\DBAL\Connection;

class DatabaseSwitcherEventListener
{
    private $connection;

    public function __construct(Connection $connection)
    {
        $this->connection = $connection;
    }

    public function onKernelRequest()
    {
        $connection = $this->connection;
        if (!$connection->isConnected()) {
            $params = $this->connection->getParams();

            $params['dbname'] = getenv('SYMFONY__DATABASE__NAME') ? getenv('SYMFONY__DATABASE__NAME') : $params['dbname'];
            $connection->__construct(
                $params,
                $connection->getDriver(),
                $connection->getConfiguration(),
                $connection->getEventManager()
            );
            $connection->connect();
        }
    }
}

If you need to change default connection, providing a ENV variable