after.php

<?php

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Security\Http\AccessMapInterface;

class DelegatingAccessMap implements AccessMapInterface
{
    /**
     * @var array A map of path prefix to delegate map
     */
    private $map = array();

    /**
     * @var AccessMap The default access map
     */
    private $defaultMap;

    public function addMap($prefix, AccessMapInterface $map)
    {
        if (empty($prefix)) {
            throw new \InvalidArgumentException('Prefix cannot be empty');
        }

        $this->map[$prefix] = $map;
    }

    public function setDefaultMap(AccessMapInterface $map)
    {
        $this->defaultMap = $map;
    }

    public function getPatterns(Request $request)
    {
        foreach ($this->map as $prefix => $map) {
            if (0 === strpos($request->getPathInfo(), $prefix)) {
                return $map->getPatterns($request);
            }
        }

        if (null !== $this->defaultMap) {
            return $this->defaultMap->getPatterns($request);
        }

        return array(null, null);
    }
}

before.php

<?php

use Symfony\Component\HttpFoundation\Request;
use Symfony\Component\Security\Http\AccessMap;

class DelegatingAccessMap extends AccessMap
{
    /**
     * @var array A map of path prefix to delegate map
     */
    private $map = array();

    /**
     * @var AccessMap The default access map
     */
    private $defaultMap;

    public function addMap($prefix, AccessMap $map)
    {
        if (empty($prefix)) {
            throw new \InvalidArgumentException('Prefix cannot be empty');
        }

        $this->map[$prefix] = $map;
    }

    public function setDefaultMap(AccessMap $map)
    {
        $this->defaultMap = $map;
    }

    public function getPatterns(Request $request)
    {
        foreach ($this->map as $prefix => $map) {
            if (0 === strpos($request->getPathInfo(), $prefix)) {
                return $map->getPatterns($request);
            }
        }

        if (null !== $this->defaultMap) {
            return $this->defaultMap->getPatterns($request);
        }

        return array(null, null);
    }
}