Symfony2 security

security:
    encoders:
        Web\UserBundle\Entity\User:
            algorithm: bcrypt
            cost: 12

    providers:
        chain_provider:
            chain:
                providers: [user_db]
        user_db:
            entity: { class: WebUserBundle:User, property: username }

    firewalls:
        secured_area:
            anonymous: ~
            pattern:    ^/
            http_basic: ~
            form_login:
                login_path: login
                check_path: login_check	
                default_target_path: /
            logout:
                path:   /logout
                target: /

    role_hierarchy:
        ROLE_ADMIN:       ROLE_USER
        ROLE_SUPER_ADMIN: [ ROLE_ADMIN, ROLE_ALLOWED_TO_SWITCH ]

    access_control:
        - { path: ^/edit, roles: ROLE_ADMIN }