Allow switching/impersonating only to particular users in Symfony2

Question

EXPLANATION

Allowing user to switch to any other user is easy in Symfony2. My question is, how to allow certain user to switch only to certain other

Answer 1

You could possibly implement this type of thing by overriding the default SwitchUserListener.

The parameter you would override is: security.authentication.switchuser_listener.class

For example, in parameters.yml:

parameters:
  security.authentication.switchuser_listener.class: My\Project\Security\Listener\SwitchUserListener

Where, in your custom listener class, you'd implement Symfony\Component\Security\Http\Firewall\ListenerInterface and use the existing Symfony\Component\Security\Http\Firewall\SwitchUserListener class as a basis for your custom implementation.