title: advanced / dynamic permissions on sfguard - symfony
body: <p>I have a symfony project and would like to add communities feature.</p>
  
  <p>Everyone can open a community as an admin and invites people to join the community.</p>
  
  <p>Admin has more permissions than a regular community user.</p>
  
  <p>The thing is, I want to user Syfony's sfguarduser, sfguardgroup, sfguardpermission</p>
  
  <ol>
  <li>Does it make any sense to use the sfguard architecture for that purpose?</li>
  <li>how do I check if a specific user has a spcecific permission on a specific group?</li>
  </ol>