Q:

How to hide some pages from users and only show it to Admin ? 

I have installed the Activ Admin gem but not sure it will be of any help.  I have some pages which I want to hide from being seen by anonymous and some from logged in users too.  How can I do it ?  
I am sure there must be ACL gems in RoR but I am not sure which is the standard and preferred way to do it ?  any help ?  Thanks

A:

I'm not familiar with Active Admin but,
assuming you already have a way of determining if a user is logged in (and you have a way to address the current_user), you could simply do the following:
in your controller (or in your sessionshelper for example)
def admin_users_only
  unless current_user.admin?  redirect_to "wherever you want to redirect to"
end

in the same controller
before_filter :admin_users_only, only: [:index, :or, :any, :other]

(of course your user model needs an admin attribute)

