title: Add an Admin Role to the Devise's User Model
body: <p>I think my question is simple, I followed step by step the second option that appears on this page <a href="https://github.com/plataformatec/devise/wiki/How-To:-Add-an-Admin-Role" rel="nofollow">How To: Add an Admin Role</a>. Now I would like to use current_user.admin? with the before_action method (thus <code>before_action :current_user.admin?</code>), but I see this error.</p>
  
  <pre><code>**undefined method `admin?' for :current_user:Symbol**
  </code></pre>
  
  <p>I can't even use the method admin with the before_action method, and if you are wondering, yes, I'm logged.</p>
  
  <p>Now, what I can do is define a new method in the controller, such as admin_only thus.</p>
  
  <pre><code>  def admin_only
      if !current_user.admin then
        redirect_to :back, :alert =&gt; "Access denied."
      end
    end
  </code></pre>
  
  <p>And then use <code>before_action :admin_only</code> and it works well, but I think it breaks a little the logic of the controller to define a method such as admin_only. So... is there a way to filter administrators without having to define new methods in the controller?.</p>