title: Active Admin scopes for each instance of a related model
body: <p>I have an issue with a dynamic active admin scope.  I am attempting to create a scope for each "manager" of a "project" in my app.  However, the scopes don't seem to update when a new manager is created (or assigned to a project) but they DO update if I restart the server.  So the code "works" per se but obviously not in the way I would like it to.  I'm a ruby/rails noob so I am not sure if I need to do something to "refresh" the scope in some way.</p>
  
  <p>As an FYI, I am using Rails 3.2 on Heroku Cedar with ActiveAdmin</p>
  
  <p>Here is the code in question (that works but only brings in new managers after the server is restarted):</p>
  
  <hr>
  
  <pre><code>Manager.find_each do |m|
    scope m.first_name do |projects|
      projects.where(:manager_id =&gt; m.id)
    end
  end
  </code></pre>
  
  <p>And the entire Active Admin Project model:</p>
  
  <pre><code>ActiveAdmin.register Project do
   menu :priority =&gt; 1
   index do
    column :name
    column :company_name
    column :status
    column :projection do |project|
     number_to_currency project.projection
    end
    column :updated_at
    default_actions
   end
  
   scope :all
   scope :working, :default =&gt; true do |projects|
    projects.where(:status =&gt; 'working')
   end
  
   Manager.find_each do |m|
    scope m.first_name do |projects|
      projects.where(:manager_id =&gt; m.id)
    end
   end
  end
  </code></pre>