Active Admin Sorting Tables

active_admin_sorting_tables.rb

content do 
  order = case(params[:order])
  when 'user_email_desc'
    'email DESC'
  when 'user_email_asc'
    'email ASC'
  else
    nil
  end
      
      
  if(order.nil?) 
    users = User.all
  else 
    users = User.order(order)
  end
      
  panel 'Users' do 
    section :priority => 1 do 
      table_for users, {:sortable => true, :class => 'index_table'} do 
        column('Email', :sortable => :user_email) {|user| user.email}
      end
    end
  end
end