Facade pattern

index.html.erb

<% if facade.logged_in? %>
<ul>
  <% facade.active_users.each do |user| %>
    <li><%= user.name %></li>
  <% end %>
</ul>
<% else %>
  <p>You are not logged in!</p>
<% end %>

user_listing_facade.rb

class UserListingFacade
  attr_reader :user
  
  def initialize(user)
    @user = user
  end
  
  def active_users
    @active_users ||= User.published.ordered 
  end
  
  def logged_in?
    !user.nil?  
  end
end

users_controller.rb

class UsersController < ApplicationController
  def index
    @facade = UserListingFacade.new(current_user)
  end
  
  private
  
  def facade
    @facade ||= ApplicationFacade.new
  end
  helper_method :facade
end