Page objects example

1-welcome_page.rb

class WelcomePage
  attr_reader :greeting, :recent_activity, :support_email

  def self.from_user(user)
    new \
      greeting: "Good #{user.time_of_day}, #{user.name}",
      recent_activity: ActivityItem.from_user(user),
      support_email: Rails.configuration.app.support_email
  end

  def initialize(greeting:, recent_activity:, support_email:)
    @greeting = greeting
    @recent_activity = recent_activity
    @support_email = support_email
  end
end

2-controller.rb

def show
  @page = WelcomePage.from_user(current_user)
end

3-view.html.erb

<h2><%= @page.greeting %></h2>

<ul>
  <%= @page.recent_activity.each do |item| %>
    <li>
      <strong><%= item.name %></strong>: <%= item.description %>
    </li>
  <% end %>
</ul>

<p>Get help: <%= mail_to @page.support_email %></p>

4-welcome_page_portrayal.rb

# This is an alternative example of welcome_page.rb using https://github.com/maxim/portrayal
# Assuming that ApplicationStruct has `extend Portrayal`.
# In this one I also do an example definition of ActivityItem class.

class WelcomePage < ApplicationStruct
  def self.from_user(user)
    new \
      greeting: "Good #{user.time_of_day}, #{user.name}",
      recent_activity: ActivityItem.from_user(user),
      support_email: Rails.configuration.app.support_email
  end

  keyword :greeting
  keyword :support_email
  keyword :recent_activity, defines: 'ActivityItem' do
    def self.from_user(user)
      user.events.last(3).map { |event|
        new(name: event.name, description: event.description)
      }
    end

    keyword :name
    keyword :description
  end
end