Service objects, noun-first

service_objects_noun_first.rb

# Illustrate the usage of service objects named in the noun-first form.

# a test user
user = User.where(name: 'Oleg').first

UserListSubscription.subscribe(oleg, list)
# => "Oleg was added to the mailing list."

UserListSubscription.unsubscribe(oleg, list)
# => "Oleg was removed from the mailing list."

GoodbyeEmailDelivery.send(oleg)
# => "Sent a goodbye email to Oleg."

UserCommentRemoval.remove(oleg)
# => "Removed comments by Oleg."

InactiveUserArchival.archive([oleg])
# => "Oleg was removed from the 10x10 list."
# => "Sent a goodbye email to Oleg."
# => "Removed comments by Oleg.

goodbye_email_delivery.rb

# app/services/goodbye_email_delivery.rb
class GoodbyeEmailDelivery
  def self.send(user)
    # Notifier.goodbye(user).deliver
    puts "Sent a goodbye email to #{user.name}."
  end
end

inactive_user_archival.rb

# app/services/inactive_user_archival.rb
class InactiveUserArchival
  def self.archive(users)
    users.each do |user|
      UserListSubscription.unsubscribe(user)
      GoodbyeEmailDelivery.send(user)
      UserCommentRemoval.remove(user)
    end
  end
end

user_comment_removal.rb

# app/services/user_comment_removal.rb
class UserCommentRemoval
  def self.remove(user)
    # user.comments.destroy_all
    puts "Removed comments by #{user.name}."
  end
end

user_list_subscription.rb

# app/services/user_list_subscription.rb
class UserListSubscription
  def self.subscribe(user, list = MailingList.new)
    # list.add!(user.email)
    puts "#{user.name} was added to the #{list.name} list."
  end

  def self.unsubscribe(user, list = MailingList.new)
    # list.remove!(user.email)
    puts "#{user.name} was removed from the #{list.name} list."
  end
end