service_objects_bp_4.rb

class CommentCreator
  #...

  def perform
    ThreadParticipantsNotifier.new(@comment).notify

    if comment.previous_comment?
      in_reply_to_user = comment.previous_comment.author
      ReplyMailer.notification(in_reply_to_user, comment).deliver
    end

    Kissmetrics.record(comment.author, 'Added Comment')
  end
end

class ThreadParticipantsNotifier
  def initialize(comment)
    @comment = comment
  end

  def notify
    participants.each { |partipiant| notify_participant(participant) }
  end

  private

  def notify_participant(participant)
    CommentThreadMailer.activity_notification(comment_thread, comment, participant)
  end

  def participants
    comment_thread.participants
  end

  def comment_thread
    @comment.comment_thread
  end
end