trying to detect when the number of children an outage has changes

outage.rb

class Outage < ApplicationRecord
  has_many :children

  after_update :if_length_changed

  def if_length_changed
    o = Outage.find_by_id(self.id)
    if (o.children.any?(&:changed?) || o.children.collect(&:id).sort != o.children.pluck(&:id).sort)
      puts "\n\nlength was changed, count: #{o.children.count}\n\n"
    else
      puts "\n\nnotchanged, count: #{o.children.count}\n\n"
    end
  end
end