Add method when set variable using monkey patching

set_variable_callback.rb

class Module
  def fields_callbacks(fields)
    fields.each do |field, value|
      class_eval do
        alias :"old_#{field}=" :"#{field}="
        define_method("#{field}=") do |v|
          value.each { |method| send(method) }
          send("old_#{field}=", v)
        end
      end
    end 
  end
end
  
class Human
  attr_accessor :name
  fields_callbacks :name => [:tadaaam]
  
  private
  def tadaaam
    puts "TADAAAAM"
  end
end

dude = Human.new
dude.name = "Jack" # => "TADAAAAM"