메서드 동적으로 생성하기

define_method 사용하기

class Person
  define_method(:greet) { puts 'Hello!' }
end

p = Person.new
p.greet

매개변수와 함께 define_method 사용하기

class Person
  define_method(:greet) { |name| puts "Hello, #{name}!" }
end

p = Person.new
p.greet('Alice')

method_missing 사용하기

class Person
  def method_missing(name, *args)
    puts "Method '#{name}' is missing!"
  end
end

p = Person.new
p.unknown_method

method_missing 동적으로 처리하기

class DynamicPerson
  def method_missing(name, *args)
    if name.to_s.start_with?('say_')
      puts "You asked me to say: #{name.to_s.split('_')[1..-1].join(' ')}"
    else
      super
    end
  end
end

p = DynamicPerson.new
p.say_hello_world

respond_to_missing? 재정의하기

class DynamicPerson
  def method_missing(name, *args)
    if name.to_s.start_with?('say_')
      puts "Saying: #{name.to_s.split('_')[1..-1].join(' ')}"
    else
      super
    end
  end
  
  def respond_to_missing?(name, include_private = false)
    name.to_s.start_with?('say_') || super
  end
end

p = DynamicPerson.new
puts p.respond_to?(:say_hello)

동적 조회자와 설정자에 method_missing 사용하기

class DynamicPerson
  def initialize
    @data = {}
  end
  
  def method_missing(name, *args)
    attribute = name.to_s.sub(/=$/, '')
    if name.to_s.end_with?('=')
      @data[attribute] = args.first
    else
      @data[attribute]
    end
  end
end

p = DynamicPerson.new
p.name = 'Alice'
puts p.name

method_missing의 보안 위험

동적 메서드 복습