Ruby Fundamental - Hooks (ganchos) de inclusão e extensão de módulos

modulos_hooks_01.rb

module SomeInstanceMethods
  def self.included(base)
    puts "Module #{self} has been included by #{base}."
  end

  def some_instance_method
    puts "Some instance method..."
  end
end

modulos_hooks_02.rb

class SomeClass1
  include SomeInstanceMethods
end
# => Module SomeInstanceMethods has been included by SomeClass1. 

some_class = SomeClass1.new
some_class.some_instance_method # => Some instance method...

modulos_hooks_03.rb

module SomeClassMethods
  def self.extended(base)
    puts "Module #{self} has been extended by #{base}."
  end

  def some_class_method
    puts "Some class method..."
  end
end

modulos_hooks_04.rb

class SomeClass2
  extend SomeClassMethods
end
# => Module SomeClassMethods has been extended by SomeClass2.

SomeClass2.some_class_method # => Some class method...

modulos_hooks_05.rb

class SomeClass3
  include SomeInstanceMethods
  extend SomeClassMethods
end
# => Module SomeInstanceMethods has been included by SomeClass3.
# => Module SomeClassMethods has been extended by SomeClass3.

modulos_hooks_06.rb

module SomeIncludedModule
  def self.included(base)
    base.send(:include, InstanceMethods)
    base.extend(ClassMethods)

    puts "Module #{self} has been included by #{base}."
  end

  module InstanceMethods
    def some_instance_method
      puts "Some instance method..."
    end
  end

  module ClassMethods
    def some_class_method
      puts "Some class method..."
    end
  end
end

modulos_hooks_07.rb

class SomeClass4
  include SomeIncludedModule
end
# => Module SomeIncludedModule has been included by SomeClass4.

SomeClass4.new.some_instance_method # => Some instance method...
SomeClass4.some_class_method # => Some class method...

modulos_hooks_08.rb

module SomeExtendedModule
  def self.extended(base)
    base.send(:include, InstanceMethods)
    base.extend(ClassMethods)

    puts "Module #{self} has been extended by #{base}."
  end

  module InstanceMethods
    def some_instance_method
      puts "Some instance method..."
    end
  end

  module ClassMethods
    def some_class_method
      puts "Some class method..."
    end
  end
end

modulos_hooks_09.rb

class SomeClass5
  extend SomeExtendedModule
end
# => Module SomeExtendedModule has been extended by SomeClass5.

SomeClass5.new.some_instance_method # => Some instance method...
SomeClass5.some_class_method # => Some class method...

modulos_hooks_10.rb

module SomeCoolModule
  def self.included(base)
    mix_modules!(base)
  end

  def self.extended(base)
    mix_modules!(base)
  end

  private

  def self.mix_modules!(base)
    base.send(:include, InstanceMethods)
    base.extend(ClassMethods)
  end

  module InstanceMethods
    def some_instance_method
      puts "Some instance method..."
    end
  end

  module ClassMethods
    def some_class_method
      puts "Some class method..."
    end
  end
end

class SomeClass6
  include SomeCoolModule
end

class SomeClass7
  extend SomeCoolModule
end

SomeClass6.new.some_instance_method # => Some instance method...
SomeClass6.some_class_method # => Some class method...

SomeClass7.new.some_instance_method # => Some instance method...
SomeClass7.some_class_method # => Some class method...