module Extensible

Use Extensible on your custom extensions in order to get a set of advantages over traditional extensions that override the Module#extended method directly. When extending Extensible you will be able to define your initialization code (similar to using Module#extended) via the when_extended method.

module MyExtension
  extend Extensible
  when_extended {|m| puts "#{self} has extended #{m}." }
end

class MyClass
  extend MyExtension
end  #=> MyExtension has extended MyClass.

Extensible is, itself, extensible. This means that you will be able to extend it further or bundle it together with other extensible modules by including it in your module.

module MyExtensibleExtension
  include Extensible

  def custom_when_extended(&block)
    puts "Defining initialization code..."
    when_extended &block
  end
end

module MyExtension
  extend MyExtensibleExtension
  custom_when_extended {|m| puts "#{self} has extended #{m}." }
end  #=> Defining initialization code...

class MyClass
  extend MyExtension
end  #=> MyExtension has extended MyClass.

Constants

ExtensionKernel: A custom ExtensionKernelTemplate clone that is extended by Extensible to make it, well, extensible.
VERSION: Current version of Extensible.

Private Instance Methods

when_extended() {|extended_module| ... } → module click to toggle source

The when_extended method accepts a code block that will be executed every time this module is extended in a manner similar to Module#extended. The code block will be passed an extended_module parameter containing the module that is being extended. There is no need to make explicit calls to super as those will be made internally by Extensible.

Returns self (this module).

Calls superclass method

# File lib/extensible.rb, line 53
def when_extended
  raise LocalJumpError, "no block given".freeze unless block_given?

  self::ExtensionKernel.module_eval do
    define_method :extended do |submodule|
      super submodule
      yield submodule
      self
    end

    private :extended
  end

  self
end