module Facade

Constants

FACADE_VERSION: The version of the facade library

Public Instance Methods

facade(klass, *methods) click to toggle source

The facade method will forward a singleton method as an instance method of the extending class. If no arguments are provided, then all singleton methods of the class or module become instance methods.

Existing instance methods are NOT overridden, but are instead ignored.

Example:

require 'facade'

class MyString < String
   extend Facade
   facade File, :dirname, :basename
end

s = MyString.new('/home/djberge')
s.basename # => 'djberge'
s.dirname  # => '/home'

# File lib/facade.rb, line 24
def facade(klass, *methods)
  methods = methods.flatten

  if methods.empty? # Default to all methods
    if klass.kind_of?(Class)
      methods = klass.methods(false)
    else
      methods = klass.public_instance_methods(false)
    end
  end

  # Convert all strings to symbols to stay sane between 1.8.x and 1.9.x
  methods = methods.map{ |m| m.to_sym }
  methods -= self.instance_methods.map{ |m| m.to_sym } # No clobber

  methods.each do |methname|
    define_method(methname){
      if klass.kind_of?(Class)
        meth = klass.method(methname)
      else
        meth = Object.new.extend(klass).method(methname)
      end

      if meth.arity.zero? # Zero or one argument
        meth.call
      else
        meth.call(self)
      end
    }
  end
end