Module: Facade

Defined in:
lib/facade.rb

Constant Summary collapse

FACADE_VERSION =

The version of the facade library

'1.0.7'

Instance Method Summary collapse

Instance Method Details

#facade(klass, *methods) ⇒ Object

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'



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# 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