File: delegate.rb

 Delegation class that delegates even methods defined in super class,

which can not be covered with normal method_missing hack.

 Delegator is the abstract delegation class. Need to redefine

`getobj’ method in the subclass. SimpleDelegator is the concrete subclass for simple delegation.

Usage:

  foo = Object.new
  foo2 = SimpleDelegator.new(foo)
  foo.hash == foo2.hash # => false

  Foo = DelegateClass(Array)

 class ExtArray<DelegateClass(Array)
   ...
 end

Methods

DelegateClass __getobj__ __setobj__ clone dup method_missing new

Constants

Delegater	=	Delegator		backward compatibility ^_^;;;
SimpleDelegater	=	SimpleDelegator

Public Class methods

new(obj)

[Source]

# File delegate.rb, line 101
    def initialize(obj)
      @_dc_obj = obj
    end

Public Instance methods

DelegateClass(superclass)

[Source]

# File delegate.rb, line 95
def DelegateClass(superclass)
  klass = Class.new
  methods = superclass.public_instance_methods(true)
  methods -= ::Kernel.public_instance_methods(false)
  methods |= ["to_s","to_a","inspect","==","=~","==="]
  klass.module_eval {
    def initialize(obj)
      @_dc_obj = obj
    end
    def method_missing(m, *args)
      unless @_dc_obj.respond_to?(m)
        super(m, *args)
      end
      @_dc_obj.__send__(m, *args)
    end
    def __getobj__
      @_dc_obj
    end
    def __setobj__(obj)
      @_dc_obj = obj
    end
    def clone
      super
      __setobj__(__getobj__.clone)
    end
    def dup
      super
      __setobj__(__getobj__.dup)
    end
  }
  for method in methods
    begin
      klass.module_eval "def \#{method}(*args, &block)\nbegin\n@_dc_obj.__send__(:\#{method}, *args, &block)\nrescue\n$@[0,2] = nil\nraise\nend\nend\n"
    rescue SyntaxError
      raise NameError, "invalid identifier %s" % method, caller(3)
    end
  end
  return klass
end

__getobj__()

[Source]

# File delegate.rb, line 110
    def __getobj__
      @_dc_obj
    end

__setobj__(obj)

[Source]

# File delegate.rb, line 113
    def __setobj__(obj)
      @_dc_obj = obj
    end

clone()

[Source]

# File delegate.rb, line 116
    def clone
      super
      __setobj__(__getobj__.clone)
    end

dup()

[Source]

# File delegate.rb, line 120
    def dup
      super
      __setobj__(__getobj__.dup)
    end

method_missing(m, *args)

[Source]

# File delegate.rb, line 104
    def method_missing(m, *args)
      unless @_dc_obj.respond_to?(m)
        super(m, *args)
      end
      @_dc_obj.__send__(m, *args)
    end