Top Level Namespace

Defined Under Namespace

Classes: Delegator, ExtArray, SimpleDelegator

Constant Summary

Delegater =

:stopdoc: backward compatibility ^_^;;;

Delegator

SimpleDelegater =

SimpleDelegator

Instance Method Summary

• #DelegateClass(superclass) ⇒ Object

  The primary interface to this library.

Instance Method Details

#DelegateClass(superclass) ⇒ Object

The primary interface to this library. Use to setup delegation when defining your class.

class MyClass < DelegateClass( ClassToDelegateTo )    # Step 1
def initiaize
  super(obj_of_ClassToDelegateTo)                   # Step 2
end
end

# File 'lib/delegate.rb', line 257

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)  # :nodoc:
      @_dc_obj = obj
    end
    def method_missing(m, *args)  # :nodoc:
      unless @_dc_obj.respond_to?(m)
        super(m, *args)
      end
      @_dc_obj.__send__(m, *args)
    end
    def respond_to?(m)  # :nodoc:
      return true if super
      return @_dc_obj.respond_to?(m)
    end
    def __getobj__  # :nodoc:
      @_dc_obj
    end
    def __setobj__(obj)  # :nodoc:
      raise ArgumentError, "cannot delegate to self" if self.equal?(obj)
      @_dc_obj = obj
    end
    def clone  # :nodoc:
      super
      __setobj__(__getobj__.clone)
    end
    def dup  # :nodoc:
      super
      __setobj__(__getobj__.dup)
    end
  }
  for method in methods
    begin
      klass.module_eval <<-EOS
        def #{method}(*args, &block)
	  begin
	    @_dc_obj.__send__(:#{method}, *args, &block)
	  rescue
	    $@[0,2] = nil
	    raise
	  end
	end
      EOS
    rescue SyntaxError
      raise NameError, "invalid identifier %s" % method, caller(3)
    end
  end
  return klass
end