GoF design pattern - Decorator

decorator.py

#!/usr/bin/env python
# -*- coding: utf-8 -*-

"""http://stackoverflow.com/questions/3118929/implementing-the-decorator-pattern-in-python"""

class foo_decorator(object):
	def __init__(self, decoratee):
		self._decoratee = decoratee

	def f1(self):
		print("decorated f1")
		self._decoratee.f1()

	def __getattr__(self, name):
		return getattr(self._decoratee, name)


class undecorated_foo(object):
	def f1(self):
		print("original f1")

	def f2(self):
		print("original f2")


@foo_decorator
class decorated_foo(object):
	def f1(self):
		print("original f1")

	def f2(self):
		print("original f2")


def main():
	u = undecorated_foo()
	v = foo_decorator(u)
	# The @foo_decorator syntax is just shorthand for calling
	# foo_decorator on the decorated object right ofter its
	# decoration.

	v.f1()
	v.f2()


if __name__ == '__main__':
	main()