Commit 5864834f authored by Luke Plant's avatar Luke Plant
Browse files

Fixed a bug with method_decorator not preserving the attributes of the wrapped... 

Fixed a bug with method_decorator not preserving the attributes of the wrapped method, which is important for decorators like csrf_exempt

git-svn-id: http://code.djangoproject.com/svn/django/trunk@14311 bcc190cf-cafb-0310-a4f2-bffc1f526a37
parent df0bb3c4

django/utils/decorators.py

+15 −2
Original line number Diff line number Diff line
@@ -11,15 +11,28 @@ def method_decorator(decorator): 
    """

    Converts a function decorator into a method decorator

    """

    # 'func' is a function at the time it is passed to _dec, but will eventually

    # be a method of the class it is defined it.

    def _dec(func):

        def _wrapper(self, *args, **kwargs):

            @decorator

            def bound_func(*args2, **kwargs2):

                return func(self, *args2, **kwargs2)

            # bound_func has the signature that 'decorator' expects i.e.  no

            # 'self' argument, but it is a closure over self so it can call

            # 'func' correctly.

            return decorator(bound_func)(*args, **kwargs)

        return wraps(func)(_wrapper)

            return bound_func(*args, **kwargs)

        # In case 'decorator' adds attributes to the function it decorates, we

        # want to copy those. We don't have access to bound_func in this scope,

        # but we can cheat by using it on a dummy function.

        @decorator

        def dummy(*args, **kwargs):

            pass

        update_wrapper(_wrapper, dummy)

        # Need to preserve any existing attributes of 'func', including the name.

        update_wrapper(_wrapper, func)



        return _wrapper

    update_wrapper(_dec, decorator)

    # Change the name to aid debugging.

    _dec.__name__ = 'method_decorator(%s)' % decorator.__name__

tests/regressiontests/decorators/tests.py

+47 −1
Original line number Diff line number Diff line
@@ -126,14 +126,60 @@ def simple_dec(func): 
simple_dec_m = method_decorator(simple_dec)





# For testing method_decorator, two decorators that add an attribute to the function

def myattr_dec(func):

    def wrapper(*args, **kwargs):

        return func(*args, **kwargs)

    wrapper.myattr = True

    return wraps(func)(wrapper)



myattr_dec_m = method_decorator(myattr_dec)





def myattr2_dec(func):

    def wrapper(*args, **kwargs):

        return func(*args, **kwargs)

    wrapper.myattr2 = True

    return wraps(func)(wrapper)



myattr2_dec_m = method_decorator(myattr2_dec)





class MethodDecoratorTests(TestCase):

    """

    Tests for method_decorator

    """

    def test_method_decorator(self):

    def test_preserve_signature(self):

        class Test(object):

            @simple_dec_m

            def say(self, arg):

                return arg



        self.assertEqual("test:hello", Test().say("hello"))



    def test_preserve_attributes(self):

        # Sanity check myattr_dec and myattr2_dec

        @myattr_dec

        @myattr2_dec

        def func():

            pass



        self.assertEqual(getattr(func, 'myattr', False), True)

        self.assertEqual(getattr(func, 'myattr2', False), True)



        # Now check method_decorator

        class Test(object):

            @myattr_dec_m

            @myattr2_dec_m

            def method(self):

                "A method"

                pass



        self.assertEqual(getattr(Test().method, 'myattr', False), True)

        self.assertEqual(getattr(Test().method, 'myattr2', False), True)



        self.assertEqual(getattr(Test.method, 'myattr', False), True)

        self.assertEqual(getattr(Test.method, 'myattr2', False), True)



        self.assertEqual(Test.method.__doc__, 'A method')

        self.assertEqual(Test.method.im_func.__name__, 'method')