File: LP6E/Chapter39/access_builtins_inline_direct.py
"Inline methods, skip validations"
traceMe = False
def trace(*args):
if traceMe: print('[' + ' '.join(map(str, args)) + ']')
def accessControl(failIf):
def onDecorator(aClass):
class onInstance:
def __init__(self, *args, **kargs):
self.__wrapped = aClass(*args, **kargs)
# Intercept and delegate built-in implicit access specifically
def __add__(self, other):
return self.__wrapped + other # Or getattr(), __getattr__()
def __str__(self):
return str(self.__wrapped) # Or self.__wrapped.__str__()
def __getitem__(self, index):
return self.__wrapped[index]
def __call__(self, *args, **kargs):
return self.__wrapped(*args, **kargs)
# Plus any others needed
# Intercept and delegate explicit attribute access generically
def __getattr__(self, attr):
trace('get:', attr)
if failIf(attr):
raise TypeError('private attribute fetch, ' + attr)
else:
return getattr(self.__wrapped, attr)
def __setattr__(self, attr, value):
trace('set:', attr, value)
if attr == '_onInstance__wrapped':
self.__dict__[attr] = value
elif failIf(attr):
raise TypeError('private attribute change, ' + attr)
else:
setattr(self.__wrapped, attr, value)
return onInstance
return onDecorator
def Private(*attributes):
return accessControl(failIf=(lambda attr: attr in attributes))
def Public(*attributes):
return accessControl(failIf=(lambda attr: attr not in attributes))