Hi,
I have an AMP service that does cred-based auth with IBoxReceiver as the
interface (see mantissa). On login, the user gets a different API depending if
they're a staff member or not.
Additionally, I wrote a composing IResponderLocator. It takes a bunch of
responder locators and calls them in sequence to see if they can provide a
responder. The reason it exists is because I want to put behavior in their
separate, related modules, but @Command.responder is only supposed to work at
class definition time. Here's the implementation:
class ComposedLocator(object):
"""
A responder locator that consists of other locators.
"""
interface.implements(amp.IResponderLocator)
class __metaclass__(type):
def __new__(meta, name, bases, attrs):
"""
Makes sure every subclass gets its own set of locator classes.
"""
attrs["_locatorClasses"] = []
return type.__new__(meta, name, bases, attrs)
def __init__(self, *args, **kwargs):
self._locators = [l(*args, **kwargs) for l in self._locatorClasses]
def locateResponder(self, name):
"""
Locates a responder from all the component responders.
"""
for locator in self._locators:
responder = locator.locateResponder(name)
if responder is not None:
return responder
@classmethod
def component(cls, locatorClass):
"""
Registers a component locator.
"""
cls._locatorClasses.append(locatorClass)
return locatorClass
This has worked fine so far, but I've hit something so annoying to fix that I'm
wondering if I'm not doing something very stupid and overlooking the obvious.
I'm trying to implement a command called "Become" that allows a staff member to
work as if he was the user himself. The most obvious way (to me at least) to do
that to create the customer API (an IBoxReceiver/amp.BoxDispatcher subclass)
for that customer (that'd normally be the Realm's job -- but since we're
already logged in as an administrator, we don't go through Cred again), and
hook up the current connection with that box receiver. Yay, code reuse!
Except, no. Because of the composed locator detailed above, the responding
method has no reference to the box sender and box receiver. It's it's own
little standalone object, with barely any AMP-specific knowledge. Ordinarily
elegant, now annoying.
The only reason it ever worked before is because the default AMP implementation
basically just involves subclassing everything into one object (self is
self.boxReceiver is self.boxSender)
I don't see an obvious way to get a reference to the boxReceiver/boxSender from
the responder method using documented APIs. Does this just mean I have to leak
a reference to them all the way down? Am I doing something stupid?
cheers
lvh
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