mod = getattr(mod, comp)
return mod
+class ManagerWrapper:
+ """
+ This class acts as a wrapper around an SFA interface manager module, but
+ can be used with any python module. The purpose of this class is raise a
+ SfaNotImplemented exception if the a someone attepmts to use an attribute
+ (could be a callable) thats not available in the library by checking the
+ library using hasattr. This helps to communicate better errors messages
+ to the users and developers in the event that a specifiec operation
+ is not implemented by a libarary and will generally be more helpful than
+ the standard AttributeError
+ """
+ def __init__(self, manager, interface):
+ self.manager = manager
+ self.interface = interface
+
+ def __getattr__(self, method):
+
+ if not hasattr(self.manager, method):
+ raise SfaNotImplemented(method, self.interface)
+ return getattr(self.manager, method)
+
class BaseAPI:
cache = None
manager_module = manager_base + ".component_manager_%s" % mgr_type
else:
raise SfaAPIError("No manager for interface: %s" % self.interface)
- manager = __import__(manager_module, fromlist=[manager_base])
-
+ manager = __import__(manager_module, fromlist=[manager_base])
+ # this isnt necessary but will hlep to produce better error messages
+ # if someone tries to access an operation this manager doesn't implement
+ manager = ManagerWrapper(manager, self.interface)
+
return manager
def callable(self, method):