I am using a factory pattern to get objects that shouldn't be instantiated other than the factory class. These objects are of type ViolationType, which represent violations on a set of rule. Here is the summary of the factory and the available violation types:
class ViolationFactory: def __init__(self): raise ValueError('%s cannot be instantiated' % self.__class__.__name__) class ViolationType: def __init__(self, name): self.name = name _violations = ( ViolationType('RULE_X'), ViolationType('RULE_Y'), # the rest of the types... ) _violations_dict = {v.name: v for v in _violations} @staticmethod def get(violation_name): if violation_name not in ViolationFactory._violations_dict: raise ValueError('Invalid ViolationType') return ViolationFactory._violations_dict[violation_name] A ViolationType is primarily used to instantiate a Violation:
violation = Violation(ViolationFactory.get('RULE_X'), **kwargs) The problem with this is that if I misspell the string passed to the get() factory method I won't know there is an error until that particular piece of code is ran. So if I try doing ViolationFactory.get('RULE_Z') and such type doesn't exist, it should throw an error when running the program
I think the current design simply doesn't allow such behavior, so: how could I redesign it so that I get a load time error rather than a run time one?
