>Care to explain what's wrong with singletons? As others have mentioned, true singletons preclude unit testing IMO. A true unit test relies on the fact that one test does not affect another. If one test creates any global states, including a singleton, then it necessarily alters the starting state for the next test.
I have no problem with something _acting_ like a singleton and ensuring that, within a given context, there is only one copy. I just think that enforcement should happen via something like dependency injection wherein you can choose whether it is truly 'globalish', contextual or that you choose to create a new one every time (which is the case when you are testing). Hope that makes some sense. Honestly, there is nothing wrong with any pattern, it is simply that patterns have usefulness within certain confines. A singleton is a great way to approach certain applications but begins to get in your way when you have multiple modules (especially if you want to unload them), testing or areas of your application that need different contexts. This is not the case for many, many applications and hence like any other tool, I say use them but understand when not to. Mike
