Cocoa Design Patterns: Classes, Singletons and Managers - When to use?
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Now that I have a fairly good grasps of objective-c I'm moving on up to the next level of understanding how to write code more effectively. I'm reading Buck and Yacktman's Cocoa Design Patterns which is quite informative. From that I've looked back on a couple of apps I've built and am wondering if classes I've made should really be singletons or managers. 

For example, I have a class that makes SOAP calls and one that parses XML. Based on B&Y I am thinking that both these classes should be singletons. 

If I am understanding B&Y correctly I should use this methodology:

Class: If I need to instantiate the object multiple times, a Player object in a game that supports multiple players perhaps.

Singlton: The object needs to be instantiated only once. I'll use my SOAP class as an example. It just passes calls to the URL and takes the returned data and sends it on to whatever called it. 

Manager: If you had a game that supported multiple players you could have a player manager that kept track of their properties, like location, score, health, etc.

Is that accurate?

