Factory method - when objects need information to get initalized

Question

Lets look on a simple example: assume that I have three classes implemeting IPersonRepository: SQLPersonRepository, WebPersonRepository, InMemoryPersonRepository. I also have PersonRepositoryFactory class which is simple Factory method pattern implementation - contains GetPersonRepository methods which have enum/string as parameter. How could I create Factory pattern (or in other words centralize my object creation) when SQLPersonRepository needs dependency for: SQLConnection or string to database path, WebPersonRepository needs some http settings object and InMemoryPersonRepository has no dependencies? I could pass it in Factory constructor or as method parameter but it'd be ugly, unclean and unmaintable especially if I had more IPersonRepository implementations.

Answer 1

I suggest to implement PersonRepositoryFactory as an abstract factory, with subclasses SQLPersonRepositoryFactory, WebPersonRepositoryFactory and InMemoryPersonRepositoryFactory. Those subclasses can have different constructor parameters (like SQLConnection, HttpSetting or no parameters). Once you have initialized those three factory objects, you can use them through an ordinary factory method for producing of many IPersonRepository objects, all with the same SQL connection or http settings.