Object Oriented Design Choice

Question

I have a question on where to create, own and destroy data. The data itself are large tables of numbers, either randomly generated or read from the hard drive. This data is then subject to analysis, and depending on what exactly is analyzed, I have made a few wrapper like structures, which encapsulated the desired functionality. Since the wrapper can be switched in later stages, I decided against creating/reading the data inside the wrapper constructors, and just handle them in the "main" function. The wrappers then only see pointers of the data. First of, is this common/ a good idea, or should a wrapper always own its own copy of the data it wraps around? Well, next I made a "menu" class to better navigate through data creation/analysis choices etc, and the easiest would be to make the data part of the menu class. This doesn't feel good though, so where should I put it? Should it stay in the main class?

I hope this is understandable. If not, I can try to give a better outline of what is happening. Thank you for reading.

Answer 1

You could create a data class, and wrap other classes around it. An object of the data class probably should be global or defined inside main. OTher than that - your idea seems good. WIth a data class defined, you could also pass a pointer/reference to the menu, so you wouldn't have the problem with that. Note that a menu can also be a wrapper if you wish.

Answer 2

It's generally a better idea to keep the details of data in a specific wrapper class (I think you mean derived class?). Your wrapper classes should be derived from an interface or abstract type. You can construct wrapper-class factories in main(), and pass the factories around to constructors (constructors of the classes that are instantiated in main()). Later when the data-specific wrapper needs to be switched on or created, invoke the factory method. The factories can own the pointers, by which I mean they call new() and delete(). Try looking up SOLID principles and see how they guide you.