Abstract Factory Pattern

Abstract factory – provides an interface for creating the corresponding objects, without specifying specific classes.

I really like the alternative name for this pattern – Kit

It is very similar to the Factory Method, however, Abstract Factories should describe the relationship between the created objects, otherwise it is already just the antipattern God Object, creating unsystematically everything.

Imagine the development of an AR framework for glasses, we display on the screen arrows for indoor navigation, store icons, interesting places, windows and buttons with information about any place where the user is now located.

At the same time, we need the ability to customize the appearance and behavior of the controls of the AR environment. That’s it for this case, you need to use the Set pattern.

We’ll write the interface of Abstract Factory and Products – parent protocols, elements of the AR environment:

 
protocol ARFactory {
    func arrow() -> ARArrow
    func icon() -> ARIcon
    func button() -> ARButton
    func window() -> ARWindow
}

protocol ARArrow {
    var image: { get }
    func handleSelection()
}

protocol ARIcon {
    var image: { get }
    var title: String
}

protocol ARButton {
    var title: String
    func handleSelection()
}

protocol ARWindow {
    var title: String
    var draw(canvas: Canvas)
}
 

Now the kit developers will need to implement the Concrete Factory on the basis of the Abstract Factory interface, and all the elements will have to be implemented together, the rest of the application will be able to work with the factory without changing its code.

References

https://refactoring.guru/design-patterns/abstract-factory
https://www.amazon.com/Design-Patterns-Elements-Reusable-Object-Oriented/dp/0201633612

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