The project architecture is based on MVVM + Coordinators, where logic is decomposed into four main parts: View, Modal View, ViewModel and Coordinator.
ViewModel is a class which contains business logic except for navigation. It is a subclass of ObservableObject, and the interaction between the ViewModel and View is done by @published properties of the ViewModel. The ViewModel is signed by ViewModelType Protocol which contains inputs, outputs and bindings.
For navigation, the ViewModel interacts with the Coordinator using Combine, with two Structs and Properties: Routing and Output. Both Structs conform to RoutingProtocol and OutputProtocol, and contain PassthroughSubjects of any value types.
The Coordinator should subclass Coordinator, and has a generic type ResultType which indicates the result the Coordinator returns after it is dismissed. It has a unique identifier and a dictionary of child Coordinators. To present a Coordinator on top of another, the coordinateTo(coordinator:) method should be called which stores the Coordinator in childCoordinators and runs the start() method.
Services are Structs with methods for interacting with external API. Every method returns AnyPublisher which emits a value (or error) when the request is finished.
Routers are basic Classes which contain static methods for Modal Presentation - present() and dismiss(), NavigationController Property and custom Push and Pop methods. The Router should be used to handle popping action, passing onNavigateBack closure and doing actions when the ViewController is popped using gesture. To present Modals, present(modalTransitionStyle:modalPresentationStyle:animated:) should be used.