ForecastApp

ForecastApp iOS App is built using Clean Architecture and MVVM

Domain Layer = Entities + Use Cases + Gateways Interfaces
Data Repositories Layer = Repositories Implementations + API (Network) + Persistence DB
Presentation Layer (MVVM) = ViewModels + Views

Note: Domain Layer should not include anything from other layers(e.g Presentation — UIKit or SwiftUI or Data Layer — Mapping Codable)

UseCase / Interactor - contains the application / business logic for a specific use case in your application
- It is referenced by the Presenter. The Presenter can reference multiple UseCases since it's common to have multiple use cases on the same screen
- It manipulates Entities and communicates with Gateways to retrieve / persist the entities
- The Gateway protocols should be defined in the Application Logic layers and implemented by the Gateways & Framework Logic
- The separation described above ensures that the Application Logic depends on abstractions and not on actual frameworks / implementations
- It should be covered by Unit Tests
Entity - plain Swift classes / structs
- Models objects used by your application Main, Item, etc.

Gateway - contains actual implementation of the protocols defined in the Application Logic layer
- We can implement for instance a LocalPersistenceGateway protocol using CoreData or Realm
- We can implement for instance an ApiGateway protocol using URLSession or Alamofire
- We can implement for instance a UserSettings protocol using UserDefaults
- It should be covered by Unit Tests
Persistence / API Entities - contains framework specific representations
- For instance we could have a CoreDataOrder that is a NSManagedObject subclass
- The CoreDataOrder would not be passed to the Application Logic layer but rather the Gateways & Framework Logic layer would have to "transform" it to an Order entity defined in the Application Logic layer
Framework specific APIs - contains implementations of iOS specific APIs such as sensors / bluetooth / camera