Kuidas rakendatakse sõltuvuste pööramise põhimõtet Clean Architecture'is, et jagada vastutust kihtide vahel?

In clean architecture, the Dependency Inversion Principle is applied to separate responsibilities between layers as follows:

• High-level modules (e.g., business logic) do not depend on low-level modules (e.g., data access implementations or UI), but both depend on abstractions (interfaces).

• Abstractions are defined in higher layers (e.g., in the domain layer), and the implementations of these interfaces are located in lower layers (e.g., in the infrastructure).

• This allows business logic to be independent of implementation details, facilitating testing, maintenance, and extension.

Example: a repository interface is defined in the domain layer:

interface UserRepository {
    fun getUser(id: String): User
}

This interface is implemented in the data layer:

class UserRepositoryImpl : UserRepository {
    override fun getUser(id: String): User {
        // implementation of data access
    }
}

Business logic depends only on the UserRepository interface, and the concrete implementation is injected via constructor or DI container. This way, layers are connected through abstractions, not directly.