Why clean architecture maintains codebases in iOS Swift - Test Your Understanding

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a protocol for the use case layer.

iOS Swift

protocol [1] {
    func execute()
}

Drag options to blanks, or click blank then click option'

AService

BUseCase

CModel

DViewController

Attempts:

3 left

💡 Hint

Common Mistakes

Using ViewController as protocol name mixes UI with business logic.

Using Model or Service does not clearly represent the use case layer.

The use case layer is defined by a protocol named UseCase to separate business logic from UI.

2fill in blank

medium

Complete the code to inject the dependency in the initializer.

iOS Swift

class Presenter {
    let useCase: [1]

    init(useCase: [1]) {
        self.useCase = useCase
    }
}

Drag options to blanks, or click blank then click option'

AUseCase

BUIViewController

CRepository

DService

Attempts:

3 left

💡 Hint

Common Mistakes

Using UIViewController mixes UI with business logic.

Using Repository or Service without protocol abstraction reduces flexibility.

Dependency injection uses the UseCase protocol to keep the presenter independent of concrete implementations.

3fill in blank

hard

Fix the error in the code by choosing the correct layer to handle data fetching.

iOS Swift

class [1] {
    func fetchData() {
        // fetch data from network or database
    }
}

Drag options to blanks, or click blank then click option'

ARepository

BViewController

CPresenter

DUseCase

Attempts:

3 left

💡 Hint

Common Mistakes

Putting fetchData in ViewController mixes UI with data logic.

Presenter or UseCase should not directly fetch data.

The Repository layer handles data fetching to separate data sources from business logic and UI.

4fill in blank

hard

Fill both blanks to complete the clean architecture layers interaction.

iOS Swift

class [1] {
    let repository: [2]

    func execute() {
        repository.fetchData()
    }
}

Drag options to blanks, or click blank then click option'

AUseCase

BViewController

CRepository

DPresenter

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing Presenter or ViewController with UseCase.

Assigning ViewController as repository type.

The UseCase calls the Repository to get data, keeping layers separate and maintainable.

5fill in blank

hard

Fill all three blanks to complete the flow from UI to data layer.

iOS Swift

class [1] {
    let useCase: [2]

    func present() {
        useCase.execute()
    }
}

class [3] {
    func fetchData() {}
}

Drag options to blanks, or click blank then click option'

APresenter

BUseCase

CRepository

DViewController

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing ViewController with Presenter or UseCase.

Assigning ViewController as data fetcher.

The Presenter calls the UseCase, which uses the Repository to fetch data, following clean architecture principles.