Hi!

First of all, a very awesome project and article on clean architecture with SwiftUI.

I have a question though.

You say Instead, they forward the result to the AppState or to a Binding. The latter is used when the result of work (the data) is used locally by one View and does not belong to the AppState.

For the first case, I can subscribe to any data change in Store by using something like routingUpdate and then .onReceive(routingUpdate) { _ in }. But I am a bit struggling with the latter case - I pass a binding to an Interactor when the data is only applicable to one view. I modify the binding in that Interactor, my views react to the change, but I also want to subscribe that change in the view and do some additional actions/interactions. How would I achieve that?

Hi there !

At first thank you for providing this repository and your related blog posts. I enjoyed reading them and they helped me a lot.

But I have a question about reacting to @State changes in Views in this architecture.

For example I have the following case in my application:

I have a view which displays a list of tasks for a specific date interval. It has your dependency injection container injected:

@Environment(\.injected) private var injected: DIContainer
@State private var dateInterval: DateInterval = DateInterval(start: Date().startOfWeek ?? Date(), end: Date().endOfWeek ?? Date())

Initially the data is fetched with a method that looks like this:

func fetch() {
    injected.interactors.myInteractor
        .fetchData(range: self.dateInterval)
        .store(in: cancelBag)
}

The view has a child which accepts a binding to the dateInterval and is able to change it:

 WeeksTaskGraph(dateInterval: self.$dateInterval, tasks: tasks)

Now I need to refetch data when the binding changes. So basically I would need to run the fetch method again when the dateInterval changes. I tried to create an ObservableObject ViewModel class for the view, for encapsulating this kind of functionality. It looks roughly like this:

class DateIntervalModel: ObservableObject {
    
    private let cancelBag = CancelBag()
    
    @Environment(\.injected) private var injected: DIContainer
    
    @Published var dateInterval: DateInterval = DateInterval(start: Date().startOfWeek ?? Date(), end: Date().endOfWeek ?? Date()) {
        didSet {
            print("Date interval changed")
             injected.interactors.myInteractor.fetchData(range: self.dateInterval)
                .store(in: cancelBag)
        }
    }
}

But as seen this class would then need access to the @EnvironmentObject which I could not find a solution how to achieve that - since it is not part of the view hierarchy.

Do you maybe have an approach or a suggestion how this can be achieved with the clean architecture ?

Any help is appreciated ! If this is the wrong place for asking this kind of questions feel free to close the issue or tell me so.

Would you consider adding an example of full-screen view transition animations based on Routing to this project? Something where both - the new view and the previous view - would have different transition animations. Say, previous view scales down and the new view slides in.

This is by far the best SwiftUI example I have found to date (and I keep up on this stuff!)

I was wondering if you have any plans of adding some user actions, I am particularly curious how you would handling deletion of an item from a list. Again thank you so much for this resource.

Awesome template for clean architecture!

I've the below combine pipeline which is the opposite of way you're handling data in this template; In most real world scenarios;

• data is first fetched from the web
• then stored in the db
• if fetching from web fails
• load from db

func refreshCards(id: String) -> AnyPublisher<Void, Error> {
    var cards: [Card] = []
    return gateway
    .listCards(customerID: id)
    .map {
        response in
        response.cards.forEach {
            cards.append(Card(protoObject: $0)!)
        }
        return cards
    }

    .catch {
        err in
        // must return a Publisher
        repository.cards()
    }

    .flatMap {
        [repository] in
        repository.store(cards: $0) // Cannot convert value of type 'LazyList<Card>' to expected argument type '[Card]'
    }

    .eraseToAnyPublisher()
}

repository.store(cards: ) accepts an array of cards - [Card] - how can I unpack LazyList and turn it into an array?

I am pretty new to iOS development and I don't have background of Javascript and UIKit. I am learning SwiftUI directly.

Why did you used @Enviroment and not @EnviromentObject in your project? Can you please add comments in your code so it will more useful for beginners like me.

Thanks for creating this project and post related to it. It was very helpful and appreciated :)

/UnitTests/Mocks/MockedInteractors.swift:38:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'loadCountryDetails(_:)' (identifier_name)

/UnitTests/Mocks/MockedInteractors.swift:63:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'loadImage(_:)' (identifier_name)

/UnitTests/Mocks/MockedWebRepositories.swift:25:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'loadCountryDetails(_:)' (identifier_name)

/UnitTests/Mocks/MockedWebRepositories.swift:48:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'loadImage(_:)' (identifier_name)

/CountriesSwiftUI/Repositories/CountriesWebRepository.swift:49:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'countryDetails(_:)' (identifier_name)

/CountriesSwiftUI/Utilities/APICall.swift:20:10: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'httpCode(_:)' (identifier_name)

/CountriesSwiftUI/System/SystemEventsHandler.swift:80:14: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'showCountryFlag(alpha3Code:)' (identifier_name)

/CountriesSwiftUI/Utilities/Loadable.swift:14:10: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'isLoading(last:)' (identifier_name)

/CountriesSwiftUI/Utilities/Loadable.swift:15:10: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'loaded(_:)' (identifier_name)

/CountriesSwiftUI/Utilities/Loadable.swift:16:10: Identifier Name Violation: Enum element name should only contain alphanumeric characters: 'failed(_:)' (identifier_name)

Hey,

fist off thanks for this insightful repository and article!

When cloning the repository and trying to run it, the application can not connect to the REST API restcountries.eu. Trying to access it via a browser redirects to countrylayer.com. I'm not sure what happened with the API or if it is something that just temporarily happened to me.

Kind regards

AnyCancellable is doing cancel on deinit, it called RAII pattern: https://developer.apple.com/documentation/combine/anycancellable

An AnyCancellable instance automatically calls cancel() when deinitialized

No need to call explicit cancel() on items. CancelBag looks like its not needed. It will cleanup a lot of code

Hello Alex,

Thank you for your architecture example and articles, they are awesome and help me a lot to understand how to work with SwiftUI.

I would like to ask you about more complex navigation in the example. For example, the application has to show CountryDetails from ModalDetailsView. I tried to implement this in fork https://github.com/iomark/clean-architecture-swiftui/tree/test/same_view . As you can see it leads to weird effects. Could you advise how to resolve similar use cases related to using a view that already is presented in view hierarchy? As I understand the application routing state should resolve it in some way.

Hey there,

I am a novice in programming, and I struggle grasping architectures very much. That SwiftUI / Combine are so new does not help a bit, as the dust is definitely not settled yet, and seems like very few really understand how to design with new frameworks.

This project (just as your posts btw) reads very easily, yet I still struggle understanding the core 'why's of the architecture, not to say that I cannot see the whole picture well.

If turned into a tutorial with detailed explanations and rationales describing the architecture, this becomes a goto place to learn how SwiftUI / Combine apps are designed. By tutorial I mean something akin to Apple's (unfortunately very non-informative) multi-step tutorial residing on /tutorials page.

This seems like not an easy task, but maybe other experienced devs can join this initiative.

Thanks!

Hey there, I'm new to iOS development in general but especially Combine/SwiftUI. I've followed your clean architecture and tried to extend it a bit by introducing credentials manager and injecting a token in the WebRepository call.

However, what puzzles me is that if I wrap following code below into a closure I get Generic parameter 'Value' could not be inferred.

session
  .dataTaskPublisher(for: request)
  .requestJSON(httpCodes: httpCodes)

Could you please advise on how to get this solved? This is the whole picture of the function.

func call<Value>(endpoint: APICall, httpCodes: HTTPCodes = .success) -> AnyPublisher<Value, Error>
    where Value: Decodable
{
    do {
        var request = try endpoint.urlRequest(baseURL: baseURL)

        credentialsManager.credentials()
            .map { (credentials: Credentials) in
                let token = credentials.accessToken
                request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
            }
            .map { (_ publisher: AnyPublisher<Value, Error>) in
                session
                    .dataTaskPublisher(for: request) // Generic parameter 'Value' could not be inferred
                    .requestJSON(httpCodes: httpCodes)
            }

    } catch {
        return Fail<Value, Error>(error: error).eraseToAnyPublisher()
    }
}

I am newbie in swiftui.

I am trying to add Pagenation in this feature. If I try to use append as values in loadable<[Model]> , I will get get-only property error.

Model.value.append($0)

How can i fix it?

Hit @nalexn, great job on you repo. I have a question. How and when do you reset your routing states? Currently I have a hierarchy like below: SplashView -> AuthenticationView -> SignUpView -> HomeView I want to log out on home view and go back (move forward) to authentication view. when I change the routing state on home view and go to authentication view, all the previous flags for navigation are true and therefore the view goes forward again and again.