Follow along at https://www.hackingwithswift.com/100/swiftui/51.
This day covers Part Three of Project 10: CupcakeCorner in the 100 Days of SwiftUI Challenge. (Project 10 files can be found in the directory for Part One.)
It focuses on several specific topics:
- Encoding an ObservableObject class
- Sending and receiving orders over the internet
I took the opportunity with this day to explore how I could fit async networking side effects into a redux/reducer architecture.
Ultimately, this led to creating another view model ObservableObject for the container view -- which handled tapping in to the app state and detecting whether or not an alert should be shown.
final class OrderFormContainerViewModel: ObservableObject {
private var subscriptions = Set<AnyCancellable>()
var store: AppStore
// MARK: - Published Properties
@Published var isShowingAlert = false
// MARK: - Init
init(store: AppStore) {
self.store = store
setupSubscribers()
}
}
// MARK: - Publishers
extension OrderFormContainerViewModel {
// 🔑 Tap into the store's `state` publisher.
private var ordersStatePublisher: AnyPublisher<OrdersState, Never> {
store.$state
.map(\.ordersState)
.eraseToAnyPublisher()
}
... <<More publishers composed from here>> ...
// MARK: - Body
extension OrderFormContainerView {
var body: some View {
NavigationView {
OrderFormView(
viewModel: orderFormViewModel,
buildDestination: {
DeliveryAddressFormView(
viewModel: self.deliveryAddressViewModel,
buildDestination: {
CheckoutView(
viewModel: CheckoutViewModel(
order: self.orderFromFormData
),
onSubmit: self.submitOrder(_:)
)
}
)
}
)
.navigationBarTitle("🧁 Cupcake Corner")
.alert(isPresented: $viewModel.isShowingSaveConfirmationAlert, content: { self.saveConfirmationAlert })
.alert(isPresented: $viewModel.isShowingSaveErrorAlert, content: { self.saveErrorAlert })
}
}
}