Hi,

When placing an order for e.g. 8 cupcakes in ContentView, then navigating through placing the order, when i receive the notification back from the server, it does not update the decodedOrder quantity correctly - but it reflects the right kind of cupcake..??

I have checked contentView, and I have made the binding correctly to quantity.

struct ContentView: View {
    //With "State" the order is 'made' here...
    @State private var order = Order()

    var body: some View {
        NavigationStack {
            Form {
                Section {
                    Picker("Select your cake type", selection: $order.type) {
                        ForEach(Order.types.indices, id: \.self) {
                            Text(Order.types[$0])
                        }
                    }

                    Stepper("Number of cakes: \(order.quantity)", value: $order.quantity, in: 3...20)
                }

                Section {
                    Toggle("Any special requests?", isOn: $order.specialRequestEnabled.animation())

                    if order.specialRequestEnabled {
                        Toggle("Add extra frosting", isOn: $order.extraFrosting)
                        Toggle("Add sprinkles", isOn: $order.addSprinkles)
                    }
                }

                Section {
                    Text("Total cost: \(order.price, format: .currency(code: order.localCurrency))")
                }

                Section {
                    NavigationLink("Delivery details") {
                        AddressView(order: order)
                    }
                }
            }
            .navigationTitle("Cupcake Corner - Day 52")
        }
    }
}

I also believe the data upload is also correct. Anyone have any ideas?

   struct CheckOutView: View {
    var order: Order

    @State private var confirmationMessage = ""
    @State private var showingConfirmation = false
    @State private var showingRejection = false
    @State private var rejectionMessage = ""

    var body: some View {
        ScrollView {
            VStack {
                AsyncImage(url: URL(string: "https://hws.dev/img/cupcakes@3x.jpg"), scale: 3) { image in //Downloading an image from the web
                    image
                        .resizable()
                        .scaledToFit()
                } placeholder: {
                    ProgressView()
                }
                .frame(height: 233)

                Text("Your total cost is \(order.price, format: .currency(code: order.localCurrency))")
                    .font(.title)

                Button("Place order") {
                    //make a task to send order to the web
                    Task {
                        await placeOrder()
                    }
                }
                .padding()
            }
        }
        .navigationTitle("check out")
        .navigationBarTitleDisplayMode(.inline)
        .scrollBounceBehavior(.basedOnSize) //Bounce scroll only when contents require it...
        .alert("Thank you!", isPresented: $showingConfirmation) {
            Button("OK") { }
        } message: {
            Text(confirmationMessage)
        }
        .alert("Error", isPresented: $showingRejection) {
            Button("OK") { }
        } message: {
            Text(rejectionMessage)
        }
    }

    //uploading data
    func placeOrder() async {
        //Encode order to JSON
        guard let encoded = try? JSONEncoder().encode(order) else {
            print("Failed to encode order")
            return
        }

        //create the url that we will send the data to
        let url = URL(string: "https://reqres.in/api/cupcakes")! //ideally you want to handle if the url does not exist
        var request = URLRequest(url: url)
        request.setValue("application/json", forHTTPHeaderField: "Content-Type")
        request.httpMethod = "POST" //We want to write/post data

        //actually upload data or catch error
        do {
            let (data, _) = try await URLSession.shared.upload(for: request, from: encoded)

            //Decode the order that we receive back from the server if it was sent
            let decodedOrder = try JSONDecoder().decode(Order.self, from: data)
            confirmationMessage = "Your order for \(decodedOrder.quantity) x \(Order.types[decodedOrder.type].lowercased()) cupcakes is on its way."
            showingConfirmation = true
        } catch {
            rejectionMessage = "There was an error placing your order. please try again."
            showingRejection = true
            print("Check out failed: \(error.localizedDescription)")
        }
    }
}

Thanks.

How do you verify the object in one view is properly packaged and received by another view?

Debugging Technique

Here's a common technique you may want to consider.

You may have structs or classes that contain strings, integers or booleans. Or all three! While you're developing and testing, you may want to just see the contents of an object.

One way to consider is making your object conform to CustomStringConvertible protocol. This protocol requires you to craft a computed var with the name description. You have full freedom how you want to craft this string variable. Maybe you only want three or four of your object's properties. Then benefit is you're able to toss in a print statements here and there to see the contents of your objects before they are sent, after they are updated, and how they are received by other views.

Here's a small code snip. Run this in Playgrounds and have fun.

class Order {
    // Small subset of an actual order object...
    var cakeType:      String
    var quantity:      Int
    var withSprinkles: Bool

    init(cakeType: String, quantity: Int, withSprinkles: Bool = false) {
        self.cakeType      = cakeType
        self.quantity      = quantity
        self.withSprinkles = withSprinkles
    }
}

extension Order: CustomStringConvertible {
    // Custom string convertible requires
    // a var named description.
    // YOU have full freedom to build a custom
    // string out to describe your Order Object

    // Boolean converter
    var sprinkleString : String { withSprinkles ? "Yes" : "None" }
    var description:     String { """
    ========== ORDER ==========
    Flavor:    \(cakeType)
    Quantity:  \(quantity)
    Sprinkles: \(sprinkleString)
    ===========================
    """
    }
}

// Create an object
let partyCupcakes = Order(cakeType: "Vanilla", quantity: 12)

// Toss this in your views to help with validation
print( partyCupcakes.description)

// ========== ORDER ==========
// Flavor:    Vanilla
// Quantity:  12
// Sprinkles: None
// ===========================

Keep Coding!

Please return here and let us know if this helped you zero in on the location of your bug?