How to show array in other view SwiftUI-CodePudding

I'm trying to show array values, which I get from API call. I'm making addToCart request in one view and need to show it's result in other view.

class Cart: ObservableObject {

@Published var data: ShoppingCartContent?
@Published var sections: [SectionContent] = []
private var subscriptions = Set<AnyCancellable>() }

extension Cart {

func addToCart(productId: Int, productQty: Int) {
    
    guard let token = UserDefaults.standard.string(forKey: "token") else { return }
    NetworkManager.addProductToCart(token: token, productId: productId, productQty: productQty)
        .sink(
          receiveCompletion: { completion in
              switch completion {
              case .finished:
                  print("finished")
              case .failure(let error):
                  print("AddToCart error", error)
              }
          },
          receiveValue: { value in
              print("Success:", value.success)
              print("Data:", value.data)
              self.data = value.data
              self.sections = value.data.sections
              print("Sections:", self.sections)
          })
        .store(in: &subscriptions) }}

I'm getting data from API, save them in @Published var sections, but I can't show them in other view, print shows it's nil.

struct ShoppingView: View {

@EnvironmentObject var viewModel: Cart

var body: some View {
    ScrollView {
    VStack(alignment: .leading) {
        
    HStack {
        Text("Delivery:")
            .foregroundColor(Color.textFieldGrayColor)
          
        ForEach(viewModel.sections, id: \.self) { section in
            ForEach(section.items, id: \.self) { product in
                Text(product.product_name)
            }
        }
}

}.onAppear {
 print("My cart arr:", cartViewModel.data?.sections)
}
}
}

P.S. ShoppingView - is one of the tabs, I added (environmentObject) in MainView

@EnvironmentObject var viewModel: Cart
ShoppingView().environmentObject(viewModel)

I also tried to access array with @ObservedObject var viewModel = Cart() but it's also shows empty array.

CodePudding user response：

I do not recommend using ShoppingView().environmentObject(Cart()): this will create a new Cart instance every time the view is called. You will finish by re-creating the contents of your variables each time.

What I propose is to replace this call in your original code:

@EnvironmentObject var viewModel: Cart

with:

@StateObject var viewModel = Cart()

This will create a StateObject in the MainView that will be passed to ShoppingView through the environment. Depending on your needs, also let viewModel = Cart() works.

CodePudding user response：

When you are going to inject the view model you have to create an instance

Replace

@EnvironmentObject var viewModel: Cart
ShoppingView().environmentObject(viewModel)

with

ShoppingView().environmentObject(Cart())

The @EnvironmentObject property wrapper is only necessary if you inherit the object.