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SOLVED: Day 73 Project 14 Challenge | Trailing closure passed to parameter of type 'FormStyleConfiguration' that does not accept a closure

Forums > 100 Days of SwiftUI
@KeyBarreto  HWS+

Hello everyone!

I'm almost finished with BucketList's challenge but I found this error: Trailing closure passed to parameter of type 'FormStyleConfiguration' that does not accept a closure and I thought it had to do with opening in closing { } but I can't find the problem and I can't build the app to see if my solution is correct.

This is my code: 

struct EditView: View {

    @StateObject private var viewModel: EditViewModel

    @Environment(\.dismiss) var dismiss
    var onSave: (Location) -> Void

    var body: some View {
        NavigationView {
            Form {  //The error is here
                Section {
                    TextField("Place name:", text: $viewModel.name)
                    TextField("Description:", text: $viewModel.description)
                }

                Section("Nearby...") {
                    switch $viewModel.loadingState {
                    case .loading:
                        Text("Loading...")
                    case .loaded:
                        ForEach($viewModel.pages, id: \.pageid) { page in
                            /*@START_MENU_TOKEN@*/Text(page.title)/*@END_MENU_TOKEN@*/
                                .font(.headline)
                            + Text(": ")
                            + Text(page.description)
                                .italic()
                        }
                    case .failed:
                        Text("Please try again later.")
                    }
                }
            }
            .navigationTitle("Place details")
            .toolbar {
                Button("Save") {
                    onSave(viewModel.save)
                    dismiss()
                }
            }
            .task {
                await viewModel.fetchNearbyPlaces()
            }
        }
    }

    init(location: Location, onSave: @escaping (Location) -> Void) {
        _viewModel = StateObject(wrappedValue: EditViewModel(location: location))
        self.onSave = onSave
    }
}

3      

@ygeras  

Try to retype Form, and when XCode will show you two prompts Form(_ configuration:) and Form(content:) choose the latter. I think this should solve the issue.

3      

@KeyBarreto  HWS+

Thanks for replying!

I did that but now it appears a new error in the .loading case, which is: Type 'Binding<EditView.LoadingState>' has no member 'loading'. I read on Stack Over Flow and in another Forum Post that it might have to do with how I created the EditViewModel in the EditView --> @StateObject private var viewModel: EditViewModel

In the ContentView, the ViewModel was created like this --> @StateObject private var viewModel = ViewModel(). But I used this logic in the EditViewModel (which I'm not sure about the difference), a Location is required: @StateObject private var viewModel = EditViewModel(location: ).

I'm working in the challenge and I created the ViewModel for the EditView. This is it:

extension EditView {
    enum LoadingState {
        case loading, loaded, failed
    }

    @MainActor class EditViewModel: ObservableObject {

        @Published var name: String
        @Published var description: String

        @Published var loadingState = LoadingState.loading
        @Published var pages = [Page]()

        @Published var location: Location

        init(location: Location) {
          name = location.name
          description = location.description
          self.location = location
        }

        func save() -> Location {
            var newLocation = location
            newLocation.id = UUID()
            newLocation.name = name
            newLocation.description = description

            return newLocation
        }

        func fetchNearbyPlaces() async {
            let urlString = "https://en.wikipedia.org/w/api.php?ggscoord=\(location.coordinate.latitude)%7C\(location.coordinate.longitude)&action=query&prop=coordinates%7Cpageimages%7Cpageterms&colimit=50&piprop=thumbnail&pithumbsize=500&pilimit=50&wbptterms=description&generator=geosearch&ggsradius=10000&ggslimit=50&format=json"

            guard let url = URL(string: urlString) else {
                print("Bar URL: \(urlString)")
                return
            }

            do {
                let (data, _) = try await URLSession.shared.data(from: url)
                let items = try JSONDecoder().decode(Result.self, from: data)
                pages = items.query.pages.values.sorted()
                loadingState = .loaded
            } catch {
                loadingState = .failed
            }
        }

    }

}

3      

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@VulcanCCIT  HWS+

@StateObject private var viewModel: ViewModel

That is correct

Just remove the $ at the switch:

  var body: some View {
    NavigationView {
      Form {
        Section {
          TextField("Place name", text: $viewModel.name)
          TextField("Description", text: $viewModel.description)
        }

        Section("Nearby…") {
          switch viewModel.loadingState { //remove the $ here as you do not need to bind anything, just read the value...
            case .loaded:
              ForEach(viewModel.pages, id: \.pageid) { page in
                    Text(page.title)
                        .font(.headline)
                    + Text(": ") +
                  Text(page.description)
                        .italic()
                }
            case .loading:
                Text("Loading…")
            case .failed:
                Text("Please try again later.")
            }
        }
      }
      .navigationTitle("Place details")
      .toolbar {
        Button("Save") {

          let newLocation = viewModel.createNewLocation()

          onSave(newLocation)
          dismiss()
        }
      }
      .task {
        await viewModel.fetchNearbyPlaces()
      }
    }
  }

  init(location: Location, onSave: @escaping (Location) -> Void) {
    self.onSave = onSave
    _viewModel = StateObject(wrappedValue: ViewModel(location: location))
  }

}

That is what I have...

3      

@KeyBarreto  HWS+

Thanks @VulcanCCIT ! That helped but now I'm getting this error: The compiler is unable to type-check this expression in reasonable time; try breaking up the expression into distinct sub-expressions at the var body: some View { } level.

3      

@VulcanCCIT  HWS+

what happens if you close out of xcode and reopen?

3      

@bobstern  

The error message "The compiler is unable to type-check this expression in reasonable time" is common in Swift. It means the compiler is confused, either because of a syntax error in your code or a bug in the compiler. Usually, refactoring your view into smaller views either will solve the problem or will result in a more informative error message.

In this case, try refactoring Section("Nearby…"){...} into a separate view as described here: https://www.hackingwithswift.com/books/ios-swiftui/view-composition

3      

@VulcanCCIT  HWS+

I do not think the suggestin that @bobstern has is it as I just checked the HackingWithSwift+ solution and your code is almost identical with the exception of the .toolbar { } code, the solution has a slightly different save function but other than that your code is spot on. Just to be sure comment out the code in between the brackets after your Button("Save") { //comment out this code}

but I would suggest first to clean your build folder and or start xcode over...both have solved your issue for me in other code.

Hope that helps!

3      

@VulcanCCIT  HWS+

Actually it does not look like you are passing information correctly to your save function...try this:

.toolbar {
                Button("Save") {
                    let newLocation = viewModel.save()
                    onSave(newLocation)
                    dismiss()
                }

3      

@KeyBarreto  HWS+

Thanks @VulcanCCIT and @bobstern !

I forgot to remove the $ at the ForEach inside the switch. It worked after I deleted it.

4      

@VulcanCCIT  HWS+

@KeyBarreto glad I could help! I didnt catch the $ at the ForEach that has tripped me up before as well!

3      

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