SwiftUI -> Thread 1: Fatal error: No observable object of type MyObject.Type found (EnvironmentObject in sheet)

Question

I'm building an app with SwiftUI. When I was trying to display a sheet (previously Modal), this error message appears:

Thread 1: Fatal error: No observable object of type BixiStationCombinedListViewModel.Type found.

A View.environmentObject(_:) for BixiStationCombinedListViewModel.Type may be missing as an ancestor of this view.

This error occurs when I'm using a @State variable to display a modal that includes a Map View using MapKit.

I don't see why and how I should implement a new Environment Object.

Is it because the Station I select when tapping on the CardView should be stored globally and the info should be passed to the dedicated View?

The View handling the @State:

struct CardView: View {
    
    @EnvironmentObject var bixiModel: BixiStationCombinedListViewModel
    @State private var isModalOpen: Bool = false
        
    var station: BixiStationCombinedViewModel
        
    var body: some View {
        
        ZStack(alignment: .leading) {
            
                Card()
                
                StationTextInfo(station: station)

        } .onTapGesture {
            self.isModalOpen = true
            print(self.isModalOpen)
        }
        .sheet(isPresented: self.$isModalOpen) {
            BixiStationDetailView(station: self.station)
        }

    }
}

The View I'm trying to show within the sheet:

struct BixiStationDetailView: View {
    
    @EnvironmentObject var bixiModel: BixiStationCombinedListViewModel
        
    var station: BixiStationCombinedViewModel
    
    var body: some View {
        VStack {
            MapView(coordinate: station.coordinate, name: station.name)        
        }
    }
}

Finally the Object:

class BixiStationCombinedListViewModel: ObservableObject {
    
    init() {
        fetchDataFromApi()
    }
    
    @Published var stationsCombinedList = [BixiStationCombinedViewModel]()
    
    var stationsInformationList = [BixiStationInformationViewModel]()
    var stationsDataList = [BixiStationDataViewModel]()
        
    func fetchDataFromApi() {

        }        
    }
}

How can I get rid of the error message and display the proper View?

Answer 1

You have to pass your environment object to BixiStationDetailView, otherwise it won't have anything to bind to its @EnvironmentObject.

.sheet(isPresented: self.$isModalOpen) {
    BixiStationDetailView(station: self.station)
        .environmentObject(self.bixiModel)
}

Since you're presenting BixiStationDetailView as a sheet, it isn't a subview of your CardView and therefore doesn't inherit its @EnvironmentObject.