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SOLVED - Confusion with Project 14 - Introduction to MVVM

Forums > 100 Days of SwiftUI

That will of course break a lot of code, but the fixes are easy – just add viewModel in various places. So, locations becomes $viewModel.locations, and selectedPlace becomes viewModel.selectedPlace.

Except it's not easy. I added "viewModel" to all the instances of "locations" and "selectedPlace" but I'm getting errors on the Annotation block. Here's the relevant part of my code:

        MapReader { proxy in
            Map(initialPosition: startPosition) {
                ForEach($viewModel.locations) { location in
                    Annotation(location.name, coordinate: location.coordinate) {
                        Image(systemName: "star.circle")
                            .resizable()
                            .foregroundStyle(.red)
                            .frame(width: 44, height: 44)
                            .background(.white)
                            .clipShape(.circle)
                            .onLongPressGesture {
                                viewModel.selectedPlace = location
                            }
                    }
                }
            }
            .onTapGesture { position in
                if let coordinate = proxy.convert(position, from: .local) {
                    let newLocation = Location(id: UUID(), name: "New location", description: "", latitude: coordinate.latitude, longitude: coordinate.longitude)
                    viewModel.locations.append(newLocation)
                }
            }
            .sheet(item: $viewModel.selectedPlace) { place in
                EditView(location: place) { newLocation in
                    if let index = viewModel.locations.firstIndex(of: place) {
                        viewModel.locations[index] = newLocation
                    }
                }
            }
        }

The errors are:

Cannot assign to property: 'coordinate' is a get-only property

Cannot assign value of type 'Binding<[Location]>.Element' (aka 'Binding<Location>') to type 'Location'

1      

Remove $ aka binding in this line

ForEach(viewModel.locations)

1      

Well that's very strange. The article seems to be wrong. Thank you.

1      

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