Multiselect using ObservableObject with child array - Modified from child view through a Binding

SwiftUI-MultiSelect.swift

struct Cheese: Identifiable {
    let name: String
    var isSelected: Bool
    var id: String { name }
}

class ViewModel: ObservableObject {
    @Published var cheeses = [
        Cheese(name: "Brie", isSelected: false),
        Cheese(name: "Cheddar", isSelected: true),
        Cheese(name: "Gouda", isSelected: false),
    ]
}

struct CheeseList: View {
    @ObservedObject var viewModel = ViewModel()

    var body: some View {
        VStack {
            Text("Select Cheeses (\(viewModel.cheeses.filter { $0.isSelected }.count))")
            BindingList(items: $viewModel.cheeses) { cheese in
                CheeseRow(cheese: cheese)
            }
        }
    }
}

struct CheeseRow: View {
    @Binding var cheese: Cheese

    var body: some View {
        Button(action: { self.cheese.isSelected.toggle() }) {
            HStack {
                Text(cheese.isSelected ? "☑" : "☐")
                Text(cheese.name)
            }
        }
    }
}

// ----------- The Reusable Magic ----------- //

struct BindingList<T: Identifiable, V: View>: View {

    @BindableArray var items: Binding<[T]>
    let rowBuilder: ((Binding<T>) -> V)

    var body: some View {
        List($items, rowContent: rowBuilder)
    }
}

extension Binding: Identifiable where Value: Identifiable {
    public var id: Value.ID {
        return wrappedValue.id
    }
}

@propertyWrapper
struct BindableArray<Value> : DynamicProperty {
    @Binding var storage: [Value]

    init(wrappedValue value: Binding<[Value]>) {
        self._storage = value
    }

    public var wrappedValue: Binding<[Value]> {
        get { _storage }
        nonmutating set { storage = newValue.wrappedValue }
    }

    public var projectedValue: [Binding<Value>] {
        var bindings = [Binding<Value>]()
        for (i, item) in storage.enumerated() {
            bindings.append(Binding(
                get: { item },
                set: { self.wrappedValue[i].wrappedValue = $0 }
            ))
        }
        return bindings
    }
}