How do I pass a var from one viewModel to a new viewModel in my .fullScreenCover() View? - swift

Question

I'm building an app with swiftUI & firebase/firestore. I open a fullscreenCover sheet of a product selected from a catalog and the user can add it to a list below it. The product is selected on the previous page, and that is passed onto the .fullScreeenCover, where I'm introducing a new ViewModel for the list.
Where I'm getting confused: How do I pass the product ID passed into this fullScreenCover view into my newly introduced list's viewModel so that I can run the "add to list" function?
ViewModel for my List:
import SwiftUI
import Firebase
class ListViewModel: ObservableObject {
let var product: Product
#Published var userList = [List]()
#Published var list: List
init(list: List) {
self.list = list
}
func fetchList() {
let docRef = Firestore.firestore().collection("List")
guard let uid = AuthViewModel.shared.userSession?.uid else { return }
docRef.whereField("uid", isEqualTo: uid).getDocuments { snapshot, _ in
guard let documents = snapshot?.documents else { return }
self.userList = documents.map({ List(dictionary: $0.data())} )}
}
func AddProductToList(product: Product, list: List) {
let listRef = Firestore.firestore().collection("List").document(list.id).collection("Products")
let productRef = Firestore.firestore().collection("Products").document(product.id)
productRef.getDocument { snapshot, _ in
listRef.document(self.product.id).setData([:]) { _ in
print("\(self.product.title) was saved to \(self.list.name)")
}
}
}
}
Code for .fullScreenCover() sheet View
import SwiftUI
struct ListCoverView: View {
#Binding var isPresented: Bool
let viewModel: LikeViewModel
#StateObject var listViewModel = ListViewModel(list)
var body: some View {
ZStack {
VStack (spacing: 10) {
VStack {
WebImage(url: URL(string: viewModel.product.image))
.resizable()
.frame(width: 220, height: 220)
.padding(.top,10)
Text("\(viewModel.product.title)")
.fontWeight(.bold)
.foregroundColor(.black)
.padding(.horizontal)
Text(viewModel.product.company)
.foregroundColor(.black)
.fontWeight(.bold)
}
.onAppear(perform: {
// Fetch products
listViewModel.fetchList()
})
ScrollView {
VStack {
Button(action: listViewModel.AddProductToList(Product)) {
ForEach(listViewModel.userList){list in
ListRow(list: listViewModel.list, viewModel: listViewModel)
}
}
}
}
}
}
Spacer()
Button(action: {isPresented.toggle()}, label : {
Text("Close")
.font(.system(size: 20))
.foregroundColor(.black)
})
.padding()
}
}
Parent View of the .fullScreenCover()
import SwiftUI
import SDWebImageSwiftUI
struct CardView: View {
let product: Product
#ObservedObject var viewModel: LikeViewModel
#State private var isShowingNewListSheet = false
init(product: Product) {
self.product = product
self.viewModel = LikeViewModel(product: product)
}
var body: some View {
VStack {
WebImage(url: URL(string: product.image))
.resizable()
.aspectRatio(contentMode: .fit)
Text(product.title)
.fontWeight(.bold)
.foregroundColor(.black)
.padding(.horizontal)
Text(product.company)
.foregroundColor(.black)
.fontWeight(.semibold)
.padding(.trailing,65)
HStack{
Button(action: {
viewModel.didLike ? viewModel.UnlikeProduct() : viewModel.LikeProduct()
}, label : {
Image(systemName: viewModel.didLike ? "heart.fill" : "heart")
.resizable()
.frame(width: 20, height: 20)
.foregroundColor(viewModel.didLike ? .red : .black)
})
.padding(.trailing,5)
Button(action: { isShowingNewListSheet.toggle()
}, label : {
Image(systemName: "square.and.arrow.down")
.resizable()
.frame(width: 20, height: 20)
.foregroundColor(.black)
})
.fullScreenCover(isPresented: $isShowingNewListSheet) {
ListCoverView(isPresented: $isShowingNewListSheet, viewModel: viewModel)
}
}
}
.padding(.bottom)
.background(Color(.white))
.cornerRadius(15)
}
}