UserDefaults to store a button selection from an array - ios

Question

Struggling to figure out how to store the selection of a button here and hoping somebody could help. I am first making a db query to return a list of results, each item has a button that when clicked, it will always show that they clicked it. The way it is currently working, while I'm on the page, I can click to add, which works and writes to the db, and when clicked it changes to the Undo button, which also works the way I want it to, but as soon as I leave this view and come back, it reverts back to the original with the "Add" button. If a user presses Add, i would like it to persist and always show the Undo button when the user comes back to this screen. Any help would be amazing as I'm quite new to this.
Code below:
Main View
struct AdditemView: View {
let movie: Movie
#State var movieitems = [MovieitemsModel]()
#State var movieID = ""
#State var selection = ""
var body: some View {
VStack {
ForEach(movieitems.indices, id: \.self) { i in
HStack {
Text(movieitems[i].name)
Spacer()
if movieitems[i].selected == false {
Button(action: {
self.selection = movieitems[i].name
self.movieitems[i].selected = true
self.yesitem()
}) {
Text("Add")
}
} else {
HStack {
Text("Added!")
Button(action: {
self.selection = movieitems[i].name
self.movieitems[i].selected = false
self.undoitem()
}) {
Text("Undo")
}
}
}
}
Divider()
}
}
.onAppear {
self.movieID = "\(movie.id)"
fetchitems()
}
}
}
func fetchitems() {
let db = Firestore.firestore()
db.collection("movies").document("\(self.movieID)").collection("items").getDocuments { NewQuerySnapshot, error in
guard let documents = NewQuerySnapshot?.documents else {
print("No Documents")
return
}
movieitems = documents.map { (NewQueryDocumentSnapshot) -> MovieitemsModel in
let data = NewQueryDocumentSnapshot.data()
let name = data["name"] as? String ?? ""
let yes = data["yes"] as? Int?
let no = data["no"] as? Int?
return MovieitemsModel(name: name, yes: yes! ?? 0, no: no! ?? 0)
}
}
}
func yesitem() {
let db = Firestore.firestore()
db.collection("movies").document(movieID).collection("items").document("\(self.selection)").updateData([AnyHashable("yes"): FieldValue.increment(Int64(1))])
}
func undoitem() {
let db = Firestore.firestore()
db.collection("movies").document(movieID).collection("items").document("\(self.selection)").updateData([AnyHashable("yes"): FieldValue.increment(Int64(-1))])
}
Items Model
struct MovieitemsModel: Identifiable {
var id: String = UUID().uuidString
var name: String
var yes: Int
var no: Int
var selected:Bool = false
}

Answer 1

One way of doing this is writing another function that saves the movies data back to the database and call it in each button’s action handler.
// Example button
Button(action: {
self.selection = movieitems[i].name
self.movieitems[i].selected = true
self.undoitem()
self.saveItems()
}) {
Text("Undo")
}
// The save method
func saveItems():
// Your Firebase saving code here