It does not read that the setting has changed - swiftui

Question

I have a problem I change the "isDynamic" setting in the "SettingView" and I exit the setting window and the "SongbookView" does not register that the setting has changed. I want to change the search engine depending on what option is selected in the settings. What is the cause of this situation?
SongbookView:
import CoreData
import SwiftUI
struct SongbookView: View {
#State var searchText: String = ""
#State var isSettings: Bool
#ObservedObject var userSettings: UserSettings = UserSettings()
#Environment(\.managedObjectContext) var managedObjectContext
#FetchRequest(
entity: Song.entity(),
sortDescriptors: [NSSortDescriptor(keyPath: \Song.number, ascending: true)]
) var songs: FetchedResults<Song>
var body: some View {
NavigationView{
VStack{
if userSettings.isDynamic == false {
SearchBar(text: $searchText)
} else {
DynamicSearchBar(text: $searchText)
}
List(songs.filter({searchText.isEmpty ? true : removeNumber(str: $0.content!.lowercased()).contains(searchText.lowercased()) || String($0.number).contains(searchText)}), id:\.objectID) { song in
NavigationLink(destination: DetailView(song: song, isSelected: song.favorite)) {
HStack{
Text("\(String(song.number)). ") .font(.headline) + Text(song.title ?? "Brak tytułu")
if song.favorite {
Spacer()
Image(systemName: "heart.fill")
.accessibility(label: Text("To jest ulubiona pieśń"))
.foregroundColor(.red)
}
}.lineLimit(1)
}
}.id(UUID())
.listStyle(InsetListStyle())
}
.padding(.top, 10)
.navigationBarTitleDisplayMode(.inline)
.toolbar {
ToolbarItem(placement: .principal) {
HStack{
Text(String(self.userSettings.isDynamic))
Spacer()
Text("Śpiewnik")
.font(.system(size: 20))
.bold()
Spacer()
Button(action: {
isSettings.toggle()
print(userSettings.isDynamic)
}) {
Image(systemName: "gearshape")
.resizable()
.frame(width: 16.0, height: 16.0)
}
.sheet(isPresented: $isSettings) {
SettingView(isPresented: $isSettings)
}
}
}
}
}
}
func removeNumber(str: String) -> String {
var result = str
let vowels: Set<Character> = ["1", "2", "3", "4", "5", "6", "7", "8", "9"]
result.removeAll(where: { vowels.contains($0) })
return result
}
}
SettingView:
import SwiftUI
struct SettingView: View {
#ObservedObject var userSettings = UserSettings()
#Binding var isPresented: Bool
var body: some View {
NavigationView {
Form {
Toggle("Dynamiczna wyszukiwarka", isOn: $userSettings.isDynamic)
.onChange(of: userSettings.isDynamic) { value in
print(value)
}
Button(action: {
print(userSettings.isDynamic)
isPresented = false
}) {
Text("Test")
}
}
.navigationBarTitle("Ustawienia")
}
}
}
UserSettings:
import Foundation
import Combine
class UserSettings: ObservableObject {
#Published var isDynamic: Bool {
didSet {
UserDefaults.standard.set(isDynamic, forKey: "isSearchDynamic")
}
}
init() {
self.isDynamic = UserDefaults.standard.object(forKey: "isSearchDynamic") as? Bool ?? false
}
}

Answer 1

You're using two different instances of UserSettings. When you update isDynamic on one of those instances, the other, even though it has a reference to UserDefaults has no reason to know that it needs to update.
The easiest solution here is to share a single instance of UserSettings:
struct SongbookView: View {
#State var searchText: String = ""
#State var isSettings: Bool
#ObservedObject var userSettings: UserSettings = UserSettings()
#Environment(\.managedObjectContext) var managedObjectContext
#FetchRequest(
entity: Song.entity(),
sortDescriptors: [NSSortDescriptor(keyPath: \Song.number, ascending: true)]
) var songs: FetchedResults<Song>
var body: some View {
//...
.sheet(isPresented: $isSettings) {
SettingView(userSettings: userSettings,isPresented: $isSettings)
}
//...
}
}
struct SettingView: View {
#ObservedObject var userSettings : UserSettings
#Binding var isPresented: Bool
var body: some View {
//...
}
}
You could also look into property wrappers like #AppStorage (https://www.hackingwithswift.com/quick-start/swiftui/what-is-the-appstorage-property-wrapper) that actually update dynamically when the UserDefaults values change.