#ObservedObject not publishing changes to View - ios

Question

I have a View with a Text that is meant to be updated based on a CountDown() value secondsLeft:
struct TimerCapsule: View {
#ObservedObject var countdown = CountDown()
var body: some View {
Text("\(self.countdown.secondsLeft)")
.font(.system(size: 30))
.foregroundColor(.white)
.frame(width: 100, height: 40)
.padding(EdgeInsets(top: 5, leading: 15, bottom: 5, trailing: 15))
.background(
Capsule()
.fill(Color("Exit"))
.opacity(0.7)
)
.onAppear{
print("Start countdown")
self.countdown.start(from: 30)
}
.onDisappear {
self.countdown.stop()
}
}
}
Here is the CountDown class below. print("Seconds left: \(self.secondsLeft)") successfully prints 30, 29, 28 etc - however, this is not updated in the View above. There is only 1 instance been used in the view above so I'm not sure why it is not being reflected in the Text("\(self.countdown.secondsLeft)") above.
Timer:
class CountDown: ObservableObject {
#Published var secondsLeft = 30
#ObservedObject var block = Block()
var timer: Timer!
func start(from seconds: Int){
self.secondsLeft = seconds
print("start timer")
self.timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true){ _ in
if (self.secondsLeft == 1){
switch self.block.type {
case .match:
self.block.pass()
case .pass:
self.block.pass()
default:
self.block.delete()
}
}
self.secondsLeft -= 1
print("Seconds left: \(self.secondsLeft)")
}
}
func stop(){
self.timer?.invalidate()
}
}
Any idea?
EDIT:
ContentView.swift
struct ContentView: View {
#ObservedObject var auth = UserAuth()
var body: some View {
Group {
if auth.uid != nil { HomeView(auth: auth) } else { LoginView(auth: auth) }
}
}
}
HomeView.swift
struct HomeView: View {
let auth: UserAuth
#ObservedObject var block = Block()
init(auth: UserAuth) {
self.auth = auth
UITabBar.appearance().barTintColor = UIColor.orange
UITabBar.appearance().unselectedItemTintColor = UIColor.white.withAlphaComponent(0.5)
UITabBar.appearance().autoresizesSubviews = true
}
#State var selectedTab = 1
#ObservedObject var locationManager = LocationManager()
var body: some View {
ZStack {
TabView(selection: $selectedTab) {
Settings(auth: auth)
.tabItem {
Image(systemName: "gear")
Text("Settings")
}.tag(0)
ZStack {
MapView(locationManager: locationManager)
Color.black.opacity(self.block.status.opacity).animation(nil)
VStack {
if self.block.type == Type.match || self.block.type == Type.pass {
VStack{
TimerCapsule()
}.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity, alignment: .topLeading)
.padding(.top, 20)
}
Spacer()
if self.block.type == Type.create || self.block.type == Type.delete || self.block.type == Type.pass{
StatusButton()
}
}.padding(40)
.frame(minWidth: 0, maxWidth: .infinity, minHeight: 0, maxHeight: .infinity)
}.edgesIgnoringSafeArea(.top)
.tabItem {
Image(systemName: "location.circle.fill")
Text("Home")
}.tag(1)
ProfileView()
.tabItem {
Image(systemName: "person")
Text("Profile")
}.tag(2)
}.accentColor(Color.white)
.font(.headline)
}
}
}

Answer 1

Can't reproduce any issue. You didn't give enough information to allow the entire code to compile, but if we remove references to all the stuff you left out, we get this:
class CountDown: ObservableObject {
#Published var secondsLeft = 30
var timer: Timer!
func start(from seconds: Int){
self.secondsLeft = seconds
print("start timer")
self.timer = Timer.scheduledTimer(withTimeInterval: 1, repeats: true){ _ in
// don't know what Block is
self.secondsLeft -= 1
print("Seconds left: \(self.secondsLeft)")
}
}
func stop(){
self.timer?.invalidate()
}
}
struct ContentView: View {
#ObservedObject var countdown = CountDown()
var body: some View {
Text("\(self.countdown.secondsLeft)")
.font(.system(size: 30))
.foregroundColor(.white)
.frame(width: 100, height: 40)
.padding(EdgeInsets(top: 5, leading: 15, bottom: 5, trailing: 15))
.background(
Capsule()
.fill(Color(.black)) // don't know what Exit is
.opacity(0.7)
)
.onAppear{
print("Start countdown")
self.countdown.start(from: 30)
}
.onDisappear {
self.countdown.stop()
}
}
}
Copy and paste that into a new SwiftUI project and you'll see that the text does count down.
So if something is preventing that from happening, it's something you didn't show.