Extracting Observed Object into subview behaves differently than just one view struct. Why? - class

Question

This doesn't work the way I intended it…
When an error occurs in MyClass instance the user is advised to check the settings app and then come back to my app. The next time my app is opened it should just retry by initializing MyClass all over again. If the error persists it will just again display above everything else. (Actually I would like to just fatalError() my app but that isn't best practice, is it?) So I thought I just initialize a new instance of MyClass…
class MyClass: ObservableObject {
static var shared = MyClass()
#Published var errorMsg: String? = nil
func handleError() -> Void {
DispatchQueue.main.async {
self.errorMsg = "Sample Error Message"
}
}
init() {
self.errorMsg = nil
}
}
struct ContentView: View {
#ObservedObject var theObj = MyClass.shared
#Environment(\.scenePhase) private var scenePhase
var body: some View {
ZStack {
VStack {
Text("App when everything is fine")
.onTapGesture {
MyClass.shared.handleError()
}
}
VStack {
if theObj.errorMsg != nil {
VStack {
Spacer()
HStack {
Spacer()
Text(theObj.errorMsg!)
.font(.footnote)
.onTapGesture {
print("theObj.errorMsg! = \(theObj.errorMsg!)")
}
Spacer()
}
Spacer()
}
.background(Color.red)
}
}
}
.onChange(of: scenePhase) { phase in
switch phase {
case .active, .inactive:
if (MyClass.shared.errorMsg != nil) {
MyClass.shared = MyClass()
print("Error cancelled. Retry at next launch...")
}
default:
()
}
}
}
}
As I said: this doesn't work.
Very surprisingly the following variation works… I thought it couldn't work like this but it does. My big question is: WHY does it work like this? Shouldn't this be the same thing? What's the difference that I don't see?
struct ContentView: View {
#Environment(\.scenePhase) private var scenePhase
var body: some View {
ZStack {
VStack {
Text("App when everything is fine")
.onTapGesture {
MyClass.shared.handleError()
}
}
ErrorMsgView()
}
.onChange(of: scenePhase) { phase in
switch phase {
case .active, .inactive:
if (MyClass.shared.errorMsg != nil) {
MyClass.shared = MyClass()
print("Error cancelled. Retry at next launch...")
}
default:
()
}
}
}
}
struct ErrorMsgView: View {
#ObservedObject var theObj = MyClass.shared
var body: some View {
VStack {
if theObj.errorMsg != nil {
VStack {
Spacer()
HStack {
Spacer()
Text(theObj.errorMsg!)
.font(.footnote)
.onTapGesture {
print("theObj.errorMsg! = \(theObj.errorMsg!)")
}
Spacer()
}
Spacer()
}
.background(Color.red)
}
}
}
}
Also I honestly don't understand how do I conclusively kill the MyClass instance I don't need anymore? I do know how to terminate the background tasks that MyClass is running, but is it sufficient to just assign a new instance to the static var shared and the old one is purged?