iOS: Alert is only triggered once SwiftUI - swift

Question

I have an app that required some alerts. I have implemented the alert trigger with observableObject so that it can be triggered from the my coordinator class. The problem I am having is that the first trigger work and the alert shows. But after the first time no matter how many times I trigger the button the alert does not show.
The view has a webview (UIRepresentable) where when a button is pressed on the webpage the JS triggers the alert in the coordinator class
Relevant parts of code below
MainView with showAlerts class:
import SwiftUI
import WebKit
struct MainContentView: View {
#ObservedObject public var viewAlertsInstance = ShowAlerts()
var body: some View {
ZStack {
SubscriptionViewController(showAlert: viewAlertsInstance)
}
.alert(isPresented: $viewAlertsInstance.showAlert) {
Alert(
title: Text("Important message"),
message: Text("Something"),
dismissButton: .default(Text("Got it!"))
)
}
}
}
class ShowAlerts: ObservableObject {
#Published var showAlert:Bool = false
func displayAlert() {
self.showAlert.toggle()
print(showAlert)
}
}
SubscriptionView including the coordinator:
import SwiftUI
import WebKit
struct SubscriptionViewController: UIViewRepresentable {
#StateObject var showAlert: ShowAlerts
func makeUIView(context: UIViewRepresentableContext<SubscriptionViewController>) -> WKWebView {
let view = WKWebView()
view.navigationDelegate = context.coordinator
DispatchQueue.main.async {
let url = URL(string:"https")!
let request = URLRequest(url: url)
view.load(request)
}
context.coordinator.webView = view
return view
}
func updateUIView(_ uiView: WKWebView, context: UIViewRepresentableContext<SubscriptionViewController>) {
}
func makeCoordinator() -> CoordinatorSubscription {
CoordinatorSubscription(self, showAlert: self.showAlert)
}
typealias UIViewType = WKWebView
}
class CoordinatorSubscription: NSObject, WKNavigationDelegate, WKScriptMessageHandler{
var control: SubscriptionViewController
var showAlert: ShowAlerts
var webView : WKWebView?
init(_ control: SubscriptionViewController, showAlert: ShowAlerts) {
self.control = control
self.showAlert = showAlert
}
func userContentController(_ userContentController: WKUserContentController, didReceive message: WKScriptMessage) {
processReturnedJS(body: message.body as! String)
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
}
func processReturnedJS(body: String) {
//Here should toggle the alert
showAlert.displayAlert()
}
}
In the processReturnedJS function the showAlert.displayAlert() should show the alert every-time the JS is received
Would appreciate any help
Thanks

Answer 1

Swap your
#StateObject and #ObservedObject wrappers
StateObject is for initializing and ObservedObject takes its initial value as a parameter in the initializer per apple documentation.
Then remove
var showAlert: ShowAlerts
In your coordinator and access the variable like this
control.showAlert.displayAlert()

Answer 2

I think you flipped the use of #ObservedObject and #StateObject.
When you find yourself creating a default or a starting value for your object, like you're doing in MainContentView, use #StateObject.
When you are creating your object elsewhere up the view hierarchy and just want your view to observe the object, use #ObservedObject.