CODEWITHSUNDEEP
swiftuiobservedobject
Micheal S. Bingham
Micheal S. Bingham

Reputation: 91

Read value of @ObservedObject only once without listening to changes

Suppose I have some environmental object that stores the states of a user being signed in or not;

class Account: ObservableObject{

    @Published var isSignedIn: Bool = false 

}

I want to conditional display a view if the user is signed in. So, app loads -> RootView(). If user is signed In -> go to Profile, otherwise go to LoginScreen

struct RootView: View {

     @EnvironmentObject private var account: Account
     
     var body: some View {
    
     NavigationStackViews{

 // This is just a custom class to help display certain views with a transition animation 

    if account.isSignedIn{ // I only want to read this ONCE. Otherwise, when this value changes, my view will abruptly change views 
      ProfileView()

} else { SignInView() } 

}
}
    
}

Upvotes: 0

Views: 331

Answers (1)

George
George

Reputation: 30341

Set a @State variable in onAppear(perform:) of the current isSignedIn value. Then use that in the view body instead.

Code:

struct RootView: View {
    @EnvironmentObject private var account: Account
    @State private var isSignedIn: Bool?

    var body: some View {
        NavigationStackViews {
            if let isSignedIn = isSignedIn {
                if isSignedIn {
                    ProfileView()
                } else {
                    SignInView()
                }
            }
        }
        .onAppear {
            isSignedIn = account.isSignedIn
        }
    }
}

Upvotes: 1

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