SwiftUI, Firebase : How I can handle the completion come from Login result? - firebase

Question

First, this is the AuthService I made
import Foundation
import FirebaseAuth
class AuthService {
static let instance = AuthService()
var isSignIn : Bool = false
func signUpWithEmail(email : String, password : String, completion : #escaping (_ result : Bool) -> ()) {
Auth.auth().createUser(withEmail: email, password: password) { [weak self] result, error in
if let error = error {
print("error to make account")
completion(false)
}
completion(true)
}
}
}
Next one is the View related with the Auth,
import SwiftUI
struct SignUpView: View {
#Environment(\.presentationMode) var presentationMode
#State private var email : String = ""
#State private var password : String = ""
#State private var firstName : String = ""
#State private var lastName : String = ""
#State private var userName : String = ""
#Binding var showMainView : Bool
var body: some View {
NavigationView {
ScrollView {
VStack(alignment : .leading) {
textFieldStyle(title: "E-mail", bindingText: $email)
textFieldStyle(title: "Password", bindingText: $password)
textFieldStyle(title: "Last name", bindingText: $lastName)
textFieldStyle(title: "First name", bindingText: $firstName)
textFieldStyle(title: "User name", bindingText: $userName)
Button(action: {
AuthService.instance.signUpWithEmail(email: email, password: password) { result in
if result {
presentationMode.wrappedValue.dismiss()
showMainView.toggle()
} else {
print("cannot close the view")
}
}
}, label: {
Text("Sign Up")
.font(.title3.bold())
.foregroundColor(.white)
.frame(maxWidth : .infinity)
.frame(height : 60)
.background(.blue)
.cornerRadius(12)
.shadow(color: .gray.opacity(0.2), radius: 12, x: 1, y: 1)
})
}//vst
.padding()
.navigationTitle("Sign Up ")
.navigationBarTitleDisplayMode(.large)
}
}
}
}
And this is the HomeView,
import SwiftUI
import AuthenticationServices
struct HomeView: View {
#State private var showSignUpSheet : Bool = false
#State private var showMainView : Bool = false
var body: some View {
NavigationView {
VStack(spacing : 40) {
HStack {
VStack(alignment : .leading) {
Text("Welcome to")
.font(.title)
.fontWeight(.bold)
Text("CranMarket")
.font(.largeTitle)
.fontWeight(.heavy)
.foregroundColor(.blue)
}
Spacer()
}
.padding()
Text("This is the application for the students and families who want to sell and buy some second use things! Start it right now!")
.padding()
VStack(spacing : 0) {
appleSignInButton
googleSignInButton
emailSignInButton
HStack {
Spacer()
Button(action: {
showSignUpSheet.toggle()
}, label: {
Text("Don't you have account yet?")
.font(.headline)
})
.fullScreenCover(isPresented: $showMainView) {
MainView()
}
.sheet(isPresented: $showSignUpSheet) {
SignUpView(showMainView: $showMainView)
}
}
.padding(.horizontal)
}
}//vst
}//nav
}
}
And this is the picture of result when I failed to sign up,
If you see the picture, the view is not dismissed and navigationLink is triggered.
But I can't understand why that is triggered because the result of signup is 'false' with completion.
How I can handle this situation? and why is the view not working?