Firebase automatic login on iOS - ios

Question

Is there a better way to make a user automatically login to the app as long as they have logged in in the past; other than saving their login details directly to the storage which may be insecure?
Thanks
PS: I'm using Firebase and Swift for iOS
EDIT: Here's the code
import UIKit
import Firebase
class loginVC: UIViewController {
#IBOutlet weak var emailTextField: UITextField!
#IBOutlet weak var passwordTextField: UITextField!
#IBOutlet weak var errorLabel: UILabel!
override func viewDidAppear(animated: Bool) {
automaticLogin()
}
#IBAction func loginTapped(sender: AnyObject) {
errorLabel.text = ""
FIRAuth.auth()?.createUserWithEmail(emailTextField.text!, password: passwordTextField.text!, completion: {
user, error in
if error != nil {
FIRAuth.auth()?.signInWithEmail(self.emailTextField.text!, password: self.passwordTextField.text!, completion: { (user, error) in
if error == nil {
self.login()
} else if error != nil {
self.errorLabel.text = ("Invalid email address or password")
print(error)
}
})
} else {
print("user created")
self.login()
print(user?.displayName)
}
})
}
#IBAction func forgotPasswordTapped(sender: AnyObject) {
let email = emailTextField.text
errorLabel.text = ""
FIRAuth.auth()?.sendPasswordResetWithEmail(email!) { error in
if error != nil {
self.errorLabel.text = ("Invalid email address")
print(error)
} else {
self.errorLabel.text = ("Password reset email successfully sent")
print("password reset email sent")
}
}
}
func login() {
FIRAuth.auth()?.signInWithEmail(emailTextField.text!, password: passwordTextField.text!, completion: {
user, error in
if error != nil {
self.errorLabel.text = ("Invalid email address or password")
print(error)
} else {
print("login successful")
self.checkIfUserIsNew()
}
})
}
func checkIfUserIsNew() {
if FIRAuth.auth()?.currentUser?.displayName != nil || FIRAuth.auth()?.currentUser?.displayName == "" {
self.performSegueWithIdentifier("showChatVC", sender: self)
} else {
self.performSegueWithIdentifier("showOptionsVC", sender: self)
}
}
func automaticLogin() {
FIRAuth.auth()?.addAuthStateDidChangeListener { auth, user in
if user == user {
print("still signed in")
} else {
print("not signed in")
}
}
}
I also used this to logout the user:
#IBAction func logOutTapped(sender: AnyObject) {
try! FIRAuth.auth()?.signOut()
performSegueWithIdentifier("showLoginVC", sender: self)
print(FIRAuth.auth()?.currentUser?.displayName)
}

Answer 1

You might want to use NSUserDefaults. To do this in your login() function you might want to save your user's data once they signed in or create an account. Inside your login function you can start by creating new variable to grab your user's email / password.
let userDefaults = UserDefaults.standard
userDefaults.setValue(self.emailField.text!, forKey: "email")
userDefaults.setValue(self.passField.text!, forKey: "password")
Next, you also need to implement a new function called viewWillAppear, which will be called before the view controller. And you might also put some arguments inside your login function.
override func viewWillAppear(_ animated: Bool) {
let userDefaults = UserDefaults.standard
if userDefaults.string(forKey: "email") != nil {
let email = userDefaults.string(forKey: "email")
let password = userDefaults.string(forKey: "password")
login(email: email!, password: password!)
}
}
the if statement will check wether your user already registered their email account or not yet. Lastly you need to update your login function to have two parameters, to pass in the email and password of the user.