Swift 5 - Navigation Pages - ios

Question

I am just getting to work with Swift 5 and have to update my apps. I use....
let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
self.present(vc, animated: true, completion: nil)
to push users from a sign-in screen to the main app, yet with the updates here's how it looks below (iPhone currently in dark-mode)...
Some questions. What is this functionality definitively called? and how do I go about manipulating it? Say I want to remove it because right now if the user is in the main app they can swipe down and go back to the sign-in screen which would definitely cause problems.
Sign-In View Controller Code
import UIKit
import Firebase
import RealmSwift
class StartViewController: UITableViewController, UITextFieldDelegate {
#IBOutlet weak var email: UITextField!
#IBOutlet weak var password: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
// Check if user is already logged-in so they don't have to sign-in again
checkUserSignIn()
// Setting textfield delegates so user can press enter and go to next textfield
self.email.delegate = self
self.password.delegate = self
let uid = Auth.auth().currentUser?.uid
print(uid)
print("printing the uid here")
}
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// Add a background view to the table view
let backgroundImage = UIImage(named: "startBackground")
let imageView = UIImageView(image: backgroundImage)
self.tableView.backgroundView = imageView
imageView.contentMode = .scaleAspectFill
}
// Check if user is already signed-in, if so push to main app
func checkUserSignIn() {
Auth.auth().addStateDidChangeListener({ (auth, user) in
if (user != nil) {
Database.database().reference().child("users").child((user?.uid)!).observeSingleEvent(of: .value, with: { snapshot in
if snapshot.exists() {
print("user is logged in")
let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
vc.modalPresentationStyle = .overCurrentContext
self.present(vc, animated: true, completion: nil)
}
})
}
})
}
#IBAction func login(_ sender: Any) {
if self.email.text == "" || self.password.text == "" {
//Alert to tell the user that there was an error because they didn't fill anything in the textfields because they didn't fill anything in
let alertController = UIAlertController(title: "Error", message: "Please enter an email and password.", preferredStyle: .alert)
let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alertController.addAction(defaultAction)
self.present(alertController, animated: true, completion: nil)
} else {
Auth.auth().signIn(withEmail: self.email.text!, password: self.password.text!) { (user, error) in
if error == nil {
//Print into the console if successfully logged in
print("You have successfully logged in")
// Proceed To App
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(segue.identifier == "home") {
} else {
print("Problem sending user into nature app")
}
}
} else {
//Tells the user that there is an error and then gets firebase to tell them the error
let alertController = UIAlertController(title: "Error", message: error?.localizedDescription, preferredStyle: .alert)
let defaultAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alertController.addAction(defaultAction)
self.present(alertController, animated: true, completion: nil)
}
}
}
}
#IBAction func createAccount(_ sender: Any) {
// Check user has entered text into fields
guard let email = email.text, email != "",
let password = password.text, password != ""
else {
// Throw alert message to user if fields are empty
let alert = UIAlertController(title: "Registration Error", message: "Please make sure you filled in all of the boxes to complete registration!", preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alert.addAction(okAction)
present(alert, animated: true, completion: nil)
return
}
// Register a new user on Firebase
Auth.auth().createUser(withEmail: email, password: password, completion: { (user, error) in
// Throw registration error / Account could already exist
if let error = error {
let alert = UIAlertController(title: "Registration Error", message: error.localizedDescription, preferredStyle: .alert)
let okAction = UIAlertAction(title: "OK", style: .cancel, handler: nil)
alert.addAction(okAction)
self.present(alert, animated: true, completion: nil)
return
}
guard let userID = user?.user.uid else {
return
}
// Database reference
let databaseRef = Database.database().reference()
// Set user information to firebase data structure
let userInfo = fireUsersData(email: email, profPicString: "", uid: userID)
databaseRef.child("users").child(userID).updateChildValues(userInfo.getUserDictionary(), withCompletionBlock: { (err, databaseRef) in
let UserToAdd = realmUserData()
UserToAdd.email = email
UserToAdd.uid = userID
//UserToAdd.saveDataToRealm()
if err != nil {
// Throw error is problem completeting
let alert = UIAlertController(title: "Error", message: (err?.localizedDescription)! as String, preferredStyle: .alert)
alert.addAction(UIAlertAction(title: "Cancel", style: .cancel, handler: nil))
self.present(alert, animated: true, completion: nil)
}
})
})
// Dismiss keyboard
self.view.endEditing(true)
// Proceed To App
func prepare(for segue: UIStoryboardSegue, sender: Any?) {
if(segue.identifier == "home") {
} else {
print("Problem sending user into nature app")
}
}
}
// END OF FILE
}

Answer 1

Before presenting your ViewController give this option:
let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home")
vc.modalPresentationStyle = .overCurrentContext
self.present(vc, animated: true, completion: nil)
For ignoring dark mode style in didFinishLaunchingWithOptions write this:
if #available(iOS 13.0, *) {
window?.overrideUserInterfaceStyle = .light
}
UPDATE: Replace present to this code:
let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Home") as! UITabBarController
UIApplication.shared.keyWindow?.rootViewController = vc