I am having login page how to authenticate the user using coredata database? - ios

Question

I had created a login page and registration page and saved the registered data in core data database but now I need to authenticate the user so that in order to move to another view controller.
here is my code ....
import UIKit
import CoreData
class ViewController: UIViewController {
#IBOutlet weak var usernameTextField: UITextField!
#IBOutlet weak var passwordTextField: UITextField!
#IBOutlet weak var loginButton: UIButton!
#IBOutlet weak var registerButton: UIButton!
var accounts = [Account]()
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
override func viewDidLoad() {
super.viewDidLoad()
self.getAccountData()
loginButton.layer.cornerRadius = 12.0;
registerButton.layer.cornerRadius = 12.0;
usernameTextField.layer.borderWidth = 1;
usernameTextField.layer.borderColor = UIColor.darkGray .cgColor;
usernameTextField.layer.cornerRadius = 5;
usernameTextField.setValue(UIColor.lightGray, forKeyPath: "_placeholderLabel.textColor");
passwordTextField.layer.borderWidth = 1;
passwordTextField.layer.borderColor = UIColor.darkGray.cgColor;
passwordTextField.layer.cornerRadius = 5;
passwordTextField.setValue(UIColor.lightGray, forKeyPath: "_placeholderLabel.textColor");
// Do any additional setup after loading the view, typically from a nib.
}
#IBAction func registerButton(_ sender: Any) {
self.performSegue(withIdentifier: "SecondViewController", sender: nil)
return
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
_ = segue.destination as! SecondViewController
}
#IBAction func loginButton(_ sender: Any) {
if (usernameTextField.text?.isEmpty)! == true
{
let usernamealert = UIAlertController(title: "Warning", message: "Please enter username", preferredStyle: UIAlertControllerStyle.alert)
usernamealert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(usernamealert, animated: true, completion: nil)
}
if (passwordTextField.text?.isEmpty)! == true {
let passwordalert = UIAlertController(title: "Warning", message: "Please enter password", preferredStyle: UIAlertControllerStyle.alert)
passwordalert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(passwordalert, animated: true, completion: nil)
}
let appDelegate = UIApplication.shared.delegate as! AppDelegate
let managedContext = appDelegate.persistentContainer.viewContext
let request = NSFetchRequest<NSFetchRequestResult>(entityName: "Account")
do
{
let results = try context.fetch(request)
if results.count > 0
{
for result in results as! [NSManagedObject]
{
if let firstname = result.value(forKey: "firstName") as? String
{
if(usernameTextField.text == firstname)
{
if let password = result.value(forKey: "lastname") as? String
{
if(passwordTextField.text == password)
{
}else{
let passwordalert = UIAlertController(title: "Warning", message: "Wrong password", preferredStyle: UIAlertControllerStyle.alert)
passwordalert.addAction(UIAlertAction(title: "OK", style: UIAlertActionStyle.default, handler: nil))
self.present(passwordalert, animated: true, completion: nil)
}
}
}
}
}
}
}
}
#IBAction func unwindToView(segue: UIStoryboardSegue){}
func getAccountData() {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
do {
accounts = try context.fetch(Account.fetchRequest())
} catch {
print("Fetching Failed")
}
}

Answer 1

Try like this
call this method from viewWillAppear
self.getAccountData()
and put below code in loginButton() method After the validation done
var username = ""
var passString = ""
var checkRecord = false
for item in accounts
{
username = item.value(forKeyPath: "firstName") as! String
passString = item.value(forKeyPath: "lastname") as! String
if username == usernameTextField.text && passwordTextField.text == passString
{
checkRecord = true;
}
}
if checkRecord == true
{
//succesfull authenticate
}
else
{
//show the error message
}