My code for NSUserDefaults is not working - ios

Question

I am very new to swift. And need your help!
I want that, when the user logs in for the second time , the app should directly take it to the next view controller named CoreView. It should not ask for details, but I don't know why its not working. And it's asking for details everytime the app is launched. Please check the below code. I am not getting any sort of error too. Unless and until the app is killed or logged out, the user should be able to log in directly .
func pref_write()
{
// To write the data to NSUserDefaults
let prefs = NSUserDefaults.standardUserDefaults() // make a reference
print("OTP:\(OTP)")
// Adding values. Creating objects in prefs
prefs.setObject(OTP, forKey: "OTP")
print("check_OTP:\(check_OTP)")
prefs.setObject(U_ID, forKey: "U_ID")
print("Check_U_ID:\(check_U_ID)")
prefs.synchronize()
self.performSegueWithIdentifier("ContinueToCoreView", sender: self)
}
And in the viewDidLoad function:
override func viewDidLoad()
{
super.viewDidLoad()
//Read the data
self.performSegueWithIdentifier("ContinueToCoreView", sender: self)
pref_write()
let prefs = NSUserDefaults.standardUserDefaults()
check_OTP = prefs.objectForKey("OTP")!
check_U_ID = prefs.objectForKey("U_ID")!
prefs.objectForKey("U_ID")
print("prefs:\(prefs)")
prefs.synchronize()
}
Thanks!

Answer 1

Create a class as
class User_Details : NSObject
{
var user_id : String?
var user_otp : String?
var otp_verified : Bool?
init(u_id:String, otp:String?, verified:Bool)
{
super.init()
self.user_id = u_id
self.otp_verified = verified
self.user_otp = otp
}
}
In AppDelegate,
func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool
{
navController = self.window?.rootViewController as? UINavigationController
if self.checkIfUserLoggedIn()
{
let user_details = NSUserDefaults.standardUserDefaults().objectForKey("user_details") as! User_Details
self.moveToNextScreen(user_details)
}
return true
}
//AppDelegate Class or in the class which is globally accessible
func pref_write_user(user_details : User_Details)
{
let prefs = NSUserDefaults.standardUserDefaults()
prefs.setObject(user_details, forKey: "user_details")
prefs.setBool(true, forKey: "is_user_login")
//After saving the OTP for current user, check for otp verified, move to OTP Screen
self.moveToNextScreen(user_details)
}
func moveToNextScreen(user_details : User_Details)
{
if user_details.otp_verified == false
{
// Move to OTP screen
let viewController = self.navController?.storyboard?.instantiateViewControllerWithIdentifier("otpScreen")
self.navController?.pushViewController(viewController!, animated: false)
}
else // Move to Home Screen
{
let viewController = self.navController?.storyboard?.instantiateViewControllerWithIdentifier("homeScreen")
self.navController?.pushViewController(viewController!, animated: false)
}
}
func logoutUser()
{
let prefs = NSUserDefaults.standardUserDefaults()
prefs.setObject(nil, forKey: "user_details")
prefs.setBool(false, forKey: "is_user_login")
}
func checkIfUserLoggedIn() -> Bool
{
let prefs = NSUserDefaults.standardUserDefaults()
if prefs.boolForKey("is_user_login")
{
if let _ = prefs.objectForKey("user_details")
{
return true
}
else
{
//User details not found for some reason, so setting the inital values and return false
self.logoutUser()
}
}
return false
}
Login Class :
Call the API for login by providing the basic credential, get the user_id and user_otp, save them to NSUserDefaults
func requestLoginToServer()
{
//Perform basic server action
....
//In Success Block write this
let appDel = UIApplication.sharedApplication().delegate as! AppDelegate
// pass the values as return by the server
let user_details = User_Details(u_id: "123", otp: "1234", verified: false)
appDel.pref_write_user(user_details)
appDel.moveToNextScreen(user_details)
}

Answer 2

Please try this way. I just rearranged your code.
First it will check the login credentials with in the didload method of initial view controller. If it not there it will call the method pref_write() . Please make sure that the values used in pref_write() method are not nil
override func viewDidLoad()
{
super.viewDidLoad()
let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
// You can give conditions for your need like if(prefs.valueForKey("U_ID") != nil))
// It will check the user defaults whether you already login
if(prefs.valueForKey("OTP") != nil) {
self.performSegueWithIdentifier("ContinueToCoreView", sender: self)
}
else{
pref_write()
}
}
// Make sure the Values are not nil
func pref_write()
{
// To write the data to NSUserDefaults
let prefs = NSUserDefaults.standardUserDefaults() // make a reference
print("OTP:\(OTP)")
// Adding values. Creating objects in prefs
prefs.setObject(OTP, forKey: "OTP")
print("check_OTP:\(check_OTP)")
prefs.setObject(U_ID, forKey: "U_ID")
print("Check_U_ID:\(check_U_ID)")
prefs.synchronize()
self.performSegueWithIdentifier("ContinueToCoreView", sender: self)
}
Hope its working...