iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON

by Dipin Krishna
July 31, 2014May 5, 2018

This tutorial will guide you to create a simple app with a Signup and Login screen which takes username and password from the user and then posts it to an url and parse the JSON response.

We will have three view controllers for this project, Signup, Login and Home.

Create a New project. And add the Screens and Segues/transitions.
Home – Check for an existing session, else goto Login
Login Screen – Post data to URL and parse the JSON response.
Signup Screen – Post data to URL and parse the JSON response.
Add Logout to Home Screen

1. Create a New project. And add the Screens and the Segue/transition.

I had issues with Xcode 6.1, not allowing me to create segue between View Controllers. Please see this video for an alternative way to do that:

2. Create Classes Properties And Methods:

Add code to viewDidAppear of HomeVC.swift
to check for existing login, if no session is found then show the login screen.

override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(true)
 
        let prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
        let isLoggedIn:Int = prefs.integerForKey("ISLOGGEDIN") as Int
        if (isLoggedIn != 1) {
            self.performSegueWithIdentifier("goto_login", sender: self)
        } else {
            self.usernameLabel.text = prefs.valueForKey("USERNAME") as NSString
        }
    }

signupTapped in SignupVC.swift:

@IBAction func signupTapped(sender : UIButton) {
        var username:NSString = txtUsername.text as NSString
        var password:NSString = txtPassword.text as NSString
        var confirm_password:NSString = txtConfirmPassword.text as NSString
 
        if ( username.isEqualToString("") || password.isEqualToString("") ) {
 
            var alertView:UIAlertView = UIAlertView()
            alertView.title = "Sign Up Failed!"
            alertView.message = "Please enter Username and Password"
            alertView.delegate = self
            alertView.addButtonWithTitle("OK")
            alertView.show()
        } else if ( !password.isEqual(confirm_password) ) {
 
            var alertView:UIAlertView = UIAlertView()
            alertView.title = "Sign Up Failed!"
            alertView.message = "Passwords doesn't Match"
            alertView.delegate = self
            alertView.addButtonWithTitle("OK")
            alertView.show()
        } else {
 
            var post:NSString = "username=\(username)&password=\(password)&c_password=\(confirm_password)"
 
            NSLog("PostData: %@",post);
 
            var url:NSURL = NSURL(string: "https://dipinkrishna.com/jsonsignup.php")!
 
            var postData:NSData = post.dataUsingEncoding(NSASCIIStringEncoding)!
 
            var postLength:NSString = String( postData.length )
 
            var request:NSMutableURLRequest = NSMutableURLRequest(URL: url)
            request.HTTPMethod = "POST"
            request.HTTPBody = postData
            request.setValue(postLength, forHTTPHeaderField: "Content-Length")
            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
            request.setValue("application/json", forHTTPHeaderField: "Accept")
 
 
            var reponseError: NSError?
            var response: NSURLResponse?
 
            var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)
 
            if ( urlData != nil ) {
                let res = response as NSHTTPURLResponse!;
 
                NSLog("Response code: %ld", res.statusCode);
 
                if (res.statusCode >= 200 && res.statusCode < 300)
                {
                    var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!
 
                    NSLog("Response ==> %@", responseData);
 
                    var error: NSError?
 
                    let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &error) as NSDictionary
 
 
                    let success:NSInteger = jsonData.valueForKey("success") as NSInteger
 
                    //[jsonData[@"success"] integerValue];
 
                    NSLog("Success: %ld", success);
 
                    if(success == 1)
                    {
                        NSLog("Sign Up SUCCESS");
                        self.dismissViewControllerAnimated(true, completion: nil)
                    } else {
                        var error_msg:NSString
 
                        if jsonData["error_message"] as? NSString != nil {
                            error_msg = jsonData["error_message"] as NSString
                        } else {
                            error_msg = "Unknown Error"
                        }
                        var alertView:UIAlertView = UIAlertView()
                        alertView.title = "Sign Up Failed!"
                        alertView.message = error_msg
                        alertView.delegate = self
                        alertView.addButtonWithTitle("OK")
                        alertView.show()
 
                    }
 
                } else {
                    var alertView:UIAlertView = UIAlertView()
                    alertView.title = "Sign Up Failed!"
                    alertView.message = "Connection Failed"
                    alertView.delegate = self
                    alertView.addButtonWithTitle("OK")
                    alertView.show()
                }
            }  else {
                var alertView:UIAlertView = UIAlertView()
                alertView.title = "Sign in Failed!"
                alertView.message = "Connection Failure"
                if let error = reponseError {
                    alertView.message = (error.localizedDescription)
                }
                alertView.delegate = self
                alertView.addButtonWithTitle("OK")
                alertView.show()
            }
        }
 
    }

signinTapped in LoginVC.swift:

@IBAction func signinTapped(sender : UIButton) {
        var username:NSString = txtUsername.text
        var password:NSString = txtPassword.text
 
        if ( username.isEqualToString("") || password.isEqualToString("") ) {
 
            var alertView:UIAlertView = UIAlertView()
            alertView.title = "Sign in Failed!"
            alertView.message = "Please enter Username and Password"
            alertView.delegate = self
            alertView.addButtonWithTitle("OK")
            alertView.show()
        } else {
 
            var post:NSString = "username=\(username)&password=\(password)"
 
            NSLog("PostData: %@",post);
 
            var url:NSURL = NSURL(string: "https://dipinkrishna.com/jsonlogin2.php")!
 
            var postData:NSData = post.dataUsingEncoding(NSASCIIStringEncoding)!
 
            var postLength:NSString = String( postData.length )
 
            var request:NSMutableURLRequest = NSMutableURLRequest(URL: url)
            request.HTTPMethod = "POST"
            request.HTTPBody = postData
            request.setValue(postLength, forHTTPHeaderField: "Content-Length")
            request.setValue("application/x-www-form-urlencoded", forHTTPHeaderField: "Content-Type")
            request.setValue("application/json", forHTTPHeaderField: "Accept")
 
 
            var reponseError: NSError?
            var response: NSURLResponse?
 
            var urlData: NSData? = NSURLConnection.sendSynchronousRequest(request, returningResponse:&response, error:&reponseError)
 
            if ( urlData != nil ) {
                let res = response as NSHTTPURLResponse!;
 
                NSLog("Response code: %ld", res.statusCode);
 
                if (res.statusCode >= 200 && res.statusCode < 300)
                {
                    var responseData:NSString  = NSString(data:urlData!, encoding:NSUTF8StringEncoding)!
 
                    NSLog("Response ==> %@", responseData);
 
                    var error: NSError?
 
                    let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &error) as NSDictionary
 
 
                    let success:NSInteger = jsonData.valueForKey("success") as NSInteger
 
                    //[jsonData[@"success"] integerValue];
 
                    NSLog("Success: %ld", success);
 
                    if(success == 1)
                    {
                        NSLog("Login SUCCESS");
 
                        var prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
                        prefs.setObject(username, forKey: "USERNAME")
                        prefs.setInteger(1, forKey: "ISLOGGEDIN")
                        prefs.synchronize()
 
                        self.dismissViewControllerAnimated(true, completion: nil)
                    } else {
                        var error_msg:NSString
 
                        if jsonData["error_message"] as? NSString != nil {
                            error_msg = jsonData["error_message"] as NSString
                        } else {
                            error_msg = "Unknown Error"
                        }
                        var alertView:UIAlertView = UIAlertView()
                        alertView.title = "Sign in Failed!"
                        alertView.message = error_msg
                        alertView.delegate = self
                        alertView.addButtonWithTitle("OK")
                        alertView.show()
 
                    }
 
                } else {
                    var alertView:UIAlertView = UIAlertView()
                    alertView.title = "Sign in Failed!"
                    alertView.message = "Connection Failed"
                    alertView.delegate = self
                    alertView.addButtonWithTitle("OK")
                    alertView.show()
                }
            } else {
                var alertView:UIAlertView = UIAlertView()
                alertView.title = "Sign in Failed!"
                alertView.message = "Connection Failure"
                if let error = reponseError {
                    alertView.message = (error.localizedDescription)
                }
                alertView.delegate = self
                alertView.addButtonWithTitle("OK")
                alertView.show()
            }
        }
 
    }

logoutTapped in HomeVC.swift

 @IBAction func logoutTapped(sender : UIButton) {
 
        let appDomain = NSBundle.mainBundle().bundleIdentifier
        NSUserDefaults.standardUserDefaults().removePersistentDomainForName(appDomain!)
 
        self.performSegueWithIdentifier("goto_login", sender: self)
    }

Checkout the end result of the tutorial:

Download the full source code using the link below:

It contains the xcode project, php code and the sql file for the whole project.

Thanks, Hope it helps!

140 thoughts on “iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON”

Dipin Krishna February 13, 2021 at 8:52 pm

Xcode Project : SwiftLoginScreen.zip
Php Code : SwiftJsonLoginPHP.zip
arkhers February 11, 2021 at 4:18 am

Hi

Thanks for the lesson, can I access the source code?
wu July 6, 2018 at 10:16 pm

Many thanks for this excellent tutorial.
Dipin Krishna July 14, 2016 at 12:19 pm

From the app?
Herolee July 13, 2016 at 11:00 pm

Hello Dipin,
I can not login on our site wordpress also PHP.
Please help,
Thanks,
Dipin Krishna July 13, 2016 at 8:21 pm

Hi,
can you specify what u mean by “use our own data base instead of using local storage(USER DEFAULTS)”?
Are you try to save the data in a local DB within the app instead of user defaults?
Dipin Krishna July 13, 2016 at 8:18 pm

Hi Rob,

I am creating a tutorial for Login/Signup + auto login using touch id.
But, it on Xcode 8 + objective C.
I will try to add swift code too.

Thanks.
Rob Dingwall July 11, 2016 at 10:58 am

Hi Dipin,
Many thanks for this excellent tutorial.
Is it possible to update it for Xcode version 7.3.1?
erhan April 7, 2016 at 3:46 pm

thank you
Alam Usmani September 18, 2015 at 6:26 am

Thanks a lot your post help me very much, i am recently switch to iOS from dot net.
Dipin Krishna September 17, 2015 at 9:32 am

Can you make sure you have data returned?

if(urlData != nil) {
….
}
Luis September 14, 2015 at 2:35 pm

Hi Dipin! I have the same problem that James, my xcode version is 7 beta.
Nice tutorial
Thanks.

Dipin Krishna August 27, 2015 at 6:33 am

Check if the value exist:

var email:NSString
if((jsonData["email"]) != nil) {
    email = jsonData["email"] as! NSString
}

Christian August 24, 2015 at 6:07 pm

i got an error when i tried to log in
fatal error: unexpectedly found nil while unwrapping an Optional value
xcode show green line at: var lastname:NSString = jsonData[“email”] as! NSString

Dipin Krishna August 23, 2015 at 10:37 pm

You need to pass the info you need in the JSON reply during login.
Then parse the json and save it in the NSUserDefaults.

Eg:

var firstname:NSString = jsonData["firstname"] as NSString
var lastname:NSString = jsonData["lastname"] as NSString
var prefs:NSUserDefaults = NSUserDefaults.standardUserDefaults()
prefs.setObject(username, forKey: "USERNAME")
prefs.setObject(firstname, forKey: "FNAME")
prefs.setObject(lastname, forKey: "LNAME")
prefs.setInteger(1, forKey: "ISLOGGEDIN")
prefs.synchronize()

Hope it helps!

Christian August 23, 2015 at 8:53 am

Helo!
I have one more column named email, how can i show user’s email when user login? And how to store all user’s information to NSUserDefaults with email, firstname, lastname, age…
Dipin Krishna August 7, 2015 at 10:24 am

What’s your xcode version?
James August 7, 2015 at 10:21 am

I keep getting this error: fatal error: “unexpectedly found nil while unwrapping an Optional value”

It is on this line of the code:

“let jsonData:NSDictionary = NSJSONSerialization.JSONObjectWithData(urlData!, options:NSJSONReadingOptions.MutableContainers , error: &error) as! NSDictionary”
Dipin Krishna August 5, 2015 at 2:22 pm

Sorry. Try now.
I had added new fields to the php script on my server for another tutorial.
Chance August 5, 2015 at 2:02 pm

Hey there,

For whatever reason, no matter what I do whenever I create an account (with what I’m sure are unique usernames), it always says “username exists”.

2015-08-05 14:01:52.746 PING[53354:2853979] Response code: 200
2015-08-05 14:01:52.746 PING[53354:2853979] Response ==> {“success”:0,”error_message”:”Username Exist.”}
2015-08-05 14:01:52.756 PING[53354:2853979] Success: 0

I’m using Xcode 6 with iOS 8

Any suggestions?
Dipin Krishna July 17, 2015 at 7:45 am

Hey,

Whats the url you are trying to use?
Try 127.0.0.1 instead of localhost.

Thanks.
Raghu July 17, 2015 at 5:08 am

Hi Dipin,

I always get connection error when trying to connect to localhost php. I am using Xcode 7 beta.

Let me know if any settings I need to apply to make it work ?

Regards,
Raghu
Glauber Felix July 16, 2015 at 4:39 pm

Thanks a lot man and keep up a good work!
Dipin Krishna July 14, 2015 at 8:50 am

Can you check your php logs and figure out what the error is?
Tino Caer July 14, 2015 at 12:25 am

How can I fix this?
Dipin Krishna July 14, 2015 at 12:10 am

Hi,

The php script is not perfect.
The error “username already exists” can be due to some other mysql related error.

Thanks.
Tino caer July 14, 2015 at 12:08 am

Hi, I am wondering how to link the PHP file to the actual app, mine says error: username already exists even though it is completely random! Any help!
Dipin Krishna July 13, 2015 at 10:01 am

Hi,

I have updated the download list with a link to the source for xcode 7 beta.
Glauber Felix July 12, 2015 at 10:34 pm

I got a lot of errors, I am at XCODE 7 beta,

Could you fix it ?

Thanks!
Dipin Krishna July 9, 2015 at 5:36 pm

Hey Keyur,

1. Run the sql file.
2. Create a new user/pass for the DB or you can use the root user.
3. Update the DB host, username and password in the php files.
4. Update the url in the swift code.

That should do.

Thanks.
Keyur July 9, 2015 at 5:06 pm

Thanks for the tutorial… one thing– I want to go ahead and make my own MySQL database to implement this system myself–still on a developmental standpoint.

What all do I need to do (new to databases)?

Do I need to change anything in the .php files you attached?
In the code, do I just need to change the URL’s which link to your website and to mine?

Thanks
Karl Jennings July 7, 2015 at 1:58 pm

This is great stuff. Didn’t use the entire code base but used it to find a problem in my own. I’m new to Swift, it really helped me out!
Dipin Krishna July 6, 2015 at 9:28 am

It looks like your username/password is incorrect.
Nadhif Fadhila July 6, 2015 at 6:02 am

hi im trying to use your db in my web and i get this error

2015-07-06 18:00:20.324 SwiftLoginScreen[880:32379] PostData: username=qwe&password=qwe&c_password=qwe
2015-07-06 18:00:21.813 SwiftLoginScreen[880:32379] Response code: 200
2015-07-06 18:00:21.813 SwiftLoginScreen[880:32379] Response ==>
Warning: mysqli::mysqli(): (28000/1045): Access denied for user ‘DB_USER’@’10.2.1.48’ (using password: YES) in /home/u342872465/public_html/jsonsignup.php on line 21
{“success”:0,”error_message”:”Access denied for user ‘DB_USER’@’10.2.1.48’ (using password: YES)”}
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)

what happen with this? please help me
Dipin Krishna July 5, 2015 at 9:54 am

In this tutorial, it does take you to the “Home” screen after successful login.
Dipin Krishna July 5, 2015 at 9:48 am

Hi,

The username might already exist of the DB.
Or it can be some other error, you can better the php script to catch them.

Thanks.
Rogelio July 2, 2015 at 4:50 pm

Hello, I downloaded the source code and ran it from simulator and my iPhone and when I tap on the sing up button and sign up it brings up a popup menu saying Username Exist, why?

Thank you,

Rogelio
vivek singh June 30, 2015 at 11:28 am

hi, your tutorial is amazing it helps me a lot.
i am new in xcode and swift and wanted to have more tutorial.
i want to know how can we make feed like facebook ios app.
also after login success i wanted to redirect to new viewcontroller so how will i achieve it.please guide.
John Beany June 11, 2015 at 5:16 pm

Thank you so much for fixing the errors in the latest version. It helped me out sooooooooo much! Thank you again!
Dipin Krishna June 10, 2015 at 3:46 pm

Can you make sure you are using the latest source code?

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iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON

1. Create a New project. And add the Screens and the Segue/transition.

2. Create Classes Properties And Methods:

Download the full source code using the link below:

140 thoughts on “iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON”

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