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

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

On July 31, 2014, in iOS, Swfit, by Dipin Krishna

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!

Tagged with: iOS 8 • JSON • Login Screen • Signup Screen • Swift • tutorial • XCode 6

137 Responses to “iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON”

Herolee says:

July 13, 2016 at 11:00 pm

Hello Dipin,
I can not login on our site wordpress also PHP.
Please help,
Thanks,

Reply
- Dipin Krishna says:
  
  July 14, 2016 at 12:19 pm
  
  From the app?
  
  Reply
Rob Dingwall says:

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?

Reply
- Dipin Krishna says:
  
  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.
  
  Reply
erhan says:

April 7, 2016 at 3:46 pm

thank you

Reply
Alam Usmani says:

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.

Reply
Christian says:

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…

Reply
- Dipin Krishna says:
  
  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!
  
  Reply
  - Christian says:
    
    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 says:
    
    August 27, 2015 at 6:33 am
    
    Check if the value exist:
    var email:NSString if((jsonData["email"]) != nil) { email = jsonData["email"] as! NSString }
James says:

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”

Reply
- Dipin Krishna says:
  
  August 7, 2015 at 10:24 am
  
  What’s your xcode version?
  
  Reply
  - Luis says:
    
    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 says:
    
    September 17, 2015 at 9:32 am
    
    Can you make sure you have data returned?
    
    if(urlData != nil) {
    ….
    }

137 Responses to “iOS Login and Signup Screen tutorial : Swift + XCode 6 + iOS 8 + JSON”

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