Swift passing data between views

Question

I have a registration page that requires the user to enter: username, password, email, full name. When the register button is clicked the information is sent to my database

What I want to do was to display the username textfield in one view controller, and after that information has been entered, and the username is ready to enter their full name, they can hit a next button on the same view controller and it will go to a different view controller with the full name textfield and so on. I was wondering how I could move through the view controllers without losing the previous view controllers value. At the final view controller, the user will click register

My code for the register button is:

// create new user and send results to mysql database
let url = NSURL (string: "http:/websitename.php")!
let request = NSMutableURLRequest (url: url as URL)
request.httpMethod = "POST"
print ("Request: \(request)")

// body for the request
let body = "user_username=\(usernameTxt.text!.lowercased())&user_password=\(passwordTxt.text!)&user_email=\(emailTxt.text!)&user_fullname=\(fullnameTxt.text!)"

request.httpBody = body.data(using: String.Encoding.utf8)
print("Request: \(request)")
print("RequestBody: \(String(describing: request.httpBody))")

URLSession.shared.dataTask(with: request as URLRequest, completionHandler: {(data:Data?, response: URLResponse?, error: Error?) in
    // no error
    if (error == nil) {
        // send the request to the server
        print("Going to send the request to the server")

        // communicate back to UI
        DispatchQueue.main.async {
            do {
                let json = try JSONSerialization.jsonObject(with: data!, options: .mutableContainers) as? NSDictionary

                guard let parseJSON = json else {
                    print ("There was an error while parsing the JSON data")
                    return
                }

                // get the ID from the JSON struct
                let id = parseJSON["id"]

                // if there is an ID then login
                if (id != nil) {
                    // save user information we received from our host
                    UserDefaults.standard.set(parseJSON, forKey: "parseJSON")
                    user = UserDefaults.standard.value(forKey: "parseJSON") as? NSDictionary

                    // go to tabbar or homepage
                    DispatchQueue.main.async {
                        appDelegate.login()
                    }
                } else {
                    // get main queue to communicate back to user
                    DispatchQueue.main.async(execute: {
                        let message = parseJSON["message"] as! String
                        appDelegate.infoView(message: message, color: colorSmoothRed)
                    })
                }
            } catch {
                // communicate back to UI
                DispatchQueue.main.async(execute: {
                    let message = error as! String
                    appDelegate.infoView(message: message, color: colorSmoothRed)
                })
            }
        }
    } else {
        // get main queue to communicate back to user
        DispatchQueue.main.async(execute: {
            let message = error!.localizedDescription
            appDelegate.infoView(message: message, color: colorSmoothRed)
        })
    }
    // launch prepared session
}).resume()

Answer 1

See Updated Answered At The End (Which I had to add after the comment of questioner):

If you are using UITextField for all the Field like username, password etc.

The recommended way is to check the UITextFieldDelegate method called,

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        if textField == usernameField {
            fullNameField.becomeFirstResponder()
        } else  if textField == fullNameField {
            emailField.becomeFirstResponder()
        } else if textField == emailField {
            passwordField.becomeFirstResponder()
        } else {
            textField.resignFirstResponder()
        }
        usernameField.becomeFirstResponder()
        return true
    }

to solve the next problem, you can change the return key of the keyboard to next

Some Suggestion regarding your question:

How can I set it up so that each textfield has its own view? For example when the user types in the username, they can click next, and it'll go to the next view that displays the full name textfield without losing what the value of the username textfield was?

1. Making a view for each textField will create a bad user experience, plus why you want to increase your redundant code.

2. Try to create as minimal Boilerplate code .

Here is some website to which top developers refers to make great designs:

1. pttrns : Login
2. lovely ui : Login
3. Inspired UI : Login

ANSWER AS PER THE COMMENT OF QUESTIONER:

First, save/retain the previous enter value entered in UserDefaults . So that when the user navigates back to the Previous screen, you can retrieve that value from UserDefaults .