if statement executing itself instead of others

Question

I have a code here that, each time I run it, only the if statement which states "All fields are required" works but NOT ONLY when it must be called, it actually runs in place of the others. So whatever I do even when all the fields are complete, I have "All fields are required" as an alert message. Here is the code, all help is appreciated, thank you in advance.

import UIKit

class RegisterPageViewController: UIViewController {


@IBOutlet weak var userEmailTextField: UITextField!
@IBOutlet weak var userPasswordTextField: UITextField!
@IBOutlet weak var repeatPasswordTextField: UITextField!

override func viewDidLoad() {
    super.viewDidLoad()

    // Do any additional setup after loading the view.
}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()
    // Dispose of any resources that can be recreated.
}
@IBAction func registerButtonTapped(_ sender: AnyObject) {

    let userEmail = ""
    let userPassword = ""
    let userRepeatPassword = ""



    // Check for empty fields


    if (userEmail.isEmpty || userPassword.isEmpty || 
userRepeatPassword.isEmpty)
    {
        // Display Alert Message
        displayMyAlertMessage(userMessage:"All fields are required")
        return
    }

    //Check if passwords match
    if (userPassword != userRepeatPassword)
    {
        // Display an alert message
        displayMyAlertMessage(userMessage:"Passwords do not match")
        return
    }


    // Store data
    UserDefaults.standard.set(userEmail, forKey:"userEmail")
    UserDefaults.standard.set(userEmail, forKey:"userPassword")
    UserDefaults.standard.synchronize()


    // Display alert message with confirmation
    _ = UIAlertController(title:"Alert", message:"Registration is 
successfull. Thank you!", 
preferredStyle:UIAlertControllerStyle.alert);

    _ = UIAlertAction(title:"Ok", style:UIAlertActionStyle.default)
    {
        action in
        self.dismiss(animated: true, completion:nil)
    }



 }


func displayMyAlertMessage(userMessage:String)
{

let myAlert = UIAlertController(title:"Alert", message: userMessage, 
preferredStyle:UIAlertControllerStyle.alert);


let okAction = UIAlertAction(title:"Ok", 
style:UIAlertActionStyle.default, handler:nil)

myAlert.addAction(okAction)

self.present(myAlert, animated:true, completion:nil)


}


}

Answer 1

I suspect that this code is not an accurate representation of your implementation. Would you be able to copy and paste the registerButtonTapped(_:) function unedited?

If it is, I would agree with @unmarshalled: It appears that you have declared each of the variables with an empty string as their value. If the code you have posted is implemented exactly as above, that is the cause of your issue.

based on the code you have posted, I would also recommend the following alterations:

• get the email, password & repeatPassword from outside the scope of the function: usually, by just pulling it directly from the UI, most commonly from text fields: i.e. userEmailTextField.text

• extracting your user defaults keys, and any other string literals you have, into a constants file is good practice and avoid any unnecessary misspelling related bugs.

• you don't need to add a handler to a UIAlertAction if all you want it to do is dismiss the alert. UIAlterController will automatically be dismissed automatically: the handler argument has a default value of nil and can be omitted, simply:

  let okayButton = UIAlertAction(title: "Ok", style: .default)

• Generally speaking, you don't want to store a reference to a shared instance. However, within small local scopes its a little cleaner to do so:

  let userDefaults = UserDefaults.standard userDefaults.set(userEmail, forKey:"userEmail") userDefaults.set(userEmail, forKey:"userPassword") userDefaults.synchronize()

Cheers :)

EDIT:

I would suggest extracting the conditional out to a computed property for readability and check if count == 0 rather than isEmpty. The advantage of this is that you can make the computed property more comprehensive, I.e this will check that the strings are not nil or empty. Usually checking the count is enough, but there’s no harm in covering your bases.

As it stands with the current UIKit implementation, UITextField.text can never be nil. That being said, official documentation does not make that guarantee explicitly, so the best way to handle it is to implement it like an optional, below.

So something like:

fileprivate var registrationFormCompleted: Bool {
    guard username = usernameTextfield.text,
    password = passwordTextField.text,
    repeat = repeatPasswordTextField.text, 
    else {
        return false
    }
    return username.count > 0 && 
    password.count > 0 &&
    repeat.count > 0
}

In use it would be:

@IBAction func registerButtonTapped(_ sender: AnyObject) {
    // Check for empty fields
    if !registrationFormCompleted {
        // Display Alert Message
        displayMyAlertMessage(userMessage:"All fields are required")
        return
    }
    //....
}

Answer 2

Do you ever assign any values to userEmail, userPassword, userRepeatPassword? You initialize them as empty at the start of the function, and it looks like their values never change.

Instead of declaring them in the function, try using class level variables, and linking them to your textfields in Storyboard.

@IBOutlet weak var userEmail: UITextField!
@IBOutlet weak var userPassword: UITextField!
@IBOutlet weak var userRepeatPassword: UITextField!

@IBAction func registerButtonTapped(_ sender: AnyObject) {
    // Check for empty fields
    if (self.userEmail.text.isEmpty || self.userPassword.text.isEmpty || self.userRepeatPassword.text.isEmpty) {
        // Display Alert Message
        displayMyAlertMessage(userMessage:"All fields are required")
        return
    }
    ...
}