rhiskey / WelcomeLoginScreen

Login screen logic in UIKit

WelcomeLoginScreen

Task:

Create an application with two screens.

The first screen LoginViewController should be responsible for user authorization. On the second screen, the WelcomeViewController needs to display its name and logout button.

The username on the second screen must be passed when moving from the authorization screen. To do this, implement the prepare method.

When returning to the first screen, the data in the text fields must be cleared. To do this, use the unwind segway.

Pay attention to the keyboard. When entering a username, you must turn off auto-correction and predictive input. When entering a password, the entered characters must be hidden. Work on hiding the keyboard. You can hide the keyboard by tapping on the screen. To do this, you need to override the touchesBegan method:

// Hide keyboard on tap
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super .touchesBegan(touches, with: event)
}

Also pay attention to the fact that the keyboard does not hide the interface elements.

To show or hide the keyboard in the simulator, use the keyboard shortcut Command + K.

---

Optional

Work on the keyboard's Return button

The button can be renamed to Next when entering a username, and to Done when entering a password. Program the operation of this button depending on the location of the cursor. When you click on the Next button, move the cursor to the password field. As long as the password field is empty, the Done button should be disabled. The Done button should duplicate the logic of the Log In button.

To work with the Return button, the LoginViewController class must subscribe to the UITextFieldDelegate protocol and implement the corresponding method:

class LoginViewController: UITextFieldDelegate {
...
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {

    }
}

Also, the class itself must be assigned as a protocol delegate for text fields:

textField.delegate = self

This is done in the viewDidLoad method.

A class can also be assigned as a protocol delegate through the storyboard. To do this, the cursor with the Control key pressed must be moved from the text field to the view controller icon:

And select the delegate item from the context menu:

In this case, you do not need to assign the class as a delegate in the viewDidLoad method either.

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Part 2

To store the username, password, and other information that should be displayed on the screen, you need to create a data model.

Using UITabBarController make some more screens with interesting information about you and your hobbies (summary). Get creative with this process. Use at least three screens for this.

To go to the welcome screen in the prepare(for:) method, you need to create an instance of the UITabBarController class. This instance contains an array of view controllers. To pass data to each view controller from an array, it must be iterated using a loop:

// MARK: Navigation
    override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
        let tabBarController = segue.destination as! UITabBarController
        ...
         for viewController in viewControllers {
            if let welcomeVC = viewController as? WelcomeViewController {
                
            }
        }
        ...
    }

If the tab bar contains a view controller in conjunction with a navigation controller, then to access it, you must first create an instance of the UINavigationController class, and through it you can already access the view controller:

for viewController in viewControllers {
    ...
    } else if let navigationVC = viewController as? UINavigationController {
        let aboutUserVC = navigationVC.topViewController as! AboutMeViewController
    }
}