IOS combine framework sample

gistfile1.txt

import UIKit
import Combine

class ViewModel {
    var updateLabel: ((String?) -> Void)?
    var textString: String? {
        didSet {
            updateLabel?(textString)
        }
    }
}
class ViewController: UIViewController {

    @IBOutlet var mTextField: UITextField!
    @IBOutlet var mLabel: UILabel!
    var sub: AnyCancellable?
    var model = ViewModel()
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Update UI
        model.updateLabel = { val in
            self.mLabel.text = val
        }
        
        // With FRP
        sub = NotificationCenter.default
            .publisher(for: UITextField.textDidChangeNotification, object: mTextField)
            .map({ ($0.object as! UITextField).text } )
            .receive(on: DispatchQueue.main)
            .assign(to: \ViewModel.textString, on: model)
            
                
        
        // Without FRP
        mTextField.addTarget(self, action: #selector(textChanged(_:)), for: .editingChanged)
    }

    // Without FRP
    @objc func textChanged(_ textField: UITextField) {
        model.textString = textField.text
    }
}