LengthLimitedTextField.swift

struct LengthLimitedTextField: UIViewRepresentable  {
    var title: String
    @Binding var text: String
    var maxLength: Int
    var onCommit: () -> Void

    init(_ title: String, text: Binding<String>, maxLength: Int = 255, onCommit: @escaping () -> Void) {
        self.title = title
        self._text = text
        self.maxLength = maxLength
        self.onCommit = onCommit
    }

    func makeUIView(context: UIViewRepresentableContext<LengthLimitedTextField>) -> UITextField {
        let textField = UITextField()
        textField.font = UIFont.preferredFont(forTextStyle: .caption1)
        textField.textColor = .lightGray
        textField.delegate = context.coordinator
        textField.placeholder = title
        textField.setContentHuggingPriority(.defaultHigh, for: .vertical)
        textField.setContentHuggingPriority(.defaultLow, for: .horizontal)
        return textField
    }

    func updateUIView(_ uiView: UITextField, context: Context) {
        uiView.text = text
    }

    func makeCoordinator() -> LengthLimitedTextFieldCoordinator {
        return LengthLimitedTextFieldCoordinator($text, maxLength: maxLength, onCommit: onCommit)
    }
}

class LengthLimitedTextFieldCoordinator: NSObject {
    @Binding var text: String
    let maxLength: Int
    let onCommit: () -> Void

    init(_ text: Binding<String>, maxLength: Int, onCommit: @escaping () -> Void) {
        self._text = text
        self.maxLength = maxLength
        self.onCommit = onCommit
    }
}

extension LengthLimitedTextFieldCoordinator: UITextFieldDelegate {
    func textField(_ textField: UITextField,
                   shouldChangeCharactersIn range: NSRange,
                   replacementString string: String) -> Bool {

        guard let currentText = textField.text else { return false }

        var proposedText = currentText
        proposedText.replaceSubrange(Range(range, in: currentText)!, with: string)
        if proposedText.count > maxLength {
            return false
        }

        text = proposedText
        return true
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        onCommit()
        textField.resignFirstResponder()
        return true
    }
}