viewCode-dataFlow-init.swift

protocol NextCustomViewProtocol where Self: UIView {}

final class DefaultNextCustomView: UIView, NextCustomViewProtocol {
    override init(frame: CGRect = .zero) {
        super.init(frame: frame)
        // setup here
    }

    required init?(coder: NSCoder) {
        fatalError()
    }

    // setup methods goes here...
}


final class NextViewController: UIViewController {
    private let nextCustomView: NextCustomViewProtocol
    private let data: String

    init(data: String, nextCustomView: NextCustomViewProtocol = DefaultNextCustomView()) {
        self.nextCustomView = nextCustomView
        self.data = data
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder aDecoder: NSCoder) {
        fatalError()
    }

    override func loadView() {
        view = nextCustomView
    }
}