如何以编程方式正确初始化 ViewController？ loadView() vs init(nibName: nil, bundle: nil)

Question

I'd was wondering what is a proper way of initializing a ViewController from code. No xib or storyboards.

I know two ways. Overriding loadView()

override func loadView() {
    view = UIView()
    commonInit() // some init
}

Or providing init()

init() {
    super.init(nibName: nil, bundle: nil)
    commonInit() // some init
}

required init?(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

If we provide the init and the nib is nil I know we call a default implementation of loadView() which sets our view property.

Which is a more correct way and why?

Answer 1

Separation of concern would advice to use both methods. Override loadView() to init and setup the view, init() to initialise other properties.

loadView() is ran lazily, meaning that it won't be called until something tries to access the .view property of the view controller.

To expand on what init should contain, if your view controller needs network access, it's the place where you should fetch (or inject) your HTTP manager for example.