ios - open - swift present view controller programmatically

Cómo empujar y presentar a UIViewController mediante programación sin segue en iOS Swift 3

Question

Estoy usando este código para push SHOW y MODALMENTE programáticamente en iOS Objective C.
Y ahora quiero saber sobre Swift 3.

NewsDetailsViewController *vc = instantiateViewControllerWithIdentifier:@"NewsDetailsVCID"];
vc.newsObj = newsObj;
//--this(SHOW)
[self.navigationController pushViewController:vc animated:YES];
//-- or this(MODAL)
[self presentViewController:vc animated:YES completion:nil]; 

Gracias.

Answer 1

Con una forma elegante.

Crear un protocolo navegable:

protocol Navigatable {
/// Storyboard name where this view controller exists.
static var storyboardName: String { get }
/// Storyboard Id of this view controller.
static var storyboardId: String { get }
/// Returns a new instance created from Storyboard identifiers.
static func instantiateFromStoryboard() -> Self
}

Cree una implementación de controlador de instancia predeterminada:

/**
Extension of Navigatable protocol with default implementations.
*/
extension Navigatable {
static func instantiateFromStoryboard() -> Self {
let storyboard = UIStoryboard(name: self.storyboardName, bundle: nil)
guard
let viewController = storyboard
.instantiateViewController(withIdentifier: self.storyboardId) as? Self else {
fatalError("Cannot instantiate the controller.")
}
return viewController
}
}

Extiende el UIViewController para impulsar un controlador de vista:

extension UIViewController {
/**
Pushes a view controller of the provided type.
- Parameter viewControllerType: Type of view controller to push.
- Parameter completion: Function to be executed on completion.
Contains the view controller that was pushed when successful and nil otherwise.
*/
func pushViewControllerOfType<T: Navigatable>(viewControllerType: T.Type, completion: (T) -> Void) {
let viewController = T.instantiateFromStoryboard()
if let vc = viewController as? UIViewController {
self.pushViewController(vc, animated: true)
}
completion(viewController)
}
/**
Pushes a view controller of the provided type.
- Parameter viewControllerType: Type of view controller to push.
*/
func pushViewControllerOfType<T: Navigatable>(viewControllerType: T.Type) {
self.pushViewControllerOfType(viewControllerType: viewControllerType) { _ in }
}
}

Luego puede usar el protocolo Navigatable para un controlador de vista específico.

class MySuperViewController {
override func viewDidLoad() {
...
}
// ...
}
extension MySuperViewController: Navigatable {
static var storyboardName: String {
return "Main"
}
static var storyboardId: String {
return "MySuperViewControllerId" // From your story board name Main
}
}
// Instantiate your controller
let vc = MySuperViewController.instantiateFromStoryboard()
// Or
//
// Push your view controller
// testViewController.swift
self.pushViewControllerOfType(viewControllerType: MySuperViewController)

Answer 2

empujar

Gustar

let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = storyboard.instantiateViewControllerWithIdentifier("NewsDetailsVCID") as NewsDetailsViewController
vc.newsObj = newsObj
navigationController?.pushViewController(vc,
animated: true)

o más seguro

 if let viewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NewsDetailsVCID") as? NewsDetailsViewController {
viewController.newsObj = newsObj
if let navigator = navigationController {
navigator.pushViewController(viewController, animated: true)
}
}

presente

 let storyboard = UIStoryboard(name: "Main", bundle: nil)
let vc = self.storyboard?.instantiateViewControllerWithIdentifier("NewsDetailsVCID") as! NewsDetailsViewController
vc.newsObj = newsObj
present(vc!, animated: true, completion: nil) 

o más seguro

 if let vc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "NewsDetailsVCID") as? NewsDetailsViewController
{
vc.newsObj = newsObj
present(vc, animated: true, completion: nil)
}