Usually we have a predefined set of UIBarButtonItem in the project that can be used in the project and multiple times like a left menu button to open a side menu, it can be used in different UIViewControllers also a close button that dismiss the presented view controller.
The classic way is to add these buttons as needed, but this introduce a code duplication and we all want to avoid that.
My come up with an approach, but it's far from being perfect :
enum BarButtonItemType {
case menu, close, notification
}
enum BarButtonItemPosition{
case right, left
}
extension UIViewController {
func add(barButtons:[BarButtonItemType], position: BarButtonItemPosition) {
let barButtonItems = barButtons.map { rightBarButtonType -> UIBarButtonItem in
switch rightBarButtonType {
case .menu:
return UIBarButtonItem(image: UIImage(named:"menu"),
style: .plain,
target: self,
action: #selector(presentLeftMenu(_:)))
case .notification:
return UIBarButtonItem(image: UIImage(named:"notification"),
style: .plain,
target: self,
action: #selector(showNotification(_:)))
case .close:
return UIBarButtonItem(image: UIImage(named:"close"),
style: .plain,
target: self,
action: #selector(dismissController(_:)))
}
}
switch position {
case .right:
self.navigationItem.rightBarButtonItems = barButtonItems
case .left:
self.navigationItem.leftBarButtonItems = barButtonItems
}
}
// MARK: Actions
@objc fileprivate func presentLeftMenu(_ sender:AnyObject) {
self.parent?.presentLeftMenuViewController(sender)
}
@objc fileprivate func dismissController(_ sender:AnyObject) {
self.dismiss(animated: true, completion: nil)
}
@objc fileprivate func showNotification(_ sender:AnyObject) {
let notificationViewController = UINavigationController(rootViewController:NotificationViewController())
self.present(notificationViewController, animated: true, completion: nil)
}
}
and then the usage:
override func viewDidLoad() {
super.viewDidLoad()
self.add(barButtons: [.close], position: .right)
self.add(barButtons: [.menu], position: .left)
}
The limitations of my approach are:
The extension needs to know how to instantiate new view controller (case of notification for example) and what if viewController must be inited with parameters
It assumes that you only want to present a
UIViewControllerNot elegant.
I am sure that there is better way with Swift language and protocol oriented programming that can achieve the intended result with more flexibility, any thoughts ?