Swift: How to reduce duplicated code when using ViewControllers with identifical buttons - swift

Question

I have the following code on Swift:
class ResenhaMarcasFocinhoController: UIViewController {
var rotateMaisButton:UIButton! = nil
var rotateMenosButton:UIButton! = nil
var lixeiraButton:UIButton! = nil
var confirmarButton:UIButton! = nil
var desfazerVermelhoButton:UIButton! = nil
var desfazerPretoButton:UIButton! = nil
override func viewDidLoad() {
super.viewDidLoad()
inflateView()
}
func inflateView() {
rotateMaisButton = SubViewHelper.getButtonByText(buttonText: "rotate_mais", currentView: view)
rotateMaisButton.addTarget(self, action: #selector(rotateMais_Clicked), for: .touchUpInside)
rotateMenosButton = SubViewHelper.getButtonByText(buttonText: "rotate_menos", currentView: view)
rotateMenosButton.addTarget(self, action: #selector(rotateMenos_Clicked), for: .touchUpInside)
lixeiraButton = SubViewHelper.getButtonByText(buttonText: "lixeira", currentView: view)
lixeiraButton.addTarget(self, action: #selector(lixeira_Clicked), for: .touchUpInside)
confirmarButton = SubViewHelper.getButtonByText(buttonText: "confirmar", currentView: view)
confirmarButton.addTarget(self, action: #selector(confirmar_Clicked), for: .touchUpInside)
desfazerVermelhoButton = SubViewHelper.getButtonByText(buttonText: "desfazer_vermelho", currentView: view)
desfazerVermelhoButton.addTarget(self, action: #selector(desfazerVermelho_Clicked), for: .touchUpInside)
desfazerPretoButton = SubViewHelper.getButtonByText(buttonText: "desfazer_preto", currentView: view)
desfazerPretoButton.addTarget(self, action: #selector(desfazerPreto_Clicked), for: .touchUpInside)
}
func rotateMais_Clicked(sender: UIButton) {
// some code
}
func rotateMenos_Clicked(sender: UIButton) {
// some code
}
func lixeira_Clicked(sender: UIButton) {
// some code
}
func confirmar_Clicked(sender: UIButton) {
// some code
}
func desfazerVermelho_Clicked(sender: UIButton) {
// some code
}
func desfazerPreto_Clicked(sender: UIButton) {
// some code
}
}
The function SubViewHelper.getButtonByText is only a way to assign the button based in the text.
But my problem here is that I have 4 UIViewControllers that contains the same code, because each UIView has the same buttons.
Is it possible to reduce the code on each view controller?

Answer 1

ViewControllers are just classes, and they can participate in inheritance just like any class. So define a base ViewController
class BaseViewController: UIViewController
{
// Common implementation
}
and then inherit from it:
class ViewController1: BaseViewController {
...
}
class ViewController2: BaseViewController {
...
}
...
You can call super for the common code.
An alternative approach would be to define a protocol for your view controllers and provide the common implementation in a protocol extension, however since extensions can't store properties, this might not be the best use for protocols.
If you prefer to use composition rather than inheritance, you can put your common code in a separate class that's not even a view controller that you instantiate in your view controllers, and forward whatever you like to it. This is essentially creating your own kind of delegate:
struct MyViewControllerDelegate // Doesn't have to be a class so I made this a struct
{
/* all those common buttons go here */
func viewDidLoad() { /* common code */ }
}
class ViewController: UIViewController
{
var myDelegate = MyViewControllerDelegate()
override func viewDidLoad()
{
super.viewDidLoad()
myDelegate.viewDidLoad()
// whatever special code you need here.
}
...
}
If you find this cropping up for other sets of view controllers, you might be able to define a protocol for your "ViewControllerDelegates" so they provide a common interface. That would make it easier to generalize the solution.