Swift / code refactoring / how to add parameters to a UIView - ios

Question

I have the following UIView extension to add a background.
extension UIView {
func addBackground() {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: "index_clear")
imageViewBackground.clipsToBounds = true
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}}
I call it with
self.view.addBackground()
What's the best practise to make the extension generic? I want to change the picture like this:
self.view.addBackground("index_clear")
or
self.view.addBackground("other_background_image")
Help is very appreciated.

Answer 1

If you want to avoid breaking any existing implementations within your code, you can take the default parameter approach and do something like this:
extension UIView {
func addBackground(imageName: String = "index_clear") {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: imageName)
imageViewBackground.clipsToBounds = true
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}
}
// You can continue to use it like so
myView.addBackground() // uses index_clear
// or
myView.addBackground("index_not_clear") // uses index_not_clear

Answer 2

Try this :
extension UIView {
func addBackground(imgName : String) {
// screen width and height:
let width = UIScreen.mainScreen().bounds.size.width
let height = UIScreen.mainScreen().bounds.size.height
let imageViewBackground = UIImageView(frame: CGRectMake(0, 0, width, height))
imageViewBackground.image = UIImage(named: imgName)
imageViewBackground.clipsToBounds = true
// you can change the content mode:
imageViewBackground.contentMode = UIViewContentMode.ScaleAspectFill
self.addSubview(imageViewBackground)
self.sendSubviewToBack(imageViewBackground)
}}