Accessing rightBarButton function from another ViewController in Swift - ios

Question

I'm trying to access the rightBarButton function for showing cart from an another ViewController, although I can call that function but it won't display any image i.e cart image
Below code show how am i calling this function.
override func viewDidLoad() {
super.viewDidLoad()
// Adding Right Bar Button Item
let rightBarButton = RightBarButton()
rightBarButton.addingRightButton()
}
Below code show about the rightBarButton function.
class RightBarButton {
var storyboard = UIStoryboard()
var navigationItem = UINavigationItem()
var navigationController = UINavigationController()
func addingRightButton() {
let image = UIImage(named: "cart")
let finalImage = resizeImage(image: image!, newWidth: 30)
navigationItem.rightBarButtonItem = FFBadgedBarButtonItem(image: finalImage, target: self, action: #selector(rightButtonTouched))
let button = navigationItem.rightBarButtonItem as? FFBadgedBarButtonItem
cartCount { (cartCount) in
print("Api calling done ...")
print(cartCount)
button?.badge = "\(cartCount)"
}
}
#objc func rightButtonTouched() {
// print("Event Called")
}
func cartCount(completion: #escaping (Int) -> Void) {
// print("Api calling ...")
}
}
If I add this code inside the viewDidLoad() the image will display and the click event work as well.
If you find any solution regarding this code please help!

Answer 1

It doesn't work because navigationItem in your RightBarButton class is not part to of any navigation contoller (as it is manually created and not explicitly attached).
Make the created FFBadgedBarButtonItem instance to be accessible to the view controller so you can add it correctly:
override func viewDidLoad() {
super.viewDidLoad()
// Adding Right Bar Button Item
let rightBarButton = RightBarButton()
rightBarButton.addingRightButton()
navigationItem.rightBarButtonItem = rightBarButton.badgeBarItem // badgeBarItem is the property exposed to the view controller
}
The edited RightBarButton class:
class RightBarButton {
var badgeBarItem: FFBadgedBarButtonItem?
func addingRightButton() {
let image = UIImage(named: "cart")
let finalImage = resizeImage(image: image!, newWidth: 30)
badgeBarItem = FFBadgedBarButtonItem(image: finalImage, target: self, action: #selector(rightButtonTouched))
cartCount { [weak self] cartCount in
print("Api calling done ...")
print(cartCount)
self?.badgeBarItem?.badge = "\(cartCount)"
}
}
#objc func rightButtonTouched() {
// print("Event Called")
}
func cartCount(completion: #escaping (Int) -> Void) {
// print("Api calling ...")
}
}

Answer 2

You need to retreive an instance of needed ViewController with rightBarButton, say neededViewController. And then you can call it like here:
neededViewController.viewDidLoad()
or make another method in neededViewController's class with next content:
func addRB () {
// let rightBarButton = RightBarButton(image: UIImage(named: "imageName"), landscapeImagePhone: UIImage(named: "imageName"), style: .done, target: self, action: nil)
let nc = navigationController
let navBar = nc?.navigationBar
let but = UIBarButtonItem(image: UIImage(named: "imageName"), landscapeImagePhone: UIImage(named: "imageName"), style: .done, target: self, action: nil)
// try to create RightBarButton with defined images and a text and pass it instead of `but`
navBar?.topItem?.setRightBarButton(but, animated: false)
}
and call neededViewController.addRB()