Cart count not updating in navigation bar while popViewController in swift

Question

I have created custom navigation bar with cart and its count like below code: like this if i call setUpNavigationBar() in all viewcontrollers i am getting navigationbar with cart and count

func setUpNavigationBar(){

self.navigationController?.navigationBar.backgroundColor = CommonColor.navigationColor
self.navigationController?.navigationBar.barTintColor = CommonColor.navigationColor
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.layer.masksToBounds = false

let cartBtn: BadgeButton = BadgeButton(type: .custom)
cartBtn.setImage(#imageLiteral(resourceName: "icon55"), for: .normal)
cartBtn.addAction(for: .touchUpInside) {
print("in cart")
let signupVC = (StoryBoard.driver).instantiateViewController(identifier: "ShoppingCartVC") as! ShoppingCartVC
self.navigationController?.pushViewController(signupVC, animated: true)
}
cartBtn.frame = CGRect(x: 0, y: 0, width: 20, height: 20)
let cartQty = UserDefaults.standard.value(forKey: "cartCount")
cartBtn.badgeText = cartQty as? String
let btnCart = UIBarButtonItem(customView: cartBtn)

self.navigationItem.setRightBarButton(btnCart, animated: true)

}

func setBadgeCountForCart(with : String?){
let badge = self.navigationItem.rightBarButtonItems?.map({$0.customView}).filter({$0 is BadgeButton}).first as? BadgeButton
badge?.badgeText = with
}

but in ShoppingCartVC i don't want navigation bar so, i didn't call setUpNavigationBar in ShoppingCartVC viewdidload

so if remove product from cart and i click back button in ShoppingCartVC then the cartConut is not updating in poped viewcontroller

after remove product i have updated cartCount like below:

class ShoppingCartVC: UIViewController {

 override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(true)
    self.navigationController?.navigationBar.isHidden = true
    self.serviceCall()
}
func serviceCall(){
 self.cartDB = ShoppingCartDetaModel(dictionary: responseData.dict as NSDictionary? ?? NSDictionary())
            
            UserDefaults.standard.set(self.cartDB?.result?.cart?.total_item, forKey: "cartCount")
            self.setUpNavigationBar()

}

@IBAction func back(_ sender: UIButton){
    self.navigationController?.navigationBar.isHidden = false
    self.serviceCall()
    UserDefaults.standard.set(self.cartDB?.result?.cart?.total_item, forKey: "cartCount")
    self.setUpNavigationBar()
    self.navigationController?.popViewController(animated: true)
}

}

where should i change, please do help

score 0 · Answer 1 · answered May 11 '21 at 10:55

0

You need to update the BadgeButton its text property with the updated quantity after you navigated back. You can use different methods for achieving that. The easiest and less clean one is to call self.setUpNavigationBar() in the viewWillAppear method. A cleaner way is to use the NotificationCenter class or a Publisher and post an update every time the quantity changes.

ViewWillAppear: https://developer.apple.com/documentation/uikit/uiviewcontroller/1621510-viewwillappear

NotificationCenter: https://developer.apple.com/documentation/foundation/notificationcenter

Publisher: https://developer.apple.com/documentation/combine/publisher

answered May 11 '21 at 10:55

Lloyd Keijzer

1,229
1
12
22

you know, in ShoppingCartVC `viewWillAppear` i am hiding the navBar.. i know thats the problem.. but i don't want navigationbar in `ShoppingCartVC ` now how to update cartCOunt when i pop.. pls help – learn_swift May 11 '21 at 11:27
i have edited my post with `viewWillAppear` take a look and please do help – learn_swift May 11 '21 at 11:36

Cart count not updating in navigation bar while popViewController in swift

1 Answers1