UIBarButton click to set flag value using Swift 4.2 - ios

Question

My scenario, I am having Two UIBarButton with action method, Here, whenever I am clicking Done and Cancel button I am moving to another ViewController. Once user clicked the Done barbutton I need to set some flag value and validate it another ViewController for button clicked or not clicked.
My ViewController One
let barButtonItem = UIBarButtonItem(image: UIImage(named: "backImgs"),
style: .plain,
target: self,
action: #selector(menuButtonTapped))
self.navigationItem.rightBarButtonItem = barButtonItem
#objc fileprivate func menuButtonTapped() { // here I need to set flag value }
My ViewController Two
class ViewControllertwo: UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
//Here need to validate flag values to button clicked or not
}
}

Answer 1

I partially understand your question , in here you need to go with tag concept, for e.g
override func viewDidLoad() {
super.viewDidLoad()
let barButtonItem = UIBarButtonItem(image: UIImage(named: "backImgs"),
style: .plain,
target: self,
action: #selector(menuButtonTapped(_:)))
barButtonItem.tag = 20
let cancelButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action: #selector(menuButtonTapped(_:)))
cancelButton.tag = 10
self.navigationItem.rightBarButtonItem = barButtonItem
self.navigationItem.leftBarButtonItem = cancelButton
}
handle your target function is like
#objc fileprivate func menuButtonTapped(_ sender: UIBarButtonItem) {
// if you dont want the tag concept, use title property for check which button tapped //print("get Tapped button title == \(sender.title)")
//if sender.tag == 20{
// clicked for another VC button, add your segue code here
// }else{
// pressed cancel button
// }
let vcTwo = self.storyboard?.instantiateViewController(withIdentifier: "ViewControllertwo") as! ViewControllertwo
vcTwo.getSelectedTag = sender.tag
self.navigationController?.pushViewController(vcTwo, animated: true)
}
on your VC2 create the one global Int for get the tag where its comes from,
** ViewControllertwo**
class ViewControllertwo : UIViewController {
var getSelectedTag = 0
override func viewDidLoad() {
super.viewDidLoad()
if getSelectedTag == 20 {
//pressed menu Tapped
}
}
}

Answer 2

It's hard to tell from your question, but assuming you are presenting ViewControllerOne from ViewControllerTwo, you're going to want to use the delegate pattern for this. This is similar to the way you use table/collection views, and you are essentially telling ViewControllerTwo to be ViewControllerOne's delegate so that it can react to the buttons being pressed.
Start by creating a protocol that defines the messages that ViewControllerOne can send to its delegate:
protocol ViewControllerOneDelegate: AnyObject {
func viewControllerOneDidTapDone(_ viewController: ViewControllerOne)
func viewControllerOneDidTapCancel(_ viewController: ViewControllerOne)
}
Then extend ViewControllerTwo to implement your protocol:
extension ViewControllerTwo: ViewControllerOneDelegate {
func viewControllerOneDidTapDone(_ viewController: ViewControllerOne) {
// Set your flag or do whatever you need to do on 'Done'.
// Then dismiss viewController.
}
func viewControllerOneDidTapCancel(_ viewController: ViewControllerOne) {
// Dismiss viewController
}
}
In ViewControllerOne, keep the delegate as a weak property and call the delegate methods on button press:
class ViewControllerOne: UIViewController {
weak var delegate: ViewControllerOneDelegate?
#objc private func donePressed() {
delegate?.viewControllerOneDidTapDone(self)
}
#objc private func cancelPressed() {
delegate?.viewControllerOneDidTapCancel(self)
}
}
Lastly, somewhere in ViewControllerTwo, you need to set yourself as ViewControllerOne's delegate. This will likely be when creating ViewControllerOne:
class ViewControllerTwo: UIViewController {
...
private func presentViewControllerOne() {
let viewControllerOne = ViewControllerOne(nibName:nil, bundle: nil)
viewControllerOne.delegate = self
// Present or push viewControllerOne
}
...
}

Answer 3

As I understand your question the solution is -
ViewContorllerOne
class ViewControllerOne : UIViewController {
var isMenubuttonTapped : Bool = false
override func viewDidLoad() {
super.viewDidLoad()
self.actionToPushOnViewControllerTwo()
NotificationCenter.default.addObserver(self, selector: #selector(actioFire), name: NSNotification.Name.init("MenuButtonTapped"), object: nil)
}
//Call from any where in viewControllerOne
func actionToPushOnViewControllerTwo() {
let viewControllerTwo : ViewControllerTwo = self.storyboard?.instantiateViewController(withIdentifier: "ViewControllerTwo") as! ViewControllerTwo
self.present(viewControllerTwo, animated: true, completion: nil)
}
#objc func actioFire(_ notification: Notification) {
print(notification.userInfo!["isMenuButtonTapped"] as Any)
if let isMenuButtonTapped = notification.userInfo!["isMenuButtonTapped"] as? Bool {
self.isMenubuttonTapped = isMenuButtonTapped
}
}
}
ViewControllerTwo
class ViewControllerTwo : UIViewController {
override func viewDidLoad() {
super.viewDidLoad()
let barButtonItem = UIBarButtonItem(image: UIImage(named: "backImgs"),
style: .plain,
target: self,
action: #selector(menuButtonTapped))
self.navigationItem.rightBarButtonItem = barButtonItem
}
#objc fileprivate func menuButtonTapped() {
// here I need to set flag value
self.dismiss(animated: true) {
NotificationCenter.default.post(name: Notification.Name("MenuButtonTapped"),
object: nil,
userInfo:["isMenuButtonTapped": true])
}
}
}
Another Easy Solution is
self.dismiss(animated: true) {
if let tabController = self.presentingViewController as? UITabBarController {
if let navController = tabController.selectedViewController as? UINavigationController {
if let secondTab = navController.viewControllers.first as? HomeViewController {
secondTab.tfData = "YES"
}
} else {
if let secondTab = tabController.selectedViewController as? HomeViewController {
secondTab.tfData = "YES"
}
}
}
}