close modal callback - ios

Question

I have a view with a table on it, on every table cell I can add some data, so I put it in modal which actually is another view. In my modal I have this code
#IBAction func closeModal(_ sender: Any) {
if let amountVal = amount.text {
if let amountInt = Int16(amountVal) {
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let activity = Activity(context: context)
activity.created_at = Date() as NSDate
activity.amount = amountInt
countedObject?.addToActivities(activity)
do {
try context.save()
navigationController?.popViewController(animated: true)
} catch let error {
NSLog(error.localizedDescription)
}
}
}
dismiss(animated: true, completion: nil)
}
So I update core data entity and close modal, but after closing modal the first view was not updated so it does not reflect the changes I made until restart of the simulator. In my first view I have this
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func viewDidAppear(_ animated: Bool) {
populateCountObjects()
}
This works for simple segues but not for modal, what should I use in this case?

Answer 1

So I did it in another way, I added to ViewController this
static var sharedInstace : ViewController?
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
ViewController.sharedInstace = self
}
and in the modal after dismiss method
ViewController.sharedInstace?.didCloseModal()

Answer 2

Posible duplicate : duplicate
You need to use a delegate with a dedicated method
protocol ModalDelegate {
func didCloseModal();
}
In your modal controller class, create an instance of ModalDelegate protocol. And call 'delegate.didCloseModal()' before dismiss
Then make your parent controller implement ModalDelegate protocol
and implement the function didCloseModal like viewDidAppear

Answer 3

Let the system do the work for you. In this case you get a notification when the context is saved.
override func viewDidLoad() {
super.viewDidLoad()
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let center = NotificationCenter.default
center.addObserver(self, selector: #selector(contextDidSave(_:)), name: .NSManagedObjectContextDidSave, object: context)
}
func contextDidSave(_ notification: Notification) {
populateCountObjects()
}
If that doesn't work for you, you can always go lower and get notified whenever an object is changed.
override func viewDidLoad() {
super.viewDidLoad()
let context = (UIApplication.shared.delegate as! AppDelegate).persistentContainer.viewContext
let center = NotificationCenter.default
center.addObserver(self, selector: #selector(contextObjectsDidChange(_:)), name: .NSManagedObjectContextObjectsDidChange, object: context)
}
func contextObjectsDidChange(_ notification: Notification) {
populateCountObjects()
}

Answer 4

I guess your viewDidAppear method isn't called again. Try to use NsNotification to notify your first VC if the context saved and redraw/refresh/reload...etc what you want.