How to reload Container A after update Container B? - swift

Question

I have a ViewController containing a Segmented Control of 3 ContainerViews. Each Container is a ViewController containing a tableView. In CV2, I can choose a row. This row is deleted from CV2 and should be added in CV1.
Before use Segmented Controller, I used tab and table view on each tab were correctly updated. Now, with ContainerView, I don't know how to call the reload. This is my action on segment :
#IBAction func bSegment(_ sender: UISegmentedControl) {
if sender.selectedSegmentIndex == 0 {
UIView.animate(withDuration: 0.0, animations: {
self.listBOutlet.alpha = 1
self.addBOutlet.alpha = 0
self.delBOutlet.alpha = 0
})
} else {
if sender.selectedSegmentIndex == 1 {
UIView.animate(withDuration: 0.0, animations: {
self.listBOutlet.alpha = 0
self.addBOutlet.alpha = 1
self.delBOutlet.alpha = 0
})
} else {
if sender.selectedSegmentIndex == 2 {
UIView.animate(withDuration: 0.0, animations: {
self.listBOutlet.alpha = 0
self.addBOutlet.alpha = 0
self.delBOutlet.alpha = 1
})
}
}
}
}
I tried many things like this to access to viewWillAppear in CV2 :
print(self.children)
var myClass : ListeBEtb = self.????
myClass.ListeB.reloadData()
myClass.viewWillAppear(false)
But I don't know how to call ListeBEtb (CV1) to update it.
In my CV2 :
override func viewWillAppear(_ animated: Bool) {
let recupListeBAddModel = RecupListeBAddModel()
recupListeBAddModel.delegate = self
recupListeBAddModel.downloadItems(id: idEtablissement)
self.ListeB.reloadData()
}
Do you any idea about it ?
Thanks

Answer 1

You have a couple of ways of making this work, with the simplest one using the notification center for start.
Delegate pattern is the other, RxSwift is also an alternative, etc.
For using the notification center, first, define an extension for easier notification handling:
extension Notification.Name {
static let rowDeleted = Notification.Name("rowDeleted")
}
After that, subscribe the the newly created notification in CV1:
NotificationCenter.default.addObserver(self, selector: #selector(rowDeleted), name: .rowDeleted, object: nil)
Note that you need a method called rowDeleted in CV1, or however you want to call it.
Also, make sure to remove yourself as an observer on deinit of CV1:
deinit {
NotificationCenter.default.removeObserver(self)
}
Then, when you make an update in CV2, use something like this:
NotificationCenter.default.post(name: .rowDeleted, object: nil)
This is all assuming you don't need to pass the actual object, but just need an event notification. Object passing is a bit different and better done with delegate pattern, but this is a decent start.

Answer 2

If you're trying to call some logic that exists in the viewWillAppear(_:) function, why not extract that into its own function, call that new function from viewWillAppear(_:), and then you can call that function again when you transition your container views.
So in your container view, it would now look something like this.
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
reloadDataModel()
}
func reloadDataModel() {
let recupListeBAddModel = RecupListeBAddModel()
recupListeBAddModel.delegate = self
recupListeBAddModel.downloadItems(id: idEtablissement)
self.ListeB.reloadData()
}
And then, in your transition code, perhaps just before your animation code, you can call listBOutlet.reloadDataModel(), so it can do the operation as the animation is in progress.