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Xcode – Swift NotificationObserver not working with a modally presented ViewController

I’m currently trying to open a modally presented ViewController when pushing a button and send some Data to this modally ViewController by a Notification. The problem is that the NotificationObserver seems not to be working on the modally presented ViewController.

This is how I push the Notification:

let scores = ["Bob": 5, "Alice": 3, "Arthur": 42]
        
NotificationCenter.default.post(Notification(name: .didReceiveData, object: self, userInfo: scores))

This is how I add the Observer

NotificationCenter.default.addObserver(self, selector: #selector(self.onDidReceiveData(_:)), name: .didReceiveData, object: nil)

@objc func onDidReceiveData(_ notification:Notification) {
    if let data = notification.userInfo as? [String: Int]
        {
            for (name, score) in data
            {
                print("(name) scored (score) points!")
            }
        }
}

I’ve already tried adding the NotificationObserver both in viewDidLoad and viewWillAppear, but both options did not work for me.

Does anybody have a solution for this kind of problem?

(I’m using Xcode 12.1, and deploying it on IOS 14.1)

Tags:

2

Answers


  1. Chosen as BEST ANSWER
    0

    Thanks for an answer Andrew, I just solved the issue by refusing the use of Notifications.

    In the prepare function for the StoryboardSegues, i created an instance to the ViewController I'm sending the user to and manipulated a variable in the others ViewControllers class by this instance.

    let destinationViewController = segue.destination as! OtherViewController

destinationViewController.variable = someContent

  2. 0

    First make sure that you subscribe first and only after send a notification. Try to set few breakpoints and check your subscribe / post flow correct.

    Also, as for me, more accurate way to pass data is using viewController’s properties.

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