CODEWITHSUNDEEP
iosswift2swift3
user2091936
user2091936

Reputation: 556

Add Observer and Selector in Swift 3

I am really struggling to understand the new syntax for observers.

Can you help me translate this to Swift 3.

nc.addObserver(self, selector: #selector(MapViewController.locationUpdated(_:)), name: LocationNotification.kLocationUpdated, object: nil)
nc.addObserver(self, selector: #selector(MapViewController.locationAuthorizationStatusChanged(_:)), name: LocationNotification.kAuthorizationStatusChanged, object: nil)
nc.addObserver(self, selector: #selector(MapViewController.locationManagerDidFailWithError(_:)), name: LocationNotification.kLocationManagerDidFailWithError, object: nil)

Many thanks!

Upvotes: 1

Views: 2856

Answers (2)

xivusr
xivusr

Reputation: 419

Remember to make the method accepting the notifications public (if its on a different controller).

And you should also add the processor tag objc so objective-c methods can call it.

Assign Observers:

nc.addObserver(
    self,
    selector: #selector(received(notification:)),
    name: LocationNotification.kLocationUpdated, object: nil
)

Handle notifications:

@objc public func locationUpdated(notification:Notification) {
    //Do something
}

Hope this helps! :-)

Upvotes: 1

nathangitter
nathangitter

Reputation: 9777

The syntax of your code is valid for Swift 3. With this syntax, I am assuming your LocationNotification object looks something like this:

struct LocationNotification {
    static let kLocationUpdated = Notification.Name(rawValue: "LocationUpdated")
    static let kAuthorizationStatusChanged = Notification.Name(rawValue: "AuthorizationStatusChanged")
    static let kLocationManagerDidFailWithError = Notification.Name(rawValue: "LocationManagerDidFailWithError")
}

Upvotes: 1

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