I have a function that listen to Firebase for added and removed childs in my database.
I do a print for the array where I store incoming data from database before observers and one after the observers so to check if the logic is working, and it does. Snapshots append and remove the right object to/from the array.
Now I have the problem that on console I get more than one print per call, in both .childAdded and .childRemoved. It's not random, from fresh start the pattern goes like, 1st add to Firebase gives me 2 prints. And from than it's incremental. 2nd add or 1st remove will give me 3 prints. etc etc..
It's almost like it has a counter..
Removing the observers in viewWillDisappeardoesn't change anything..
In Firebase I store MKAnnotation's coordinates. When I add one annotation I post it, I get it back through the observer's snapshotand I add it to the map. When I remove it I remove it from Firebase and I get a snapshot from .childRemovedobserver and I update the map. What I noticed by putting a breakpoint for each observer is that on the.childRemovedit loops incrementally as the prints. That should mean that the annotation gets added that number of times to the map by the .chilAddedobserver right? I thought I solved this but it's so clear that I haven't. Can you spot the problem here?
Many thanks as usual
Here's the function:
func getAlerts(setCompletion: @escaping (Bool) -> ()) {
self.mapView.removeAnnotations(mapView.annotations)
MapArray.alertNotificationCoordinatesArray.removeAll()
MapArray.userAlertNotificationArray.removeAll()
print(" MapArray.alertNotificationCoordinatesArray before getNewerAlerts is: \(MapArray.alertNotificationCoordinatesArray)")
print(" self.userAlertNotificationArray before getNewerAlerts is: \(MapArray.userAlertNotificationArray)")
ref = Database.database().reference()
ref?.child("Continent").child("Europe").child("Country").child("Italy").child("Region").child("Emilia-Romagna").child("City").child("Bologna").child("Community").child("Alert Notifications").observe(.childAdded, with: { (snapshot) in
// self.mapView.removeAnnotations(self.mapView.annotations) //
print(" added snapshot is: \(snapshot)")
guard let data = snapshot.value as? [String:String] else { return }
// guard let firebaseKey = snapshot.key as? String else { return }
let firebaseKey = snapshot.key
// let date = data!["Date"]
// let time = data!["Time"]
let dataLatitude = data["Latitude"]!
let dataLongitude = data["Longitude"]!
let type = data["Description"]!
let id = Int(data["Id"]!)
let userName = data["user"]!
let doubledLatitude = Double(dataLatitude)
let doubledLongitude = Double(dataLongitude)
let recombinedCoordinate = CLLocationCoordinate2D(latitude: doubledLatitude!, longitude: doubledLongitude!)
let userAlertAnnotation = UserAlert(type: type, coordinate: recombinedCoordinate, firebaseKey: firebaseKey, title: type,id: id!, userName: userName)
MapArray.userAlertNotificationArray.append(userAlertAnnotation) // array of notifications coming from Firebase
MapArray.alertNotificationCoordinatesArray.append(recombinedCoordinate) // array for checkig alerts on route
print(" MapArray.alertNotificationCoordinatesArray after getNewerAlerts is: \(MapArray.alertNotificationCoordinatesArray)")
print(" self.userAlertNotificationArray after getNewerAlerts is: \(MapArray.userAlertNotificationArray)")
setCompletion(true)
self.mapView.addAnnotations(MapArray.userAlertNotificationArray)
})
ref?.child("Continent").child("Europe").child("Country").child("Italy").child("Region").child("Emilia-Romagna").child("City").child("Bologna").child("Community").child("Alert Notifications").observe(.childRemoved, with: { (snapshot) in
print(" self.userAlertNotificationArray before getDeletedAlerts snapshot is: \(MapArray.userAlertNotificationArray)")
print(" MapArray.alertNotificationCoordinatesArray before getDeletedAlerts snapshot is: \(MapArray.alertNotificationCoordinatesArray)")
print(" removed snapshot is: \(snapshot)")
guard let data = snapshot.value as? [String:String] else { return }
let firebaseKey = snapshot.key
// let date = data!["Date"]
// let time = data!["Time"]
let dataLatitude = data["Latitude"]!
let dataLongitude = data["Longitude"]!
let type = data["Description"]!
let id = Int(data["Id"]!)
let userName = data["user"]!
let doubledLatitude = Double(dataLatitude)
let doubledLongitude = Double(dataLongitude)
let recombinedCoordinate = CLLocationCoordinate2D(latitude: doubledLatitude!, longitude: doubledLongitude!)
_ = UserAlert(type: type, coordinate: recombinedCoordinate, firebaseKey: firebaseKey, title: type,id: id!, userName: userName)
MapArray.userAlertNotificationArray.removeAll(where: { ($0.firebaseKey == firebaseKey) }) //remove the alert
MapArray.alertNotificationCoordinatesArray.removeAll(where: { ($0.latitude == recombinedCoordinate.latitude && $0.longitude == recombinedCoordinate.longitude) })
self.mapView.removeAnnotations(self.mapView.annotations)
self.mapView.addAnnotations(MapArray.userAlertNotificationArray)
print(" self.userAlertNotificationArray after getDeletedAlerts snapshot is: \(MapArray.userAlertNotificationArray)")
print(" MapArray.alertNotificationCoordinatesArray after getDeletedAlerts snapshot is: \(MapArray.alertNotificationCoordinatesArray)")
setCompletion(true)
})
}
