Loading user location data for GeoFire query in viewWillAppear - ios

Question

On my main CollectionView (the app home page), I would like to update the locations (i.e. the cells themselves) based on the closest location to the user. I am storing my locations in Firebase and will be using GeoFire and core location in order to properly list out the locations in distance order from the user.
Other posts have said that the best practice for observers involves loading it in viewWillAppear; however, I have been unable to obtain the user's location before this runs and do not have a centered point for my GeoFire query. Most examples related to CoreLocation involve maps or preselected coordinates, but I wasn't planning on using a map within this controller and want to dynamically load based off of user location.
I have researched loading didUpdateLocations within AppDelegate, but have not been able to call that method there either. What is the best way to get user location coordinates before running a GeoFire query when loading that returned data in viewWillAppear or do you need to set a region and check if a user has entered within that region?
var locationDict = [CLLocation]() //using this variable to pass values outside the function to the query
override func viewWillAppear(animated: Bool) {
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
locationManager.startUpdatingLocation()
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let recentLocation = locations[0]
locationDict.append(recentLocation)
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print(error.localizedDescription)
}

Answer 1

There is quite a lot missing in your code, but in short (what works for me):
.requestLocation in viewWillAppear
.startUpdatingLocation() in viewDidAppear. (so twice).
var justStartedUsingMap = true
In didUpdateLocations:
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]){
guard let myLocation:CLLocation = manager.location else {return}
let location:CLLocationCoordinate2D = myLocation.coordinate
let region = MKCoordinateRegion(center: location, span: MKCoordinateSpan(latitudeDelta: 0.12, longitudeDelta: 0.12))
if justStartedUsingMap == true {
self.currentLocationSearch(myLocation)
justStartedUsingMap = false
} else {
locationManager.stopUpdatingLocation()
}
self.map.setRegion(region, animated: true)
}
func currentLocationSearch(_ location: CLLocation) {
// the geofire observer
}