CLLocation + Weather(Alamofire) issues - swift

Question

I am trying to use CLLocation to capture longitude and latitude and then use the longitude and latitude in Alamofire to get weather. Every time, the longitude and latitude won't stop updating and the weather data won't print(if you wanna check it out here's an example link of the data: http://forecast.weather.gov/MapClick.php?lat=37.33233141&lon=-122.0312186&FcstType=json)
class SampleViewController: UIViewController, CLLocationManagerDelegate {
var locationManager:CLLocationManager!
var startLocation: CLLocation!
var isFetchingWeather = false
override func viewDidLoad() {
super.viewDidLoad()
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
}
override func viewDidAppear(_ animated: Bool) {
getCurrentLocation()
}
func getCurrentLocation(){
if CLLocationManager.locationServicesEnabled(){
locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
var userLocation:CLLocation = locations[0]
if isFetchingWeather != false{
print("user latitude = \(userLocation.coordinate.latitude)")
print("user longitude = \(userLocation.coordinate.longitude)")
let requestLink = "http://forecast.weather.gov/MapClick.php?lat=\(userLocation.coordinate.latitude)&lon=\(userLocation.coordinate.longitude)&FcstType=json"
print(requestLink)
Alamofire.request(requestLink).validate().responseJSON
{ response in
switch response.result {
case .success(let data):
let json = JSON(data)
self.weatherData = json["data"].arrayValue
for weather in self.weatherData{
let temp = weather["weather"].stringValue
self.weatherString.append(temp)
}
print (self.weatherString)
if self.startLocation == nil {
self.startLocation = userLocation as! CLLocation
self.locationManager.stopUpdatingLocation()
}
case .failure(let error):
print(error)
}
}
}
else{
print("is fetching weather is false")
}
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error)
{
print("Error \(error)")
}
}
Thanks.

Answer 1

You really shouldn't run your weather request inside your location delegate. Instead, get your location in the didUpdateLocations delegate and save it to a var. Next, call stopUpdatingLocation() then call a separate function to make your weather request. Something like this:
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let newLocation = locations.last
//check accuracy and timestamp of location to make sure its not a cached/old location (if you don't care about accuracy or time, you can remove this check)
let timeDiff = newLocation?.timestamp.timeIntervalSinceNow
if timeDiff < 5.0 && (newLocation?.horizontalAccuracy)!<=self.accuracyNeeded{
//stop updating location
self.locationManager.stopUpdatingLocation()
//set currentUserLocation
self.myLocation=newLocation?.coordinate
//call function to get weather
//remove delegate
self.locationManager.delegate = nil
}
}

Answer 2

Set a flag to indicate when you start fetching weather info and do not call Alamofire to fetch weather information if that flag is set. For example, you would declare something like after the line where you declare startLocation:
var isFetchingWeather = false
Then, in locationManagerdidUpdateLocations first check if isFetchingWeather is false. If not, return. Otherwise, fetch the weather info.
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if isFetchingWeather {
return
}
isFetchingWeather = true
// Do the actual weather fetching
}
Of course, you might want to do the actual fetching of the weather after you've gotten a few location updates since the initial ones might not be that accurate :)