I'm trying to render a Google map with the user current location but it only renders the default location(around Europe area) no matter what I do. Since I am new to Swift, I am not sure how to debug this and want to ask here to figure out what I need to do.
Swift code
import UIKit
import GoogleMaps
class ViewController: UIViewController {
#IBOutlet weak var mapView: GMSMapView!
var locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self
locationManager.requestWhenInUseAuthorization()
}
}
extension ViewController: CLLocationManagerDelegate {
private func locationManager(manager: CLLocationManager, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
if status == .authorizedWhenInUse {
locationManager.startUpdatingLocation()
mapView.isMyLocationEnabled = true
mapView.settings.myLocationButton = true
}
}
private func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if let location = locations.first {
mapView.camera = GMSCameraPosition(target: location.coordinate, zoom: 15, bearing: 0, viewingAngle: 0)
locationManager.stopUpdatingLocation()
}
}
}
Use did change autorization delegate of location manager where you should use
start updating location then
Remove private key before delegate methods and put below properties in did update location delegate methods. Remove stop update location method.
func locationManager(_ manager: CLLocationManager,
didChangeAuthorization status: CLAuthorizationStatus) {
switch status {
case .authorizedAlways, .authorizedWhenInUse:
self.locationManager.startUpdatingLocation()
break
case .denied, .restricted:
self.disableLocationRelatedFeatures()
break
// Do nothing otherwise.
default: break
}
}
self.mapView.isMyLocationEnabled = true
self.mapView.settings.myLocationButton = true
Related
class LocationManager: NSObject, CLLocationManagerDelegate {
private var onLocation: ((CLLocationCoordinate2D) -> Void)?
private let manager: CLLocationManager
override init() {
manager = CLLocationManager()
super.init()
manager.desiredAccuracy = kCLLocationAccuracyBest
manager.requestWhenInUseAuthorization()
manager.delegate = self
manager.startUpdatingLocation()
}
public func getLocation(_ onLocation: ((CLLocationCoordinate2D) -> Void)?) {
self.onLocation = onLocation
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print(#function, locations)
guard let currentCoordinate = manager.location?.coordinate else {return}
onLocation?(currentCoordinate)
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
print(#function, error)
}
}
this code is not calling didUpdateLocation or didFailWithError. can anyone tell me what could be the problem here?
LocationManager().getLocation { coordinate in
print(#function, coordinate)
}
this is how i am calling it.
You need to retain the let manager = CLLocationManager() in your class as a property. Otherwise, it will be deallocated at the end of that function and hence none of its delegate methods will be called at all.
UPDATED
Another issue is the following code where you call getLocation. You need to retain LocationManager() in your client class otherwise the LocationManager will be deallocated at the end of that function.
private let locationManager = LocationManager()
locationManager.getLocation { coordinate in
print(#function, coordinate)
}
I Liked the concept of Protocol Oriented Programming and I am trying to start writing protocols by Protocol Extensions in swift.
I am trying to bring device location using Protocol Extensions.
However I am facing problems on creating that as the following:
import Foundation
import CoreLocation
protocol Locator:CLLocationManagerDelegate {
var locationManager:CLLocationManager!
{ get set }
var locationHandler: ((CLLocation)->())?
{ get set }
func getLocation(completionHandler:#escaping (CLLocation)->())
}
extension Locator {
private var _locationManager:CLLocationManager {
get {return self.locationManager} set {self.locationManager = newValue}
}
private var _locationHandler:((CLLocation)->())? {
get {return self.locationHandler} set {self.locationHandler = newValue}
}
func getLocation(completionHandler:#escaping (CLLocation)->()) {
self.locationManager = CLLocationManager()
self.locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers
let status = CLLocationManager.authorizationStatus()
switch status {
case .notDetermined:
self.locationManager.requestAlwaysAuthorization()
return
case .denied, .restricted:
return
case .authorizedAlways, .authorizedWhenInUse:
self.locationManager.startUpdatingLocation()
#unknown default:
break
}
self.locationHandler = completionHandler
}
func locationManager(_ manager: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
if status == .authorizedWhenInUse || status == .authorizedAlways {
self.locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print("Hey this is a location")
if let currentLocation = locations.last {
self._locationHandler?(currentLocation)
}
}
}
However the completion handler is not working properly.
what is my problem and How can I proceed creating this in Protocols concept.
I am currently trying to get the current coordinates of the user and ultimately store those values into variables.
I have created the following class to define the users current location and set up functions to pull data.
import Foundation
import CoreLocation
class MyCurrentCoordinate: NSObject {
private var currentLocation: CLLocation!
var myLatitude = 0.0
var myLongitude = 0.0
var myAltitude = 0.0
override init() {
super.init()
}
func getLat() {
myLatitude = currentLocation.coordinate.latitude
}
func getLong() {
myLongitude = currentLocation.coordinate.longitude
}
func getAlt() {
myAltitude = currentLocation.altitude
}
}
This does not show any errors. However, when I go to call any function (getLat, getLong, or getAlt) to pull a piece of the users location data, the app crashes due the value being nil. Does anyone have any insight as to why the actual user lat, long, or altitude is not being passed?
I have the location permission and info.plist updated to allow the user to give location tracking permission.
import Foundation
import CoreLocation
import UIKit
public protocol LocalizationHelperDelegate: class {
func didUpdateLocation(_ sender: CLLocation)
}
public class LocalizationHelper: NSObject {
public weak var delegate: LocalizationHelperDelegate?
public static var shared = LocalizationHelper()
private lazy var locationManager: CLLocationManager = {
let locationManager = CLLocationManager()
locationManager.requestAlwaysAuthorization()
locationManager.allowsBackgroundLocationUpdates = true
locationManager.pausesLocationUpdatesAutomatically = false
locationManager.desiredAccuracy = kCLLocationAccuracyBest
return locationManager
}()
private var currentLocation: CLLocationCoordinate2D?
public func startUpdatingLocation() {
locationManager.delegate = self
locationManager.startUpdatingLocation()
}
public func stopUpdatingLocation() {
locationManager.stopUpdatingLocation()
}
public func getCurrentLocation() -> CLLocationCoordinate2D? {
return currentLocation
}
public func getLat() -> Double{
return currentLocation?.latitude ?? 0.0
}
public func getLon() -> Double{
return currentLocation?.longitude ?? 0.0
}
}
extension LocalizationHelper: CLLocationManagerDelegate {
public func locationManager(_: CLLocationManager, didUpdateLocations locations: [CLLocation]){
guard let location = locations.first else { return }
currentLocation = location.coordinate
print("[Update location at - \(Date())] with - lat: \(currentLocation!.latitude), lng: \(currentLocation!.longitude)")
delegate?.didUpdateLocation(location)
}
}
How to use
LocalizationHelper.shared.Start()
...
let lat = LocalizationHelper.shared.getLat()
let lon = LocalizationHelper.shared.getLon()
...
LocalizationHelper.shared.Stop()
You can use CLLocationManager
Add app capability, you can open your info.plist like source code and add:
<key>NSLocationAlwaysAndWhenInUseUsageDescription</key>
<string>App requires allways tracking</string>
<key>NSLocationAlwaysUsageDescription</key>
<string>App requires background tracking</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>App requires tracking when be in use</string>
<key>UIBackgroundModes</key>
<array>
<string>fetch</string>
<string>location</string>
<string>remote-notification</string>
</array>
Ask for authorization like locationManager.requestAlwaysAuthorization() and manage if have the correct access... CLLocationManager.authorizationStatus() == .authorizedAlways
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
var locationManager: CLLocationManager?
override func viewDidLoad() {
super.viewDidLoad()
locationManager = CLLocationManager()
locationManager?.delegate = self
locationManager?.requestAlwaysAuthorization()
if CLLocationManager.authorizationStatus() == .authorizedAlways {
locationManager.allowsBackgroundLocationUpdates = true
locationManager.pausesLocationUpdatesAutomatically = false
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.startUpdatingLocation()
}
if CLLocationManager.authorizationStatus() == .authorizedWhenInUse {
locationManager.allowsBackgroundLocationUpdates = false
locationManager.pausesLocationUpdatesAutomatically = true
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.startUpdatingLocation()
}
}
}
extension ViewController: CLLocationManagerDelegate {
public func locationManager(_: CLLocationManager, didUpdateLocations locations: [CLLocation]){
guard let location = locations.first else { return }
print(location)
}
public func locationManager(_: CLLocationManager, didChangeAuthorization status: CLAuthorizationStatus) {
switch status {
case .notDetermined:
print("Autorization status did change \(status)")
case .authorizedWhenInUse:
print("Autorization status did change \(status)")
case .authorizedAlways:
print("Autorization status did change \(status)")
case .restricted:
print("Autorization status did change \(status)")
case .denied:
print("Autorization status did change \(status)")
#unknown default:
fatalError()
}
}
}
Don't forget to stop it in some place locationManager.stopUpdatingLocation()
I wrote a program that uses LocationManagerDelegate to display coordinates in the debug area whenever the current location changes. Got an error when retrieving coordinates
Can not use instance member 'locationManager' within property initializer; property initializers run before 'self' is available
import UIKit
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate{
var locationManager: CLLocationManager!
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
setUpLocationManager()
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
func setUpLocationManager() {
locationManager = CLLocationManager()
guard let locationManager = locationManager else {return}
locationManager.requestWhenInUseAuthorization()
let status = CLLocationManager.authorizationStatus()
if status == .authorizedWhenInUse {
locationManager.delegate = self
locationManager.distanceFilter = 10
locationManager.startUpdatingLocation()
printLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) ->Optional<Any> {
let location = locations.first
let latitude = location?.coordinate.latitude
let longitude = location?.coordinate.longitude
let latlong = [latitude, longitude]
return latlong
}
let myLocation = locationManager()
func printLocation() {
print("test\(myLocation)")
}
}
test (Function)
is output
let myLocation = locationManager ()
When you change to
let myLocation = locationManager
Your code contains a few mistakes.
The error occurs because you cannot execute the affected line on the top level of the class.
First of all you must not change signatures of delegate methods. This custom delegate method
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) ->Optional<Any> { ...
will never be called.
And apart from that why do you declare the return type as Any? although it's supposed to be [CLLocationCoordinate2D]?
Create the location manager immediately, replace
var locationManager: CLLocationManager!
with
let locationManager = CLLocationManager()
In setUpLocationManager() delete the lines
locationManager = CLLocationManager()
guard let locationManager = locationManager else {return} // this line is completely pointless anyway
printLocation()
The delegate method didUpdateLocations is called periodically and asynchronously. Print the result inside the method
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.first else { return }
let latitude = location.coordinate.latitude
let longitude = location.coordinate.longitude
let latlong = [latitude, longitude]
print("test", latlong)
}
Delete
let myLocation = locationManager()
func printLocation() {
print("test\(myLocation)")
}
I am trying to use the below LocationSingleton Class from this blog in my project. I like the simplicity of its usage.
You start updating location by simply calling:
LocationSingleton.sharedInstance.startUpdatingLocation()
Get the last location by simply calling:
LocationSingleton.sharedInstance.lastLocation
My intention is to start location services, get the last location so that I can then fetch users from Firebase using the location returned.
The issue is that if I call lastLocation straight after startUpdatingLocation it returns nil.
After some debugging I've found the reason is because location services are slow to start on the device and therefore when lastLocation is called the devices hasn't acquired the location yet. I would like to execute the next command as soon as the lastLocation has been recorded. How can I achieve that?
I would like to understand how the Protocol is being used?
import UIKit
import CoreLocation
protocol LocationServiceDelegate {
func locationDidUpdateToLocation(currentLocation: CLLocation)
func locationUpdateDidFailWithError(error: NSError)
}
class LocationSingleton: NSObject,CLLocationManagerDelegate {
var locationManager: CLLocationManager?
var lastLocation: CLLocation?
var delegate: LocationServiceDelegate?
static let sharedInstance:LocationSingleton = {
let instance = LocationSingleton()
return instance
}()
override init() {
super.init()
self.locationManager = CLLocationManager()
guard let locationManagers=self.locationManager else {
return
}
if CLLocationManager.authorizationStatus() == .notDetermined {
//locationManagers.requestAlwaysAuthorization()
locationManagers.requestWhenInUseAuthorization()
}
if #available(iOS 9.0, *) {
// locationManagers.allowsBackgroundLocationUpdates = true
} else {
// Fallback on earlier versions
}
locationManagers.desiredAccuracy = kCLLocationAccuracyBest
locationManagers.pausesLocationUpdatesAutomatically = false
locationManagers.distanceFilter = 0.1
locationManagers.delegate = self
}
func locationManager(_ manager: CLLocationManager, didFailWithError error: Error) {
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
guard let location = locations.last else {
return
}
self.lastLocation = location
updateLocation(currentLocation: location)
}
#nonobjc func locationManager(manager: CLLocationManager!, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
switch status {
case .notDetermined:
locationManager?.requestWhenInUseAuthorization()
break
case .authorizedWhenInUse:
locationManager?.startUpdatingLocation()
break
case .authorizedAlways:
locationManager?.startUpdatingLocation()
break
case .restricted:
// restricted by e.g. parental controls. User can't enable Location Services
break
case .denied:
// user denied your app access to Location Services, but can grant access from Settings.app
break
default:
break
}
}
// Private function
private func updateLocation(currentLocation: CLLocation){
guard let delegate = self.delegate else {
return
}
delegate.locationDidUpdateToLocation(currentLocation: currentLocation)
}
private func updateLocationDidFailWithError(error: NSError) {
guard let delegate = self.delegate else {
return
}
delegate.locationUpdateDidFailWithError(error: error)
}
func startUpdatingLocation() {
print("Starting Location Updates")
self.locationManager?.startUpdatingLocation()
// self.locationManager?.startMonitoringSignificantLocationChanges()
}
func stopUpdatingLocation() {
print("Stop Location Updates")
self.locationManager?.stopUpdatingLocation()
}
func startMonitoringSignificantLocationChanges() {
self.locationManager?.startMonitoringSignificantLocationChanges()
}
}
The location manager works asynchronously and provides delegate methods to get the result.
In your class adopt LocationServiceDelegate, implement the delegate methods and set the delegate for example in viewDidLoad
func locationDidUpdateToLocation(currentLocation: CLLocation)
{
print(LocationSingleton.sharedInstance.lastLocation)
}
func locationUpdateDidFailWithError(error: NSError)
{
print(error)
}
func viewDidLoad()
super viewDidLoad()
let locationSingleton = LocationSingleton.sharedInstance
locationSingleton.delegate = self
locationSingleton.startUpdatingLocation()
}
When a location is detected, one of the delegate methods is called