I am trying to get the user's location at the time of a button press, however I am having trouble setting up the location code. I've been looking between various answers on Stackoverflow but I can't get anything to work for me.
class MyViewController: UIViewController, CLLocationManagerDelegate {
var locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyHundredMeters
locationManager.requestWhenInUseAuthorization()
locationManager.startUpdatingLocation()
}
func locationManager(manager: CLLocationManager, didChangeAuthorizationStatus status: CLAuthorizationStatus) {
if status == .AuthorizedAlways || status == .AuthorizedWhenInUse {
let latitude = self.locationManager.location?.coordinate.latitude
let longitude = self.locationManager.location?.coordinate.longitude
print("coordinates:")
print(latitude)
print(longitude)
}
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let locationValue : CLLocationCoordinate2D = manager.location!.coordinate
print("locations = \(locationValue.latitude) \(locationValue.longitude)")
}
However I just get nils from the prints in didChangeAuthorizationStatus and nothing ever prints from didUpdateLocations. Im also really confused about where to put startUpdatingLocation(). Some answers place it directly in viewDidLoad as I have here, others place it in didChangeAuthorizationStatus, and I saw another place it inside an if CLLocationManager.locationServicesEnabled() in didLoad. What is the correct way to do this? And also what have I done wrong that I'm not getting any values printing? I'm running on the emulator, have location turned on and allowed permissions in the pop-up, and have the emulator set to a lat/long custom location, and I have added the values in pList.
edit: even tried copy/pasting the code from this to get user's location only once but it returns (kCLErrorDomain error 0.). I added a 'requestWhenInUseAuthorization()` to their code but it still fails.
get nils from the prints in didChangeAuthorizationStatus
Because we don't have any locations yet. That's the wrong place to ask for that information. All that happened is that we are now authorized.
nothing ever prints from didUpdateLocations
Because you're running on the simulator, perhaps. Try running on a device.
And, if your goal is just to get the location and stop, don't use startUpdatingLocation; call requestLocation. That's what it's for.
Related
I have the following code
class ViewController: UIViewController, UITableViewDataSource, UITableViewDelegate, CLLocationManagerDelegate {
var locationManager = CLLocationManager()
var coordinates: String?
override func viewDidLoad() {
super.viewDidLoad()
self.locationManager.requestAlwaysAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
//updates the user's location as the user moves
let location: CLLocation = locations[0] as CLLocation
coordinates = "\(location.coordinate.latitude),\(location.coordinate.longitude)"
print(coordinates!)
}
When I run this on the simulator, the program works fine but it doesn't print the coordinates. When I run it on my iPhone, it prints the coordinates. Is there something in the Xcode settings I need to change to fix this? Also, when I try to use the "coordinates" variable in another function, I get an error saying the compiler is finding nil even though I assigned it a value in the locationManager function, so I'm guessing the two problems are connected. Thanks in advance
You can simulate location on the simulator using "Simulate location" button when running your app:
You can select one of the existing locations or you can create a GPX file (for example not a static single point but a route that will simulate constant changing of location). I would recommend you using https://mapstogpx.com/ to create GPX files.
I am trying to simply get the user's current device location and store it in a global variable called userLoc. I have this code to call didUpdateLocation:
self.locationManager.requestLocation()
print("aaa ", self.userLoc)
and this to set the userLoc to the current location:
func locationManager(_ manager: CLLocationManager,
didUpdateLocations locations: [CLLocation]) {
if let location = locations.last {
self.userLoc = location
}
}
userLoc is defined like this:
var userLoc: CLLocation?
but when I run the app and try to print userLoc, it ALWAYS prints:
aaa nil
The Privacy - Location When In Use Usage Description is set in the Info.plist. I honestly dont know what else to try. I've been banging my head against the wall for a while trying to fix this. Any help you could give would be very much appreciate. Thank you.
This is what I do to get user location within my view controller class. I think you are missing locationManager.startUpdatingLocation():
var currentLocation: CLLocationCoordinate2D!
var locationManager: CLLocationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.startUpdatingLocation()
currentLocation = locationManager.location!.coordinate
Im creating this app, and it needs to get the users location - its all working properly, the thing is, that the time from accepting the use of location services, to getting the actual location takes like 5 seconds - is this normal?
I've used other apps, where it goes much faster..
Here's what my code looks like:
override func viewDidLoad() {
super.viewDidLoad()
// Ask for Location-Authorisation from the User.
self.locationManager.requestWhenInUseAuthorization()
if CLLocationManager.locationServicesEnabled() {
locationManager.delegate = self
locationManager.requestLocation()
}
mapView.delegate = self
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let locValue: CLLocationCoordinate2D = manager.location!.coordinate
let initialLocation = CLLocation(latitude: locValue.latitude, longitude: locValue.longitude)
self.centerMapOnLocation(initialLocation)
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError) {
print("could not get location")
}
But the time from the application gets the location to put into the centerMapOnLocation-function, seems just to be quite long. What is to be expected, when getting a users location? I'm testing on a wifi connection, so I know its not because the internet is slow, or its a bad connection...
Anyone have an idea? :)
Best regards!
Try setting the accuracy and use locationManager.startUpdatingLocation(). I do that, and get answer within a second (on the device).
From the documentation of requestLocation():
This method returns immediately. Calling it causes the location manager to obtain a location fix (which may take several seconds) and call the delegate’s locationManager(_:didUpdateLocations:) method with the result.
Source
So basically, everything is fine with your code, it's just how the framework is built.
When initializing your location manager, add startUpdatingLocation():
let manager = CLLocationManager()
manager.delegate = self
manager.requestWhenInUseAuthorization()
manager.requestLocation()
manager.startUpdatingLocation()
Without startUpdatingLocation() geo-location takes about 5 seconds, with it, the request executes nearly immediately.
If you don't want to delay the app's launch for the location manager, consider deploying two location managers (in the app delegate), tasking one with generating a location quickly and the other with generating a location accurately:
fastLoc.delegate = self
fastLoc.desiredAccuracy = kCLLocationAccuracyThreeKilometers
fastLoc.requestWhenInUseAuthorization()
fastLoc.startUpdatingLocation()
bestLoc.delegate = self
bestLoc.desiredAccuracy = kCLLocationAccuracyBest
bestLoc.requestWhenInUseAuthorization()
bestLoc.requestLocation()
The combination of 3 km accuracy with startUpdatingLocation() should return a location almost instantly, almost always before the root view controller is even ready to go. bestLoc manager is likely to return a location well after the user has launched the app but it will be very accurate.
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
switch manager {
case fastLoc:
fastLoc.stopUpdatingLocation()
deviceLocation = locations.last! // set property with fast loc
case bestLoc:
deviceLocation = locations.last! // overwrite property with best loc
default:
break
}
}
Alright, so I have a tableview that, when the view is loaded, it's populated with Parse objects that have geopoints within a set range of user's current location. This works here:
let query: PFQuery = PFQuery(className: "Events")
query.whereKey("location", nearGeoPoint: myGeoPoint, withinMiles: range)
query.findObjectsInBackgroundWithBlock { (objects: [PFObject]?, error) in
if error == nil {
print(objects)
for object in objects! {
self.names.append(object["Name"] as! String)
self.descriptions.append(object["description"] as! String)
}
self.tableView.reloadData()
} else {
print(error)
}
}
}
The issue with this is I need to either have this table reloadData constantly OR just whenever the user's location changes which, I predict, will happen pretty frequently. Because it needs to display the items that are within range, I can't have the user drive somewhere and the table still display the items from the last location.
For other parts of the app I have just have the table refresh when a certain button is clicked, however I need to know how to properly update this table ALWAYS or whenever the user's location changes. I have attempted to use a timer set to a fraction of a second, but that caused issues and didn't seem to be the the correct way.
How can I do this? Regarding always updating the table, I have tried
override func viewDidAppear(animated: Bool) {
self.tableView.reloadData()
}
But that does nothing. Looked at loadObjects() also, but had errors. What is the best way to achieve this?
EDITS:
if (CLLocationManager.locationServicesEnabled())
{
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.requestAlwaysAuthorization()
//locationManager.startUpdatingLocation() //so not always updating
locationManager.startMonitoringSignificantLocationChanges()
}
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
// locations contains an array of recent locations, but this app only cares about the most recent
// which is also "manager.location"
myLoc = PFGeoPoint(location: manager.location)
print("significant change - \(myLoc)")
tableView.reloadData()
}
func locationManager(manager: CLLocationManager, didFailWithError error: NSError!) {
print("failed")
}
Set the distanceFilter property to your location manager.
locationManager.distanceFilter = 50
Now it will only update the user's location if it has changed by 50 or more meters.
So there is the new requestLocation() method on iOS9. I am trying to use it to get only one location update but it hits the didUpdateLocations multiple times.
Isn't this suppose to call it only once ? i have set distanceFilter to 1000.0, so it is pretty broad to help return quickly. Any ideas ?
even if i call the stopUpdatingLocation() inside the delegate method, i still get three hits of the delegate.
Note: same behavior occurs when i use StartUpdatingLocation instead, i want only a single return as i want to obtain the user's current country, so feed the location to reversegeocoder
thanks in advance
Here is the code:
func getLocationOneTime(accuracy: Double){
print("Acquiring location one time - accuracy requested:\(accuracy)")
locationManager.distanceFilter = accuracy
locationManager.desiredAccuracy = accuracy
// Start gpsOneTimeTimeout timer
gpsTimeoutTimer = NSTimer.scheduledTimerWithTimeInterval(gpsOneTimeTimeout, target: self, selector: #selector(self.reportTimeout), userInfo: nil, repeats: false)
locationManager.requestLocation()
}
Usually for this kind of problem I just use an if statement to prevent the delegate function changing anything after the first call
in this case if you are just looking for the location I would do:
let locationManager = CLLocationManager()
var userLocation: CLLocation!
func locationManager(manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
if userLocation == nil {
if let location = locations.first {
userLocation = location
self.locationManager.stopUpdatingLocation()
}
}
}
Edit: I had a look at the apple documentation for this and you are doing things right, I doubt you'll be able to prevent it through any reasonable means sadly.