I am working on some internal location tracking, just to see how accurate it can get (not very). The app is never going on the app store
Can I just check I have done everything to enable background iBeacons updates (didRangeBeacons) to happen, it does seem to work but die 20 mins later. This could be useful to others as there seemed mixed info out there.
I am using iOS 9
Enable location updates in Capabilities
On each region enable region.notifyEntryStateOnDisplay = true
On Location Manager enable locationManager.allowsBackgroundLocationUpdates
locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers (set this to save battery
Implement didUpdateLocations delegate method but you don't need to do anything here
I also implemented didUpdateToLocation delegate method just for belts and braces
Make sure you have the pList entries for Location Manager (NSLocationAlwaysUsageDescription, NSLocationWhenInUseDescription)
Related
Trying to get my app to use less power, it's tracking location always in the background but I'd like for it automatically pause so I can turn on region watching and use that to resume precise location monitoring once the user moves around a bit.
I've had the app on for half an hour now and the location service is not pausing. I think this has been the case since Apple changed location stuff in iOS 13? I'm not really sure. All the documentation I can find online seems extremely outdated.
Any advice is greatly appreciated, relevant code follows:
init() {
locationManager = CLLocationManager()
locationManager.delegate = self
locationManager.desiredAccuracy = kCLLocationAccuracyBest
locationManager.distanceFilter = 10
locationManager.activityType = .fitness
locationManager.requestAlwaysAuthorization()
locationManager.allowsBackgroundLocationUpdates = true
locationManager.pausesLocationUpdatesAutomatically = true
locationManager.showsBackgroundLocationIndicator = true
locationManager.startUpdatingLocation()
}
func locationManagerDidPauseLocationUpdates(_ manager: CLLocationManager) {
delegate?.paused(tracker: self)
print("MT | LOCATION SERVICES PAUSED!") <---- NEVER GETTING CALLED (been running for 40 minutes now, no location updates, still going though?)
// if not already, start region monitoring
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
// Collect data
for location in locations {
print("MT | New Location: \(location)")
}
}
I wouldn't rely on connecting to Xcode. Xcode is generally greedy. It doesn't want you to stop your debugging. So it never puts the app in a suspended state.
The callback of locationManagerDidPauseLocationUpdates is somewhat identical to your app being suspended which Xcode prevents.
The way I would test this is to use os.log. Then log the outputs to your Mac's console app. See here.
Just make sure the app is not launched from you running from Xcode. I'd rather disconnect your device from Xcode, kill the app. Disconnect your device from Xcode. Then just tap on the app icon again. That way Xcode cannot intervene.
The issue is caused by your desired accuracy.
You are setting the accuracy to the best, which will make your application run continuously, so it will never pause in any iOS versions.
Furthermore, in a practical test whether it is pausing or not, change the accuracy to kCLLocationAccuracyHundredMeters. It will definitely pause. You can change the filter accuracy as you need for the next update.
Do you think maybe your activityType is preventing the location services to pause?
activityType
The location manager uses the information in this property as a cue to determine when location updates may be automatically paused. Pausing updates gives the system the opportunity to save power in situations where the user's location is not likely to be changing.
.fitness
This activity might cause location updates to be paused only when the user does not move a significant distance over a period of time.
I don't know what your particular use case is but, have you considered using the following function for background location tracking?
startMonitoringSignificantLocationChanges()
You may also try a mix of both, turning on significant location changes for day to day use and allowsBackgroundLocation when doing something like tracking a run, etc.
I think it is quite clear from the docs that this the pause functionality does not work like that. First of all, there is no guarantee that the GPS hardware will pause at all, it depends on the type of activity as well as other activities in the system. It is up to iOS to decide when and if to pause location updates, the property is just a hint.
More important, your use case would not work since if it gets paused, the user would have to interact with your app manually to resume updates.
Apple mentions your case specifically and recommends reducing the accuracy of location updates so it is only using cell tower triangulation instead of GPS (see docs above).
So, instead of using pausesLocationUpdatesAutomatically = true, you could do desiredAccuracy = kCLLocationAccuracyThreeKilometers.
To quote Apple,
[...] consider disabling this property and changing location accuracy to kCLLocationAccuracyThreeKilometers when your app moves to the background. Doing so allows you to continue receiving location updates in a power-friendly manner
Doesn't this cover your use case?
I've created a simple app which tracks user location and creates local notification for every time location is updated.
I enabled the background modes below,
let locationManager = CLLocationManager()
open override func viewDidLoad() {
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = 10
locationManager.allowsBackgroundLocationUpdates = true
locationManager.startUpdatingLocation()
}
open func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let notification = UILocalNotification()
notification.alertBody = "location updated"
notification.fireDate = Date()
UIApplication.shared.scheduleLocalNotification(notification)
}
I set string for NSLocationAlwaysUsageDescription and ask for permission. User grant permission for always usage when the app loaded first time.
It's working well when app is in the foreground, when it goes background still working at least in 5-40 minutes time range which is changeable
by battery or other opened apps.
The problem is why it stops working, Isn't it expected to be keep working?
I've never seen a time limit in Apple docs.
Switch to significant location updates when the app moves to background. iOS will unload the app if it keep alive in the background indefinitely.
locationManager.pausesLocationUpdatesAutomatically = false
Reduce Accuracy
Set the desiredAccuracy property of the location manager object
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
You can use one of the CLLocationAccuracy constants
IMPORTANT
By default, standard location updates on iOS devices run with an accuracy level of best. Change these settings to match
your app’s requirements. Otherwise, your app will unnecessarily waste
energy.
Auto-Pause
Set the pausesLocationUpdatesAutomatically property of the location manager object to true
self.locationManager.pausesLocationUpdatesAutomatically = true
IMPORTANT
For apps that have in-use authorization, a pause to location updates
ends access to location changes until the app is launched again and
able to restart those updates. If you do not wish location updates to
stop entirely, consider disabling this property and changing location
accuracy to kCLLocationAccuracyThreeKilometers when your app moves
to the background. Doing so allows you to continue receiving location
updates in a power-friendly manner.
Allow background updates
Set the allowsBackgroundLocationUpdates property of the location manager object to true
self.locationManager.allowsBackgroundLocationUpdates = true
Apps that want to receive location updates when suspended must include
the UIBackgroundModes key (with the location value) in their app’s
Info.plist file and set the value of this property to true. The
presence of the UIBackgroundModes key with the location value is
required for background updates
Specify an Activity Type
Set the activityType property to let Core Location know what type of location activity your app is performing at a given time
self.locationManager.activityType = .automotiveNavigation
You can use one of the CLActivityType cases
Defer Location Update
On supported devices with GPS hardware, you can let the location
manager defer the delivery of location updates when your app is in the
background. For example, a fitness app that tracks the user’s location
on a hiking trail can defer updates until the user has moved a certain
distance or a certain period of time has elapsed.
Energy Efficiency Guide for iOS Apps - Location Best Practices
GettingLocationWhenSuspended
After searching for references (talking about any limitation), I assume that Apple Core Location Best Practices video session could be useful! at 06:53 talking about standard location in the background:
furthermore, Core Location won't take any action to ensure your app
continues to run, so if you have background run for some reason and
you decide to start a location session you might get some updates, but
you might also get suspended before you receive all information that
you hope to receive...
Actually, I faced this issue before, -as a workaround- the core location was used to keep tracking the location of the user to do unrelated functionality to its location -which is uploading files-, but this workaround didn't work since iOS 9 has been released; I even posted a question referring to this issue.
However, it seems your case is not identical to what I faced, if you are aiming to:
... creates local notification for every time location is updated.
then you might need to follow the approach of integrating with User Notification Framework - UNLocationNotificationTrigger:
The geographic location that the user must reach to enable the
delivery of a local notification.
It is also mentioned in the video session (08:59).
Probably, this is could be not what are you looking for, but since we have no guarantee that the background execution will continue running, you might -somehow- find a way to integrate it in your app to achieve the desired functionality.
Update for iOS 11:
You might need to check this answer for the proper way to request the location access.
By the sound of it the app is being killed due to memory constraints.
It should however be re-launched when a new location becomes available, as described here: https://developer.apple.com/documentation/uikit/uiapplicationlaunchoptionskey/1623101-location
You should see application(_:didFinishLaunchingWithOptions:) being called, and the 'location' key should be present in the launch options. You'll can then re-create whatever is consuming the locations and continue recording.
If it's not being re-launched it could be too memory hungry. Check the memory consumption of the app and see if applicationDidReceiveMemoryWarning(_:) is being called.
I assume you haven't implement background task. You can read here.
In the above link under section "Implementing Long-Running Tasks" point no. 3 is your situation, so it's valid you can use background location update in your project and for same you need to implement a background task too.
There are three way to track user location(as per above link under section "Tracking the User’s Location" ) :-
Foreground-only location services (which works in your case)
The significant-change location service (Recommended), but I think it is not usable in your case as you want to update user location per 10 meter and it works for ~500 meters, for more please see here
Background location services (I think you are trying for this) and solution is to add a background task.
Below is example of background task and you can modify as per your requirement, it works for me since last 2 hours and my app still update location in background.
.
In your AppDelegate class please update below function and then run your app in background.
func applicationDidEnterBackground(_ application: UIApplication) {
application.beginBackgroundTask(withName: "") {}
}
And below is my ViewController class
import UIKit
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
let locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self;
locationManager.requestAlwaysAuthorization()
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.allowsBackgroundLocationUpdates = true
locationManager.distanceFilter = kCLDistanceFilterNone
Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { (timer) in
self.locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print("didUpdateLocations \(Date())")
self.locationManager.stopUpdatingLocation()
}
}
I ran into this where a QT app would stop getting location events in the background after an hour or two.
In the App Delegate when the app would go into the background I would stop the CLLocationManager, decrease the Accuracy from kCLLocationAccuracyBest to kCLLocationAccuracyNearestTenMeters AND increase the distance filter from None to 50 meters and it would then track for 24+ hours.
I've created a simple app which tracks user location and creates local notification for every time location is updated.
I enabled the background modes below,
let locationManager = CLLocationManager()
open override func viewDidLoad() {
locationManager.delegate = self;
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.distanceFilter = 10
locationManager.allowsBackgroundLocationUpdates = true
locationManager.startUpdatingLocation()
}
open func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
let notification = UILocalNotification()
notification.alertBody = "location updated"
notification.fireDate = Date()
UIApplication.shared.scheduleLocalNotification(notification)
}
I set string for NSLocationAlwaysUsageDescription and ask for permission. User grant permission for always usage when the app loaded first time.
It's working well when app is in the foreground, when it goes background still working at least in 5-40 minutes time range which is changeable
by battery or other opened apps.
The problem is why it stops working, Isn't it expected to be keep working?
I've never seen a time limit in Apple docs.
Switch to significant location updates when the app moves to background. iOS will unload the app if it keep alive in the background indefinitely.
locationManager.pausesLocationUpdatesAutomatically = false
Reduce Accuracy
Set the desiredAccuracy property of the location manager object
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation
You can use one of the CLLocationAccuracy constants
IMPORTANT
By default, standard location updates on iOS devices run with an accuracy level of best. Change these settings to match
your app’s requirements. Otherwise, your app will unnecessarily waste
energy.
Auto-Pause
Set the pausesLocationUpdatesAutomatically property of the location manager object to true
self.locationManager.pausesLocationUpdatesAutomatically = true
IMPORTANT
For apps that have in-use authorization, a pause to location updates
ends access to location changes until the app is launched again and
able to restart those updates. If you do not wish location updates to
stop entirely, consider disabling this property and changing location
accuracy to kCLLocationAccuracyThreeKilometers when your app moves
to the background. Doing so allows you to continue receiving location
updates in a power-friendly manner.
Allow background updates
Set the allowsBackgroundLocationUpdates property of the location manager object to true
self.locationManager.allowsBackgroundLocationUpdates = true
Apps that want to receive location updates when suspended must include
the UIBackgroundModes key (with the location value) in their app’s
Info.plist file and set the value of this property to true. The
presence of the UIBackgroundModes key with the location value is
required for background updates
Specify an Activity Type
Set the activityType property to let Core Location know what type of location activity your app is performing at a given time
self.locationManager.activityType = .automotiveNavigation
You can use one of the CLActivityType cases
Defer Location Update
On supported devices with GPS hardware, you can let the location
manager defer the delivery of location updates when your app is in the
background. For example, a fitness app that tracks the user’s location
on a hiking trail can defer updates until the user has moved a certain
distance or a certain period of time has elapsed.
Energy Efficiency Guide for iOS Apps - Location Best Practices
GettingLocationWhenSuspended
After searching for references (talking about any limitation), I assume that Apple Core Location Best Practices video session could be useful! at 06:53 talking about standard location in the background:
furthermore, Core Location won't take any action to ensure your app
continues to run, so if you have background run for some reason and
you decide to start a location session you might get some updates, but
you might also get suspended before you receive all information that
you hope to receive...
Actually, I faced this issue before, -as a workaround- the core location was used to keep tracking the location of the user to do unrelated functionality to its location -which is uploading files-, but this workaround didn't work since iOS 9 has been released; I even posted a question referring to this issue.
However, it seems your case is not identical to what I faced, if you are aiming to:
... creates local notification for every time location is updated.
then you might need to follow the approach of integrating with User Notification Framework - UNLocationNotificationTrigger:
The geographic location that the user must reach to enable the
delivery of a local notification.
It is also mentioned in the video session (08:59).
Probably, this is could be not what are you looking for, but since we have no guarantee that the background execution will continue running, you might -somehow- find a way to integrate it in your app to achieve the desired functionality.
Update for iOS 11:
You might need to check this answer for the proper way to request the location access.
By the sound of it the app is being killed due to memory constraints.
It should however be re-launched when a new location becomes available, as described here: https://developer.apple.com/documentation/uikit/uiapplicationlaunchoptionskey/1623101-location
You should see application(_:didFinishLaunchingWithOptions:) being called, and the 'location' key should be present in the launch options. You'll can then re-create whatever is consuming the locations and continue recording.
If it's not being re-launched it could be too memory hungry. Check the memory consumption of the app and see if applicationDidReceiveMemoryWarning(_:) is being called.
I assume you haven't implement background task. You can read here.
In the above link under section "Implementing Long-Running Tasks" point no. 3 is your situation, so it's valid you can use background location update in your project and for same you need to implement a background task too.
There are three way to track user location(as per above link under section "Tracking the User’s Location" ) :-
Foreground-only location services (which works in your case)
The significant-change location service (Recommended), but I think it is not usable in your case as you want to update user location per 10 meter and it works for ~500 meters, for more please see here
Background location services (I think you are trying for this) and solution is to add a background task.
Below is example of background task and you can modify as per your requirement, it works for me since last 2 hours and my app still update location in background.
.
In your AppDelegate class please update below function and then run your app in background.
func applicationDidEnterBackground(_ application: UIApplication) {
application.beginBackgroundTask(withName: "") {}
}
And below is my ViewController class
import UIKit
import CoreLocation
class ViewController: UIViewController, CLLocationManagerDelegate {
let locationManager = CLLocationManager()
override func viewDidLoad() {
super.viewDidLoad()
locationManager.delegate = self;
locationManager.requestAlwaysAuthorization()
locationManager.desiredAccuracy = kCLLocationAccuracyBest;
locationManager.allowsBackgroundLocationUpdates = true
locationManager.distanceFilter = kCLDistanceFilterNone
Timer.scheduledTimer(withTimeInterval: 1.0, repeats: true) { (timer) in
self.locationManager.startUpdatingLocation()
}
}
func locationManager(_ manager: CLLocationManager, didUpdateLocations locations: [CLLocation]) {
print("didUpdateLocations \(Date())")
self.locationManager.stopUpdatingLocation()
}
}
I ran into this where a QT app would stop getting location events in the background after an hour or two.
In the App Delegate when the app would go into the background I would stop the CLLocationManager, decrease the Accuracy from kCLLocationAccuracyBest to kCLLocationAccuracyNearestTenMeters AND increase the distance filter from None to 50 meters and it would then track for 24+ hours.
I am writing (in Swift) an iOS 9 app that needs location updates including in background mode. The problem is that I only get location updates in foreground. I think I have done everything correctly:
In info.plist:
Specified a value for NSLocationAlwaysUsageDescription.
Specified a value for NSLocationUsageDescription.
Specified a value for NSLocationWhenInUseUsageDescription.
Included "location" in UIBackgroundModes.
Included "gps" and "location-services" in UIRequiredDeviceCapabilities
Started the location manager as follows:
let locationManager = CLLocationManager()
locationManager.desiredAccuracy =
kCLLocationAccuracyHundredMeters
locationManager.distanceFilter = 250.0
locationManager.allowsBackgroundLocationUpdates = true
locationManager.startUpdatingLocation()
I have also verified that
locationManager.pausesLocationUpdatesAutomatically is false.
I get no location updates while the app is not in the foreground. The only time I do get location updates is if I bring the app to foreground, and even then, not all the time.
Any idea what's going wrong? Or my expectations incorrect?
How are you sending the app to the background? If you swipe to kill then your app won't automatically restart to receive the location events. I don't see it in your code, did you call requestAlwaysAuthorization? You might also want to implement LocationManager:didFailWithError just to see if that gives you any ideas.
I am trying to make an app to track the user GPS all the time, this app is a kind of car GPS tracker to get the location of driver all the time and send it to server.
I have tried to add "location updates" to the "background modes" but the app will automatically suspends after 10 mins when going into background.
Is there a way to make this app run all the time and get the GPS location?
You have two options here:
1) Regular location tracking. This type of tracking works with kCLAuthorizationStatusAuthorizedWhenInUse and kCLAuthorizationStatusAuthorizedAlways authorizations. When CLLocationManager started tracking location once it will receive location updates in delegate method locationManager:didUpdateLocations:. App can go to suspended state, but when location manager receive new location app goes to background state and handles new location in delegate method. How to setup location manager:
- (void)viewDidLoad {
[super viewDidLoad];
self.locationManager = [[CLLocationManager alloc] init];
// Setup location tracker accuracy
self.locationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
// Distance filter
self.locationManager.distanceFilter = 50.f;
// Assign location tracker delegate
self.locationManager.delegate = self;
// This setup pauses location manager if location wasn't changed
[self.locationManager setPausesLocationUpdatesAutomatically:YES];
// For iOS9 we have to call this method if we want to receive location updates in background mode
if([self.locationManager respondsToSelector:#selector(allowsBackgroundLocationUpdates)]){
[self.locationManager setAllowsBackgroundLocationUpdates:YES];
}
[self.locationManager startUpdatingLocation];
}
2) Signification location changes tracking. This type of tracking works only with kCLAuthorizationStatusAuthorizedAlways authorization. It receives new location only each 500 meters, so distance filter and desiredAccuracy don't work here. App can go to suspended state, and even can be terminated by system, but when location updates app goes to background state and receives location in delegate method locationManager:didUpdateLocations:.If app was terminated by system, it will be relaunched in background with UIApplicationLaunchOptionsLocationKey key in launch options in didFinishLaunchingWithOptions app delegate method. How to setup this type on tracking:
- (void)viewDidLoad {
[super viewDidLoad];
self.locationManager = [[CLLocationManager alloc] init];
// Assign location tracker delegate
self.locationManager.delegate = self;
// For iOS9 we have to call this method if we want to receive location updates in background mode
if([self.locationManager respondsToSelector:#selector(allowsBackgroundLocationUpdates)]){
[self.locationManager setAllowsBackgroundLocationUpdates:YES];
}
[self.locationManager startMonitoringSignificantLocationChanges];
}
You should notice that both of these methods does not guarantee that your application does not go to suspended state.
Also, if app was terminated by user (for example from app switcher by swipe) location tracking in background will not work.
UPDATE (corresponding to comments)
Here is my code examples that work for me:
For Regular tracking. Run the example, provide access to user location, tap Start button to start location updates. To test locations in simulator choose in simulator menu Debug > Location > Freeway Drive. Now you can push app to background by home button (Command+Shift+H). Leave simulator for more than 10 minutes, and all this time app will receive locations. When you return to app you will see red pins on the map.
For Significant changes. Run the app and test by the same way as for previous example.
Monitoring Significant changes can be started only by method [self.locationManager startMonitoringSignificantLocationChanges];
UPDATE (iOS 11)
Changes to location tracking in iOS 11
iOS 11 also makes some major changes to existing APIs. One of the affected areas is location tracking. If your app only uses location while the app is in the foreground, as most apps do, you might not have to change anything at all; however, if it’s one of those apps that continuously track user’s location throughout the day, you should probably book some time this summer for making some changes in how you do the tracking and testing possible usage scenarios.
follow this link: https://mackuba.eu/2017/07/13/changes-to-location-tracking-in-ios-11/
I am sure it is useful for the author because the question was asked in Feb 2016 and I am giving an answer in June 2019. This answer maybe is useful for other users.
Recently, I was working with the same requirement. After 2-3 week hard work, I did it. For other users, I create a helper class for it. Which is available in GitHub.
Please use HSLocationManager for your requirement. I have achieved the same requirements in one of my project
Location manager that allows getting background location updates every
n seconds with desired location accuracy.
Advantage:
OS will never kill our app if the location manager is currently
running.
Give periodically location update when it required(range is between 2 -
170 seconds (limited by max allowed background task time))
Customizable location accuracy and time period.
Low memory consumption(Singleton class)
In reply to comment 1 in the solution (I can't comment anywhere yet): you didn't seem to solve the problem as your app gets suspended and doesn't update the location any more after 10 minutes.
I had the same issue: I had set setAllowsBackgroundLocationUpdates to YES, and I had the NSLocationAlwaysUsageDescription key in my Info.plist, but my App also used to stop tracking location after 10 minutes.
I solved it by adding both NSLocationAlwaysUsageDescription and NSLocationWhenInUseUsageDescription to the Info.plist file so it looks like this:
<key>NSLocationAlwaysUsageDescription</key>
<string>This app needs to use your location</string>
<key>NSLocationWhenInUseUsageDescription</key>
<string>This app needs to use your location</string>
set it.it take power of battery but your application run in Background.OS does not Suspend your App
[self.locationManager setPausesLocationUpdatesAutomatically:NO];