Is it possible to update location when application is in suspended/terminate state.
i want to update location every 500 meters when app is in suspended/terminate state.
thanks in advance.
When terminated the only real way to get updates is to use Region Monitoring but you will only get major updates so I doubt it will work for 500 meters.
From the documentation:
If your app is terminated either by a user or by the system, the
system doesn't automatically restart your app when new location
updates arrive. A user must explicitly relaunch your app before the
delivery of location updates resumes. The only way to have your app
relaunched automatically is to use region monitoring or
significant-change location service. However, when a user disables the
Background App Refresh setting either globally or specifically for
your app, the system doesn't relaunch your app for any location
events, including significant change or region monitoring events.
Further, while Background App Refresh is off your app won't receive
significant change or region monitoring events even when it's in the
foreground.
There are good reasons for this. Firstly people don't want apps that 'snoop' on them all the time and even if there is a good reason imagine having 10 apps doing this constantly. It's going to start causing you performance and battery life issues.
EDIT
There appears to be some confusion by a lot of people over this issue so I will attempt to clear things up a bit.
Your app is NOT supposed to be continually tracking location while terminated (or suspended really). You are just not allowed to do this both for privacy reasons and so that you don't drain the battery excessively.
While your app is in the foreground you can use location services via startUpdatingLocation to monitor the device location. Assuming the app has been granted permission this will use all available hardware (GPS, WiFi, Cellular).
Now from the documentation itself:
If you start this service and your app is suspended, the system stops
the delivery of events until your app starts running again (either in
the foreground or background). If your app is terminated, the delivery
of new location events stops altogether. Therefore, if your app needs
to receive location events while in the background, it must include
the UIBackgroundModes key (with the location value) in its Info.plist
file.
So once suspended and terminated your options are really to monitor regions and to monitor for significant location changes. Neither of these are particularly accurate or frequent. One reason for this is that they only use low power methods to get the position (WiFi and Cellular) they don't use the GPS.
So no accurate and/or frequent location tracking while an app is suspended or terminated. This just has to be accepted and you need to design your apps accordingly.
let locationManager = CLLocationManager()
locationManager.startMonitoringSignificantLocationChanges()
After returning a current location fix, the receiver generates update events only when a significant change in the user’s location is detected. It does not rely on the value in the distanceFilter property to generate events
If you start this service and your app is subsequently terminated, the system automatically relaunches the app into the background if a new event arrives. In such a case, the options dictionary passed to the application(:willFinishLaunchingWithOptions:) and application(:didFinishLaunchingWithOptions:) methods of your app delegate contains the key location to indicate that your app was launched because of a location event. Upon relaunch, you must still configure a location manager object and call this method to continue receiving location events. When you restart location services, the current event is delivered to your delegate immediately. In addition, the location property of your location manager object is populated with the most recent location object even before you start location services.
Apps can expect a notification as soon as the device moves 500 meters or more from its previous notification. It should not expect notifications more frequently than once every five minutes. If the device is able to retrieve data from the network, the location manager is much more likely to deliver notifications in a timely manner.
Hope It helps
Related
I have an app which supports background monitoring. For my app to be able to register background movement of device I must call startMonitoringSignificantLocationChanges(). However, at some point in my code I must also call startUpdatingLocation().
My question is, if I call startMonitoringSignificantLocationChanges() and later in my code I call startUpdatingLocation(), will significant monitoring be overridden? Specifically, if I terminate my app will my location manager still receive updates on significant location changes?
After a few testings I’ve come to a conclusion that even if “live” location updates are activated, significant location changes notifications will still be received while running app in background or when terminated. Hope others will find this useful.
I require the user running location and route map path, When an application is Terminate or Background mode.
Currently I am using significant location for application kill mode, but we are not getting proper distance and route.
Because didUpdateLocations is called after some specific interval so that I am not getting proper distance.
Please guide.
According to Apple docs :
Apps can expect a notification as soon as the device moves 500 meters
or more from its previous notification. It should not expect
notifications more frequently than once every five minutes. If the
device is able to retrieve data from the network, the location manager
is much more likely to deliver notifications in a timely manner.
This is why startMonitoringSignificantLocationChanges() would not work reliably for tracking user location change other than driving/public-transport.
Now, coming back to your problem of having to track user location when app is terminated, unfortunately you cannot track location when the app is terminated
If your app is terminated either by a user or by the system, the system doesn’t automatically restart your app when new location updates arrive. A user must explicitly relaunch your app before the delivery of location updates resumes. The only way to have your app relaunched automatically is to use region monitoring or the significant-change location service.
I'm doing an app to trigger a local notification when a region is entered.
However, sometimes when the phone is locked, the notifications didn't pop up even I've been in the region area for a while. The notification popup will show only when the power/home button is pressed(phone still in locked mode).
In general, all seems to be working except that sometimes the notification will show only when power/home button is pressed to awake the phone although it is still locked.
Hope someone can enlighten me please! =)
According to the developer documentation. In core-location framework, two services can give you the current location information.
The standard location service is a configurable, general-purpose solution for getting location data and tracking location changes for the specified level of accuracy.
The significant-change location service delivers updates only when there has been a significant change in the device’s location, such as 500 meters or more.
You need to use standard location services to keep monitoring location in background
If your iOS app must keep monitoring location even while it’s in the background, use the standard location service and specify the location value of the UIBackgroundModes key to continue running in the background and receiving location updates. (In this situation, you should also make sure the location manager’s pausesLocationUpdatesAutomatically property is set to YES to help conserve power.)
I apologise for the redundancy of this topic, but in spite all the given answers, I can't identify the possibility of getting accuracyBest location updates when the app is terminated.
I don't want to use monitoringSignificantChange, I want the best possible accuracy; I won't submit the app on the AppStore, so Apple restrictions are not a problem either.
I have gone through these:
-Location update even when app is killed/terminated
-iOS update location even when app is terminated
-Working with location updates when app is terminated
-http://mobileoop.com/getting-location-updates-for-ios-7-and-8-when-the-app-is-killedterminatedsuspended
and many more, but it is not clear whereas it's possible or not. I currently have my project, everything works great with significantChange but I now need better accuracy.
Could somebody tell me straight forward if getting best accuracy location update when app is killed is possible please ?
Thank you infinitely,
Looking at the below content from the Apple doc, you clearly have 2 alternatives against using significant location changes to wake a app from the background. I have marked in bold the services you can use to relaunch the app if it has been terminated.
Using Location Services in the Background Most location services are
meant to be used while your app is in the foreground but some can also
run in the background. In some cases, location events can even cause
your app to be relaunched to process an event. To run most location
services in the background, you need to enable the location updates
background mode in the Capabilities tab of your Xcode project. For
services that launch your app, you need to request (and be granted)
“Always” authorization from the user.
The standard location service delivers events normally while an app is
running in the foreground. When your app is in the background, this
service delivers events only when the location-updates background mode
is enabled for the app. This service does not relaunch iOS apps that
have been terminated.
The significant location change service delivers events normally
while an app is running in the foreground or background. For a
terminated iOS app, this service relaunches the app to deliver
events. Use of this service requires “Always” authorization from the
user.
The region monitoring service delivers events normally while an
app is running in the foreground or background. (You can use this
service for both geographic and beacon regions.) For a terminated
iOS app, this service relaunches the app to deliver events. Use of
this service requires “Always” authorization from the user.
Beacon ranging delivers events normally while an app is running in the
foreground. When your app is in the background, this service delivers
events only when the location-updates background mode is enabled for
the app and the standard location service is running. (If the beacon
region’s notifyEntryStateOnDisplay property is YES, waking the device
causes the app to range for beacons for a few seconds in the
background.) This service does not relaunch iOS apps that have been
terminated; however, you can be relaunched by monitoring beacon
regions using the region monitoring service.
The heading service delivers events normally while an iOS app is
running in the foreground. When your app is in the background, this
service delivers events only when the location-updates background mode
is enabled for the app and the standard location service is running.
This service does not relaunch iOS apps that have been terminated.
The visit service delivers events normally while an iOS app is
running in the foreground. When your app is in the background, this
service delivers events only when the location-updates background mode
is enabled for the app and the standard location service is running.
For a terminated iOS app, this service relaunches the app to deliver events. Use of this service requires “Always” authorization from the
user.
Enabling the location-updates background mode ensures that an app
continues to receive location events while in the background. When the
app moves to the background, the system adds the location-services
indicator to the status bar to let the user know that an app is using
location services. The system may still terminate the app at any time
to reclaim its memory or other resources.
Also from the doc,
Getting the Visited Locations
In iOS, the visits service provides an alternative to the significant location change service for apps that need location
information about interesting places that the user visited. For
example, if the user is in one location for an extended period of
time, the service might generate an event when the user arrives at
that location and another when the user leaves that location. The
service is intended for apps that might already be using the
significant location change service and want an even lower power way
to do so. You would not use this service to create navigation apps or
apps that rely on regular location updates.
Document Link:
https://developer.apple.com/library/ios/documentation/CoreLocation/Reference/CLLocationManager_Class/index.html#//apple_ref/doc/uid/TP40007125-CH3-SW73
Continuous location updates stop when your app is terminated.
Geo-fence notices will re-launch your app even if it's not running. I think a significant location change will also relaunch you're app but I'm not as sure about that.
Once you're relaunched you can start location updates again with the accuracy set to best like you want, but I think you're going to need to use one of those two APIs to get relaunched again after you've been terminated.
Does the iOS Location Manager's SignificantLocationChange wake the application if the phone is asleep (e.g., in pocket of user)?
From Location awareness programming guide:
If you leave this service running and your application is subsequently suspended or terminated, the service automatically wakes up your application when new location data arrives. At wake-up time, your application is put into the background and given a small amount of time to process the location data. Because your application is in the background, it should do minimal work and avoid any tasks (such as querying the network) that might prevent it from returning before the allocated time expires. If it does not, your application may be terminated.