Startupdatelocations in Background, Didupdatingtolocation Only Called 10-20 Times

StartUpdateLocations in Background, didUpdatingToLocation only called 10-20 times

Apple has introduced a new policy in iOS 7. iOS 7 does no longer deliver location updates in the background if you call „startUpdatingLocation“ while the App is in the background. You only get update when the App is brought to the foreground in this case.

When you’re using the geofencing feature, your App just gets a few seconds each time you get a RegionEntered/Exited notification to process this notification. And in these few seconds you may also get location updates. After these few seconds are over iOS 7 just suspends your App again.

You can use background task to get more than just a few seconds, but in iOS 7 Apple has also reduced the time Apps can run in the background from 10 minutes (iOS 6 and older) to only 3 minutes under iOS 7. It looks like that these 3 minutes are the total amount for the whole time the App is in the background. Which means you can not ask iOS 7 10 times to get 1 minute background time, you’ll only get 3 minutes in total, so after the 3rd time you’ve asked for a minute, your App won't get any background time anymore at all.

Your only chance in getting location updates in the background is to call „startUpdatingLocation“ while the App is in the foreground. This is sad especially when you only need location updates in response to Region(Enter/Exit messages, because you need to let the location updates running all the time. But you can at least reduce the battery usage by setting the accuracy value to kCLLocationAccuracyThreeKilometers when
you do not need location updates and set the accuracy to kCLLocationAccuracyBest only when you really need the geo coordinates. The iOS won’t power up GPS for the kCLLocationAccuracyThreeKilometers value, so the battery usage would be moderate in this case.

Also the value kCLLocationAccuracyBestForNavigation for the accuracy seems to cause problems under IOS 7. I do not get any location updates with this value if the device is not connected to a an external power supply.

All in all the new iOS 7 policy for location updates is making it much harder to develop certain kinds of Apps. Instead of registering for location updates only when needed, you are forced to register for these for the while lifetime of your App. Which of course drains the battery a little bit faster, though Apple’s intension for this new policy was probably the opposite.

UPDATE:

After some more testing I’ve found some kind of solution for the problem.
The docs from Apple mention that when using the Significant Location Change API, Apps can receive location updates in the background even if „startUpdatingLocation“ is started in the background.

My first tests didn’t work well. I was registering my App for significant location updates within the region monitoring delegate methods just before calling startUpdatingLocation (so this location service is only enabled when needed), but this still does not deliver location updates in the background as the docs would suggest.

But if you start listening for significant location changes directly after your App is launched (and never switch this off), you can call start „startUpdatingLocation“ while the App is in the background and also receive location updates in the background. The battery usage of having the "significant location change“ feature on all the time seems to be very low, so this will be probably the solution for most Apps.

You have to check if the „significant location change“ feature is available on the device, but it seems that all current devices do support this. Even the 5th generation of iPod Touch does support it (The iPod Touch can not use cell towers for location updates, which is the base method of this feature according to the docs from Apple, so I guess we can assume that all current devices running iOS 7 can use the „significant location update“ API. Though it’s probably a good idea to check if this feature is really available, maybe there are certain circumstances where the feature is not available).

Using the "significant location change“ API might have one disadvantage: The App can be launched in the background (if it was terminated in the background by the iOS to reuse its memory for other Apps) repeatedly and unnecessarily whenever the device has moved „significantly“ (according to the docs: when the cell tower has changed, but no more than once per 5 min). So Apps which only need to be activated, when a certain region is exited or entered, will be launched and informed about location changed all the time, not only at those regions. But I assume this should be still much better than having standard location updates active all the time.

My iPhone 5s drains the battery only 1% over night with the significant location changes active, instead of 12% with having the standard location updates active with the accuracy set to 3km.

Hope this helps all developers who are struggling with the new iOS 7 behavior.

iOS 8 Background Location Update triggered by iBeacon

Thank you all for your responses. It is possible to wake your app up from being killed/suspended/terminated using iBeacons, contrary to what Øyvind Hauge said. And unfortunately, adding the background location mode to your plist does not enable indefinite location updates, as others suggested; I was only ever able to get 3 minutes of execution using that method.

I actually found the solution to my question in this StackOverflow article. The solution is to add just a few lines of code to your app delegate - you need to start another location manager that is monitoring for significant location updates. Here are the lines of code that I added to my didFinishLaunchingWithOptions method in my AppDelegate.m file after declaring anotherLocationManager as a property...

self.anotherLocationManager = [[CLLocationManager alloc] init];
self.anotherLocationManager.delegate = self;
[self.anotherLocationManager startMonitoringSignificantLocationChanges];

I never do anything else using this location manager, I just leave it perpetually running in the background, and for some reason this enables indefinite location updates from a regular call to [locationManager startUpdatingLocation]. I am no longer having the location updates mysteriously stop after 3 minutes. It seems very strange that this was the solution, but it was pretty simple to implement, and hopefully this will help others who are dealing with the same problem.

IOS Getting location updates when app terminated without using significantChange

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

Location service going to Inactive state in iPhone 5

Was your app in the background when location service become inactive?

If you don't want to pause location update in background than you need to set pausesLocationUpdatesAutomatically flag,

if ([self.locationManager respondsToSelector:@selector(pausesLocationUpdatesAutomatically)]) {
    self.locationManager.pausesLocationUpdatesAutomatically = NO;
}

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