Get Location Updates for iOS App Even when Suspended
On early 2014, Apple has updated the iOS 7.0 to 7.1 in order to allow location updates even when the app is not active on foreground and not in the background. How do we do that?
I have read some articles like Apple's iOS 7.1 will fix a geolocation bug. But Apple didn't provide much communication related to that nor any sample code on how to get the location update even when the app is killed/terminated/suspended.
I have read the Release Notes for iOS 7.1. I couldn't find anything related to that as well.
So, how do we actually get the location update for iOS 7 and 8 even when the app is suspended?
Answer
After months of trials and errors by experimenting the Core Location Framework, I have found the solution to get location update even when the app is killed/suspended. It works well for both iOS 7 and 8.
Here is the solution:-
If your app is a location based mobile application that needs to monitor the location of the device when it has significant changes, the iOS will return you some location coordinates when the device has moved more than 500 meters from the last known location. Yes, even when the app is killed/suspended either by the user or iOS itself, you still can get the location updates.
So in order for a locationManager to get location update even when the app is killed/suspended, you must use the method startMonitoringSignificantLocationChanges, you can not use startUpdatingLocation.
When iOS wants to return the location update to the app, it will help you to relaunch the app and return a key UIApplicationLaunchOptionsLocationKey to the app delegate method didFinishLaunchingWithOptions.
The key UIApplicationLaunchOptionsLocationKey is very important and you must know how to handle it. You must create a new locationManager instance when you receive the key and you will get the location update on the locationManager delegate method didUpdateLocations.
Here is the sample code:-
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{
self.shareModel = [LocationShareModel sharedModel];
if ([launchOptions objectForKey:UIApplicationLaunchOptionsLocationKey]) {
self.shareModel.anotherLocationManager = [[CLLocationManager alloc]init];
self.shareModel.anotherLocationManager.delegate = self;
self.shareModel.anotherLocationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
self.shareModel.anotherLocationManager.activityType = CLActivityTypeOtherNavigation;
if(IS_OS_8_OR_LATER) {
[self.shareModel.anotherLocationManager requestAlwaysAuthorization];
}
[self.shareModel.anotherLocationManager startMonitoringSignificantLocationChanges];
}
return YES;
}
In addition to the didFinishLaunchingWithOptions method, I have created the locationManager instance when the app is active. Here are some code examples:
- (void)applicationDidEnterBackground:(UIApplication *)application
{
[self.shareModel.anotherLocationManager stopMonitoringSignificantLocationChanges];
if(IS_OS_8_OR_LATER) {
[self.shareModel.anotherLocationManager requestAlwaysAuthorization];
}
[self.shareModel.anotherLocationManager startMonitoringSignificantLocationChanges];
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
if(self.shareModel.anotherLocationManager)
[self.shareModel.anotherLocationManager stopMonitoringSignificantLocationChanges];
self.shareModel.anotherLocationManager = [[CLLocationManager alloc]init];
self.shareModel.anotherLocationManager.delegate = self;
self.shareModel.anotherLocationManager.desiredAccuracy = kCLLocationAccuracyBestForNavigation;
self.shareModel.anotherLocationManager.activityType = CLActivityTypeOtherNavigation;
if(IS_OS_8_OR_LATER) {
[self.shareModel.anotherLocationManager requestAlwaysAuthorization];
}
[self.shareModel.anotherLocationManager startMonitoringSignificantLocationChanges];
}
I have written an article explaining on the details on how to get the location update for iOS 7 and 8 even when the app is killed/suspended. I have also uploaded the complete source code on GitHub with the steps on how to test this solution.
Please visit the following URLs for more information:-