deffered Location updates are not available - ios

Question

I am trying to fetch user locations in foreground & background. I have to call api after I got a locaion update. To work in background I want to use Deferred method. I followed the same process as described in Apple WWDC. I am checking app on iPhone 5 (iOS 7). It is working fine when I am in foreground but did not give me update after I send the app into background. Below is the code which I am using to get location in background.
#import "AppDelegate.h"
#implementation AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.locationArray = [[NSMutableArray alloc] init];
self.locationErrorArray = [[NSMutableArray alloc] init];
self.manager_loc = [[CLLocationManager alloc] init];
self.manager_loc.activityType = CLActivityTypeFitness;
self.manager_loc.delegate = self;
[self.manager_loc setDesiredAccuracy:kCLLocationAccuracyBest];
[self.manager_loc startUpdatingLocation];
return YES;
}
- (void)applicationWillResignActive:(UIApplication *)application
{
// Sent when the application is about to move from active to inactive state. This can occur for certain types of temporary interruptions (such as an incoming phone call or SMS message) or when the user quits the application and it begins the transition to the background state.
// Use this method to pause ongoing tasks, disable timers, and throttle down OpenGL ES frame rates. Games should use this method to pause the game.
}
- (void)applicationDidEnterBackground:(UIApplication *)application
{
// Use this method to release shared resources, save user data, invalidate timers, and store enough application state information to restore your application to its current state in case it is terminated later.
// If your application supports background execution, this method is called instead of applicationWillTerminate: when the user quits.
}
- (void)applicationWillEnterForeground:(UIApplication *)application
{
// Called as part of the transition from the background to the inactive state; here you can undo many of the changes made on entering the background.
}
- (void)applicationDidBecomeActive:(UIApplication *)application
{
// Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
}
- (void)applicationWillTerminate:(UIApplication *)application
{
// Called when the application is about to terminate. Save data if appropriate. See also applicationDidEnterBackground:.
}
#pragma mark - Location Manager Delgate
-(void)locationManager:(CLLocationManager *)manager didFailWithError:(NSError *)error
{
NSLog(#"update failed");
}
-(void)locationManager:(CLLocationManager *)manager didUpdateLocations:(NSArray *)locations
{
[self.locationArray addObject:locations];
NSLog(#"udate locations %f %f", manager.location.coordinate.latitude, manager.location.coordinate.longitude);
if (!self.deferredStatus)
{
self.deferredStatus = YES;
[self.manager_loc allowDeferredLocationUpdatesUntilTraveled:100 timeout:30];
}
[self.manager_loc stopUpdatingLocation];
}
-(void)locationManager:(CLLocationManager *)manager didFinishDeferredUpdatesWithError:(NSError *)error
{if (manager.location != nil)
{ [self.locationArray addObject:manager.location];
}
if (error != nil)
{
[self.locationErrorArray addObject:error.description];
}
self.deferredStatus = NO;
NSLog(#"deffered success %f %f", manager.location.coordinate.latitude, manager.location.coordinate.longitude);
}
#end
If I do not stop the location update in didUpdateToLocations Delegate then the location arrow (on status bar) do not go. In that case it gives me locations contionusly. I want location update after a particular time or particualar distance travelled, so that I can hit server with the user locations. Please help me on this.

Answer 1

Use LocationManger distanceFilter Property for update location at particualar distance travelled.
self.manager_loc.distanceFilter= 100;// In meters

Answer 2

If you want location updated in Backggriound then register your for background updates. Youca can do it in plist.
Set location manager to :
if ([self.locationManager respondsToSelector:#selector(pausesLocationUpdatesAutomatically)]) {
self.locationManager.pausesLocationUpdatesAutomatically = NO;
}
Then If you want to location updated after some time or distance then use:
- (void)allowDeferredLocationUpdatesUntilTraveled:(CLLocationDistance)distance
timeout:(NSTimeInterval)timeout // No guaranty it will work exactly or not
If you want location updated based on distance the you can use
Desired accuracty and distanceFilter property.
self.locationManager.desiredAccuracy = kCLLocationAccuracyThreeKilometers;// Use other accurarcy as your need
self.locationManager.distanceFilter = 3000; //100, 200, etc
If you set activity type to CLActivityTypeFitness all above setting will overrided, And location manager updated according to this activity, which is as per my knowledge will eat Battery.
While using CLLocation Manager one thing you should accept it will not give all updartes 100% accurate.

Answer 3

See my answer for this post: StartUpdateLocations in Background, didUpdatingToLocation only called 10-20 times
If you need location updates in the background under iOS 7, you must call startUpdatingLocation while your App is in the foreground. You can no longer do this while your App is in the background, so you can no longer register for location updates only when you need them and while you need them. You are forced to register for them for the whole time your App is running (in the foreground and the background) and so you’re forced to waste a lot of energy.
You can reduce the battery usage a little bit by setting the accuracy to kCLLocationAccuracyThreeKilometers when you do not need the location updates and set them to kCLLocationAccuracyBest only when you need the updates. But this will nevertheless drain the battery faster than expected.
Please write a bug report to Apple and ask for the „old" behavior of iOS 4,5 and 6, where you could call „startUpdatingLocation“ in the background as well to get location updates in the background. If Apple gets enough requests to change this behavior back to the way it was implemented in iOS 5/6, the more likely it is that Apple will change this back.
The currents situation is really bad. Bad for developers, which are forced to waste energy, or to abandon their Apps, bad for the user, whose device needs to be plugged to a power source much earlier, or who can no longer use certain Apps.