iOS background Location not sending http request

Question

My app needs to track the users location in the background but it is failing to send a \'get\' request. The http request gets sent immediately when the app comes to the foregrou

Answer 1

I'm using exactly the same code as you and it works for me in RestKit. The only way I could make it work is ny creating a synchronous request (it doesn't make a lot of sense to do it asynchronously in this context anyway!). Please check this code and let us know if it works:

// REMEMBER. We are running in the background if this is being executed.
// We can't assume normal network access.
// bgTask is defined as an instance variable of type UIBackgroundTaskIdentifier

// Note that the expiration handler block simply ends the task. It is important that we always
// end tasks that we have started.

_bgTask = [[UIApplication sharedApplication] beginBackgroundTaskWithExpirationHandler:
           ^{
               [[UIApplication sharedApplication] endBackgroundTask:_bgTask];
           }];

// ANY CODE WE PUT HERE IS OUR BACKGROUND TASK

// For example, I can do a series of SYNCHRONOUS network methods (we're in the background, there is
// no UI to block so synchronous is the correct approach here).

NSNumber *latNumber = [NSNumber numberWithDouble:location.coordinate.latitude];
NSNumber *lngNumber = [NSNumber numberWithDouble:location.coordinate.longitude];
NSNumber *accuracyNumber = [NSNumber numberWithDouble:location.horizontalAccuracy];
NSDictionary *params = [NSDictionary dictionaryWithKeysAndObjects:@"lat",latNumber,@"lng",lngNumber,@"accuracy",accuracyNumber, nil];
RKURL *URL = [RKURL URLWithBaseURL:[NSURL URLWithString:SERVER_URL] resourcePath:@"/user/location/update" queryParameters:params];
RKRequest *request = [RKRequest requestWithURL:URL];
request.method = RKRequestMethodGET;
NSLog(@"Sending location to the server");
RKResponse *response = [request sendSynchronously];
if (response.isFailure)
    NSLog(@"Unable to send background location, failure: %@", response.failureErrorDescription);
else {
    NSError *error = nil;
    NSDictionary *parsedBody = [response parsedBody:&error];
    if (YES == [[parsedBody objectForKey:@"result"] boolValue]){
        NSLog(@"Background location sent to server");
    }
    else {
        //Something went bad
        NSLog(@"Failed to send background location");
    }
}
// AFTER ALL THE UPDATES, close the task

if (_bgTask != UIBackgroundTaskInvalid)
{
    [[UIApplication sharedApplication] endBackgroundTask:_bgTask];
    _bgTask = UIBackgroundTaskInvalid;
}

I'm almost sure the new thread spawned for your RKClient request is automatically killed after invoking it.

Answer 2

When you're application is running in the background you can finish a HTTP request you started before you entered the background but you cannot initiate a new request. You can only initiate certain network operations while in the background (voip, newsstand).

Answer 3

Re-creating original suggestion as an answer

Have your try replacing your restKit calls with a stock synchronous NSURLConnection? – dklt Sep 20