Background Task with NSOperation and NSOperationQueue iOS

Question

I want to upload some files which should continue even if the application goes into background.

Currently I am retrieving the files from the DB and than adding it to the

Answer 1

Why not try doing this? .. I haven't yet tried it out, I'll post an update after attempting this

UIApplication* application = [UIApplication sharedApplication];
bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
  // Clean up any unfinished task business by marking where you
  // stopped or ending the task outright.

  // Bring up your NSOperation queue instance here and block this thread until it is complete
  [queue waitUntilAllOperationsAreFinished];

  [application endBackgroundTask: bgTask];
  bgTask = UIBackgroundTaskInvalid;
}]; 

also ensure that you have a way to cancel all these long standing operation in the background

 bgTask = [application beginBackgroundTaskWithExpirationHandler:^{
        // Clean up any unfinished task business by marking where you.
        // stopped or ending the task outright.
        [queue cancelAllOperations];

        [application endBackgroundTask:endSessionTask];
        bgTask = UIBackgroundTaskInvalid;
    }];

Answer 2

Apple allows background execution if your app follows and satisfy the necessary condition. plese refer here