How to keep iphone ios websocket connection alive while in the background?

Question

I created a chat application using SocketRocket,when I quit the app(enter background mode) I want to receive the chat message! so i could do that by calling it a VoIP app but some people says Apple will reject it from the App Store unless it also truly does VoIP. So how can I do that and if the only way to do that is by calling it a VoIP app how does whatsapp handles this situation??

Here's what i did to keep the app alive in the background:

- (void)applicationDidEnterBackground:(UIApplication *)application
{


 NSLog(@"Application entered background state.");
    NSAssert(self.backgroundTask == UIBackgroundTaskInvalid, nil);
    self.didShowDisconnectionWarning = NO;

self.backgroundTask = [application beginBackgroundTaskWithExpirationHandler: ^{
    dispatch_async(dispatch_get_main_queue(), ^{
        NSLog(@"Background task expired");
        if (self.backgroundTimer)
        {
            [self.backgroundTimer invalidate];
            self.backgroundTimer = nil;
        }
        [application endBackgroundTask:self.backgroundTask];
        self.backgroundTask = UIBackgroundTaskInvalid;
    });
}];

dispatch_async(dispatch_get_main_queue(), ^{
    self.backgroundTimer = [NSTimer scheduledTimerWithTimeInterval:10 target:self selector:@selector(timerUpdate:) userInfo:nil repeats:YES];
});

}


- (void) timerUpdate:(NSTimer*)timer {
    UIApplication *application = [UIApplication sharedApplication];

    NSLog(@"Timer update, background time left: %f", application.backgroundTimeRemaining);

    if ([application backgroundTimeRemaining] < 60 && !self.didShowDisconnectionWarning)
    {
        UILocalNotification *localNotif = [[UILocalNotification alloc] init];
        if (localNotif) {
            localNotif.alertBody = @"Background session will expire in one minute.";
            localNotif.alertAction = @"OK";
            localNotif.soundName = UILocalNotificationDefaultSoundName;
            [application presentLocalNotificationNow:localNotif];
        }
        self.didShowDisconnectionWarning = YES;
    }
    if ([application backgroundTimeRemaining] < 10)
    {
        // Clean up here
        [self.backgroundTimer invalidate];
        self.backgroundTimer = nil;

        [application endBackgroundTask:self.backgroundTask];
        self.backgroundTask = UIBackgroundTaskInvalid;
    }

}

Answer 1

I believe your only option is to use remote notifications. You need your app to register for them, and your server to detect when your app is not running (i.e. connected via the socket), and then send a notification instead.