Organizational Research By

Surprising Reserch Topic

Experts Most Trusted Topic


push notifications that trigger a background refresh before showing the push not using -'ios,objective-c,push-notification'


push notifications that trigger a background refresh before showing the push not  using -'ios,objective-c,push-notification'

I want to implement background refresh functionality in my app for when a push is received. Just before the push notification is displayed to the user I want to download the new messages from my backend (Parse.com) and save them to an array. I am following a guide from here: http://developer.xamarin.com/guides/ios/application_fundamentals/backgrounding/part_3_ios_backgrounding_techniques/updating_an_application_in_the_background/

I'm not sure how accurate this guide is. It states: iOS 7 (and greater) extends ordinary push notifications by giving applications a chance to update content in the background before notifying the user, so that the user can open the application and be presented with new content immediately.

So I tried implementing my background push like this:

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler
{


    if([[userInfo objectForKey:@"aps"] objectForKey:@"content-available"]){

        NSLog(@"Doing the background refresh");
        UINavigationController *navigationController=(UINavigationController *)[[[UIApplication sharedApplication] keyWindow] rootViewController];

        MyViewController *myViewController = (MyViewController *)[[navigationController viewControllers] objectAtIndex:1];

        [myViewController.currentUser refreshMessagesArrayWithCompletionHandler:^(BOOL successful, BOOL newMiaos) {

            NSLog(@"messages refreshed the array now has %lu messages",(unsigned long)[myViewController.currentUser.messages count]);
            handler(UIBackgroundFetchResultNewData);
        }];
    }
}


The background refresh is called and the push is displayed, however the push notification does not wait for the background task to finish. It is just displayed as soon as it is received. Is this correct functionality? The tutorial above suggests that a notification won't be displayed until the background task is completed.

I then went about trying a silent notification, this triggers the app to download the messages in the background when the push is received but no notification is displayed. So I do this by firing a local notification instead after the download completes. Is this really the correct way of doing it? Do traditional apps such as whatsapp trigger a background refresh using a silent notification and then fire a local one? Seems a bit hacky. Surely the idea of a background push is to get the data ready before showing the notification but it doesn't quite work like that..

The other thing I noticed is that silent notifications are rate limited they have a lower priority than a typical push notification so surely this hinders the efficiency of the app also...

Any pointers on this would be really appreciated. Just trying to get my head around if I'm approaching this the right way or not. All seems very hacky...
    

asked Sep 7, 2015 by rajesh
0 votes
15 views



Related Hot Questions



Walkin Jobs Opening



Government Jobs Opening


...