How can you get the payload of a push notification if app is already running in the background when the user taps the notification?

Question

If a push notification is displayed to the user and the user taps it and the app is brought to the foreground from a background state then how can the app get the payload of the notification?

Because the app is already running didFinishLaunchingWithOptions: won't get called and because the app was in the background when the push arrived didReceiveRemoteNotification: won't have been called.

Answer 1

"because the app was in the background when the push arrived didReceiveRemoteNotification: won't have been called."

This, or didReceiveRemoteNotification:withExpirationHandler, should get called if the app is in the background and gets switched to the foreground when the user taps on the notification.

However I got into a situation when this wasn't working as the reason was the content of the push was incorrect, I can't remember the details but double check what's in there.

Answer 2

There are two places so I usually make a method that handles both something like this:

- (void)handleMessageFromRemoteNotification:(NSDictionary *)userInfo

Then in: application:didFinishLaunchingWithOptions:

if ([launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey]) {
        [self handleMessageFromRemoteNotification:launchOptions[UIApplicationLaunchOptionsRemoteNotificationKey]];
}

also in: application:didReceiveRemoteNotification: [self handleMessageFromRemoteNotification:userInfo

If you want to do something different if the app is running check application.applicationState == UIApplicationStateActive in didReceiveRemoteNotification

Answer 3

According to Apple documentation the method didFinishLauchingWithOptions: is called when the user taps the action button of the notification.

As a result of the presented notification, the user taps the action button of the alert or taps (or clicks) the application icon. If the action button is tapped (on a device running iOS), the system launches the application and the application calls its delegate’s application:didFinishLaunchingWithOptions: method (if implemented); it passes in the notification payload (for remote notifications) or the local-notification object (for local notifications).

Then in this method it is easy to recover the content of the notification by doing for example :

UILocalNotification *localNotif =
    [launchOptions objectForKey:UIApplicationLaunchOptionsLocalNotificationKey];
if (localNotif) {
    NSString *itemName = [localNotif.userInfo objectForKey:ToDoItemKey];
    [viewController displayItem:itemName];  // custom method
    app.applicationIconBadgeNumber = localNotif.applicationIconBadgeNumber-1;
}