iPhone how to access the notification center programmatically - iphone

Question

As per the Apple guide:
If the application icon is tapped on a device running iOS, the application calls the same method, but furnishes no information about the notification . If the application icon is clicked on a computer running
https://developer.apple.com/library/ios/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/Introduction.html#//apple_ref/doc/uid/TP40008194
As far as I have known, it seems not be able to detect the notification when the application icon is tapped.
So I tried to retrieve the notification center programmatically but it also seems to be impossible.
Is it impossible to retrieve the notification center programmatically?
What I want to do is detecting whether the notifications received or not even when the application is in the background.

Answer 1

Is it impossible to retrieve the notification center programmatically?
No, it's not possible with any public API.
Your app is agnostic about the current state of the Notification Center, as they are two decoupled entities.
Anyway, as noted by AdamG, in iOS 7 you can implement
application:didReceiveRemoteNotification:fetchCompletionHandler:
which, according to the documentation, is called regardless of the state of your app (so even when it's not running or in background).
In order to use it, you have to support the remote-notification background mode. Here's how:
In Xcode 5 and later, you declare the background modes your app supports from the Capabilities tab of your project settings. Enabling the Background Modes option adds the UIBackgroundModes key to your app’s Info.plist file. Selecting one or more checkboxes adds the corresponding background mode values to that key.
Now, while you still cannot programmatically access to the Notification Center, you can track the notifications as they come.
An mocked implementation would go as follows:
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler {
// Hey we got a notification!
// Now we have 30 seconds to do whatever we like...
// ...and then we have to call the completion handler
completionHandler(UIBackgroundFetchResultNoData);
}

Answer 2

Under iOS 7 there is a way to do this.
- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult result))handler
And then do whatever you need to do in the app to handle the notification and make sure to register that it was received by the phone.
When a push notification arrives, the system displays the notification to the user and launches the app in the background (if needed) so that it can call this method. Use this method to download any data related to the push notification. When your method is done, call the block in the handler parameter.
Found here.