CODEWITHSUNDEEP
iosobjective-cparse-platformapple-push-notifications
Michel
Michel

Reputation: 11755

(silent) RemoteNotification

In an iOS app using remote notifications (coming from Parse.com) I have arrived, after spending some time researching on the subject, to the conclusion that I should not use remote notifications in the background or possibly use silent notifications.

But silent notification seem quite complex.

For example:

In this code:

- (void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo
fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler
{
    NSLog(@"application:didReceiveRemoteNotification:fetchCompletionHandler:");
    completionHandler(UIBackgroundFetchResultNewData);
}

The fact of adding the last line (completionHandler) prevents an error message. But what does this do exactly? Where does this completionHandler come from?

I have never touched silent-notifications and I am kind of lost there.

Upvotes: 0

Views: 63

Answers (1)

Nilesh Patel
Nilesh Patel

Reputation: 6394

The last line is completing block that will be called when you application is in background. 

- (void)application:(UIApplication *)application
didReceiveRemoteNotification:(NSDictionary *)userInfo

Above method get called when your application in running in background OR foreground mode. 

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

If you enabled the remote notifications background mode, the system launches your app (or wakes it from the suspended state) and puts it in the background state when a remote notification arrives.

When a remote 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. Launching your app in the background gives you time to process the notification and download any data associated with it, minimizing the amount of time that elapses between the arrival of the notification and displaying that data to the user.

Let me know if you need anymore clarification.

Upvotes: 1

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