I saw in several places:
https://www.raywenderlich.com/11395893-push-notifications-tutorial-getting-started
If your app was running either in the foreground or the background, the system notifies your app by calling application(_:didReceiveRemoteNotification:fetchCompletionHandler:). When the user opens the app by tapping the push notification, iOS may call this method again, so you can update the UI and display relevant information.
https://medium.com/fenrir-inc/handling-ios-push-notifications-the-not-so-apparent-side-420891ddf10b
Background: When the notification arrives. + If the user taps the
notification, before the app enters foreground.
that if I set "content-available": 1 and add some data payload to notification, the method application(_:didReceiveRemoteNotification:fetchCompletionHandler) will be called twice (unless I set delegate for UNUserNotificationCenter) when my app is in background and then when user taps on notification.
Unfortunately, I didn't notice such behavior, the method above was only called once after user taps on notification.
The notification I'm trying to send is something like:
{
"aps": {
"alert": "Test",
"sound": "default",
"content-available": 1
},
"test": "abc"
}
Has something changed in iOS 13/14 (the Ray Wenderlich tutorial seems to be up-to-date) or am I missing something?
EDIT
Interestingly, after reinstalling the app multiple times, it started working. I set the UNNotificationCenterdelegate and it works like that:
App is in background, the server sends notification with content-available: 1.
System shows alert and application(_:didReceiveRemoteNotification:fetchCompletionHandler:) is called so I can fetch new data.
User taps on alert, userNotificationCenter(_:didReceive:withCompletionHandler:) is called, so I can navigate to particular view.
Is it a proper way of handling push notifications with data payload?
Related
I´m having trouble on receiving push notifications (background) on a specific device running iOS 10. Other phones with iOS 9 are doing fine.
Although if I open the app the notification shows a banner that I implemented. Why does not show anything in background state?
Reading the firebase documentation something made me a little confused
According to a github firebase example on the following link https://github.com/firebase/quickstart-ios/blob/master/messaging/FCMSwift/AppDelegate.swift, there is a comment in the didReceiveRemoteNotification method that says:
// If you are receiving a notification message while your app is in
the background, // this callback will not be fired till the user taps
on the notification launching the application. // TODO: Handle data of
notification
So it my app is in background, does not apple do the whole thing to make that default iOS notification?
Does the content_available value interfere on this? I also send notification and data values.
Here is an example of the JSON I send:
{
"content_available": true,
"priority": "high",
"data": {
"post_id": "...",
"push_id": "..."
},
"notification": {
"title": "...",
"body": "..."
},
"registration_ids": ["xxxx"]
}
The expected behaviour would be:
App dead: the system will show the notification
App background: the system will show the notification and call the didReceiveRemoteNotification method.
App active: the system will NOT show de notification and call the didReceiveRemoteNotification method.
Right?
Your assumptions are correct except for number 2. There are several cases where apple will not call didReceiveRemoteNotification you even if you set the content_avaialable.
1) Device has low battery and is in power saver mode
2) App has "background app refresh" disabled
3) Other undocumented scenarios where apple decides not to wake up your app. Apple reserves the right to not deliver notifications for performance reasons.
Having said that, if the user taps the notification you will always get the payload in didReceiveRemoteNotification.
I'm facing a problem with push notifications, I'm using Google Cloud Messaging,
My problem is that my app works with some cached data, and I refresh that cache with the data coming from push notificacions, so when the app is killed by the user (home button + swipe-up) and the app receive a push notification it doesn't call the method didReceiveRemoteNotification, so the app can't access to the payload of that notification and update the cached data.
So, is there a way to achieve this?
Only when the user taps the notifications and the app gets it through the application:didFinishLaunchingWithOptions method?
If the user opens the app by clicking the application icon I can't get the notificaton's payload?
PD: If the app is in foreground or background (not killed) it works perfectly
If you wish your app to receive the push notification even when it is killed, add the key "content-available":"1" to the push payload.
Look here
EDIT:
After digging some more, I found out that silent push (e.g content-available:1), does not wake the app if it was killed by the user:
However, the system does not automatically launch your app if the user has force-quit it
I must say, I can't really understand why the OS does not let my app wake up when silent push arrives when it's dead. What's the point then???
This is the expected behavior. didReceiveRemoteNotification will not be called if the user killed the app, unless your app has VoIP permissions.
In case of killed application. both application:didFinishLaunchingWithOptionsandapplication:didReceiveRemoteNotification:fetchCompletionHandler:are called. In the prior one. The key of notification either remote or local is passed in options parameter. And the later one is called in only case when remote notification. The process is explained in detail in Apple Docs Here. The snapshot is pasted here as well.
Handling an Actionable Notification
If your app is not running in the foreground, to handle the default action when a user just swipes or taps on a notification, iOS launches your app in the foreground and calls the UIApplicationDelegate method application:didFinishLaunchingWithOptions: passing in the local notification or the remote notification in the options dictionary. In the remote notification case, the system also calls application:didReceiveRemoteNotification:fetchCompletionHandler:.
If your app is already in the foreground, iOS does not show the notification. Instead, to handle the default action, it calls one of the UIApplicationDelegate methods application:didReceiveLocalNotification: or application:didReceiveRemoteNotification:fetchCompletionHandler:. (If you don’t implement application:didReceiveRemoteNotification:fetchCompletionHandler:, iOS calls application:didReceiveRemoteNotification:.)
Finally, to handle the custom actions available in iOS 8 or newer , you need to implement at least one of two new methods on your app delegate, application:handleActionWithIdentifier:forRemoteNotification:completionHandler: or application:handleActionWithIdentifier:forLocalNotification:completionHandler:. In either case, you receive the action identifier, which you can use to determine what action was tapped. You also receive the notification, remote or local, which you can use to retrieve any information you need to handle that action. Finally, the system passes you the completion handler, which you must call when you finish handling the action. Listing 2-8 shows an example implementation that calls a self-defined action handler method. Reference Apple Docs
Edit:
The user taps the default button in the alert or taps (or clicks) the app icon. If the default action button is tapped (on a device running iOS), the system launches the app and the app calls its delegate’s application:didFinishLaunchingWithOptions: method, passing in the notification payload (for remote notifications) or the local-notification object (for local notifications). Although application:didFinishLaunchingWithOptions: isn’t the best place to handle the notification, getting the payload at this point gives you the opportunity to start the update process before your handler method is called.
Reference: Apple Docs
When the app is killed and the push notification triggered contains some actionable button. When we click on a Action Button of Push Notification then:
The first delegate that is executed is:
-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
But in here the launchOptions are nil.
The second delegate that is executed is:
-(void)application:(UIApplication *)application handleActionWithIdentifier:(nullable NSString *)identifier forRemoteNotification:(nonnull NSDictionary *)userInfo completionHandler:(nonnull void (^)())completionHandler
In this the variable userInfo contains all the payload of the Push Notification. With the help of identifier we can identify which action was invoked and then perform our respective operations.
add target of notification service extension in your project it contains two methods upper one method call in killed time and add a key "mutable_content" : true in server side of your notification payload
Take an app which is an e-mail client and gets push notifications when a new e-mail has arrived.
How do these apps make sure that when a push notification has arrived it's for the currently logged-in user?
For example, user logs-in with user1 then logs out and logs in with user2.
What if a push notification related to a new e-mail for user1 arrives when user2 is logged in?
From the push notification communication mechanism point of view, this is possible. The push notification can be already on the way when user switches logins.
The problem is on iOS when a new push notification has arrived, your code doesn't get called if the app is not in foreground.
This changed a bit with iOS 7 (https://developer.apple.com/library/ios/releasenotes/General/WhatsNewIniOS/Articles/iOS7.html#//apple_ref/doc/uid/TP40013162-SW10) yoru code gets called, but the push notification is still displayed without your code, meaning you can't decide weather to display it or not. This is different than Android where you can always decide.
This is true, you cannot catch the notification before the system, but... you can instead send a silent push notification, where its payload is something like this:
{
"aps": {
"content-available": 1
},
"user": "someUser",
"alertMsg": "someMessage"
}
which essentially will trigger your application:didReceiveRemoteNotification:fetchCompletionHandler: and give you 30 seconds for processing (if you're on the background) without presenting an alert. You can now check if the logged-in user matches and if it does, fire a local notification with the information from the remote one (or even with data from a network call)
I hope that this makes sense...
I have implemented the UIApplicationDelegate method -(void)application:(UIApplication *)application didReceiveRemoteNotification:(NSDictionary *)userInfo fetchCompletionHandler:(void (^)(UIBackgroundFetchResult))completionHandler to handle push notifications, it works fine. In some situations, I need to retrieve the payload of the push notification. But sometimes this delegation method is not called.
I have a question about retrieving the payload (userInfo) in this scenario:
The app running either in background or not launched. The app received a push notification, a banner is shown, sound is played, and message is displayed, app icon badge increased, and the push notification can be seen in the iOS notification centers. If the user taps the notification when it's shown or in the notification center, the app launches, and the didReceiveRemoteNotification: method is called.
However, if the user just tap the app icon and launch the app in normal ways, the method is not called, and I can't retrieve the userInfo.
From Apple's documentation on handling push notifications:
The notification is delivered when the app isn’t running in the foreground. In this case, the system presents the notification, displaying an alert, badging an icon, perhaps playing a sound, and perhaps displaying one or more action buttons for the user to tap.
The user taps a custom action button in an iOS 8 notification. In this case, iOS calls either application:handleActionWithIdentifier:forRemoteNotification:completionHandler: or application:handleActionWithIdentifier:forLocalNotification:completionHandler:. In both methods, you get the identifier of the action so that you can determine which button the user tapped. You also get either the remote or local notification object, so that you can retrieve any information you need to handle the action.
The user taps the default button in the alert or taps (or clicks) the app icon. If the default action button is tapped (on a device running iOS), the system launches the app and the app calls its delegate’s application:didFinishLaunchingWithOptions: method, passing in the notification payload (for remote notifications) or the local-notification object (for local notifications). Although application:didFinishLaunchingWithOptions: isn’t the best place to handle the notification, getting the payload at this point gives you the opportunity to start the update process before your handler method is called.
If the notification is remote, the system also calls application:didReceiveRemoteNotification:fetchCompletionHandler:.
If the app icon is clicked on a computer running OS X, the app calls the delegate’s applicationDidFinishLaunching: method in which the delegate can obtain the remote-notification payload. If the app icon is tapped on a device running iOS, the app calls the same method, but furnishes no information about the notification.
The highlighted part kinda saying there is no obvious way to access the payload of the push notification in this way. So is there a way to work around this issue?
Thank you!
It is the default behavior of iOS. You will never know the payload unless user opens your app via tapping on the notification.
You can use silent push notifications if you want to send custom data (max 2048 bytes) or commands to your mobile app.
In the push notification set 'content-available' to 1 so you app gets some time to process data and also add your custom content to the notification.
I also use silent push notifications to trigger my apps to update by REST HTTP calls, since my data can be bigger than the max size... The only downside is that Apple might block your background activities if you are battery or processor intensive. Visual push notifications are always delivered.
Things I hate most are visual push notifications like 'you've got a new message' , on which I click sometimes when no data connection is available and the app will not show me the message... You can solve this by sending a silent push notification with data and only if the data could be fetched from the server, or
stored correctly in case you can send it all in the notification, you set a local notification.
Choose between visual and silent push notifications wisely is my only advise.
Check the following link for more official Apple info: https://developer.apple.com/library/content/documentation/NetworkingInternet/Conceptual/RemoteNotificationsPG/CreatingtheNotificationPayload.html
I know this is covered in a lot of places, but I cannot figure this out. I use Urban Airship for push notifications. Everything seems to be fine except that when my app is in the background - didReceiveRemoteNotification is not getting called. It works when in the foreground - I am able to properly process messages. And I am able to get to messages from launch options if message is tapped from notifications center. But when in the background, a message it send - iOS displays the alert - didReceiveRemoteNotification is not called. When I tap on my Application icon (not from within notification center) the app comes to the foreground and I have no idea the notification is present. Any ideas?
application:didReceiveRemoteNotification: will call in the background only when you have added content-available key with value 1 into the notification payload.
In case of the Urban Airship, you can send Test Push under the Setting tab.
Sample Payload for Push Notifications:
{
"aps": {
"alert": "aaaa",
"badge": "+1",
"content-available": "1"
},
"device_tokens": [
"86BA71E361B849E8312A7B943BA6B26A74AB436381CF3FEE3CD9EB436A12A292"
]
}
Apple has clearly mentioned in his documentation....
For a push notification to trigger a download operation, the
notification’s payload must include the content-available key with its
value set to 1. When that key is present, the system wakes the app in
the background (or launches it into the background) and calls the app
delegate’s
application:didReceiveRemoteNotification:fetchCompletionHandler:
method. Your implementation of that method should download the
relevant content and integrate it into your app.
https://developer.apple.com/library/content/documentation/iPhone/Conceptual/iPhoneOSProgrammingGuide/BackgroundExecution/BackgroundExecution.html
From the APNS programming guide :
Let’s review the possible scenarios when the operating delivers a
local notification or a remote notification for an application.
The notification is delivered when the application isn’t running in the
foreground. In this case, the system presents the notification,
displaying an alert, badging an icon, perhaps playing a sound.
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).
If the application icon is tapped on a device running iOS, the application
calls the same method, but furnishes no information about the
notification.
I believe the last sentence describes your case, and explains why your application gets no information about the notification.
didReceiveRemoteNotification is calling ONLY if app in foreground or if app is just launched or is bought from background to foreground
link in Apple and some question
Method didFinishLaunchingWithOptions:(NSDictionary *)launchOptions parameter launchOptions one of the dictionary keys are UIApplicationLaunchOptionsRemoteNotificationKey which holds the pressed push notification info.
You can push received info after tour main root controller is initialised. I save it to some property and then push it after view is initialised.
if (launchOptions) {
if ([launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey]) {
self.notificationToMakeAction = [launchOptions objectForKey:UIApplicationLaunchOptionsRemoteNotificationKey];
}
}