Develop Reference

Why do Android Push Notifications call Application create and trigger AppStartup

I have noticed that when I send a push notification (Firebase Messaging Service) to my device my Application object is created. This is without clicking on the notification. Simply the act of viewing the notification creates the application. Further, it also starts the Jetpack AppStartup library. I want to be able to use AppStartup and application create. But I don't want to launch that code when a push notification occurs.
Why does Android do this? Is this part of all android notification, or is it a feature of the third-party push notification sdk I am using? And is there a way in Application.create and AppStartup to distinguish a normal app launch from a push notification triggered launch?
Again, I'm not talking about the user clicking on the notification (and launching the app because of a deeplink). I'm talking about just looking at the notification in the notification dropdown.

Why does Android do this?
Android is starting your app process to run code in your app. Creating an Application instance and calling onCreate() will be part of that, as will creating any ContentProvider objects. IIRC, Jetpack Startup uses a ContentProvider to get control early in your process, though I am not 100% certain of that.
The reason why Android is starting your app process is because your app is causing the Notification to be displayed — specifically, Firebase Cloud Messaging is doing that. If I remember the protocol correctly, Play Services is sending a broadcast Intent that Firebase Cloud Messaging in your app will respond to, and part of that code will be displaying the Notification.
And is there a way in Application.create and AppStartup to distinguish a normal app launch from a push notification triggered launch?
onCreate() of an Application subclass has no means of knowing what specifically caused the process to be created, as there can be many possible reasons. If by "AppStartup" you mean Jetpack Startup, I do not recall it having any options here, but I have not spent much time with its API.

Codename One iOS Remote Notifications

We have been trying for the last two weeks to get a reliable solution to try and sync our app data with a server in the background. We have tried the Background fetch mechanism but due to the iOS restrictions on when it runs it is not a viable solution.
iOS does provide Remote Notifications (https://developer.apple.com/documentation/usernotifications/setting_up_a_remote_notification_server/pushing_background_updates_to_your_app?language=objc) that we would like to use as we can use the same mechanism on Android.
The issues is that when sending a type 2 notification CN1 only delivers the notification when the app is brought to the foreground by the user.
On Android I see there is a Build Hint for android.background_push_handling that allows the notifications to be sent to the app even if it is in the background.
Is there a similar build hint that we can use for iOS?
If not, is there a way then to override the application:didReceiveRemoteNotification:fetchCompletionHandler: method that fires when the Notification arrives so that we can forward it to our app?

You can use silent push notifications for that purpose. To send a silent push notification you just have to include "content-available" : 1" into the body of the notification. More info on that here: Apple docs-silent push notifications
You should bear in mind that this will only work when your app is in the background, it won't work when the app is killed. When the app is killed the only solution is standard push notifications, unless your app has VoIP functionality, in which case you are allowed to use PushKit framework (if you use it in an app without VoIP functionality, you won't get pass the AppStore).

Sending Android Notifications between app users

I am currently aiming to make an app in Android Studio that allows one user to push a button and another user to receive a push notification as a result. How might I do this?

You're going to need a server to act as an intermediary. Set up an API endpoint that your app can call to request a notification, and have your server dispatch a message to the receiving device using something like FCM.

Firebase Push Notifications not received if app is closed

I'm testing Firebase Push notifications, sending a notification from the Firebase composer panel, and I noticed that if I close the app process from App Information panel, the push notifications sent doesn't reach the device. Even if I start again the app the notification is lost and is never received.
I also tryed this:
close the app process -> shut down the device -> power on the device -> send a notification... and the notification is not received!
It seems that firebase can only receive notifications if the device has the app started and not 100% closed, I mean, closing it just with back key but not killing the app process.
How is this possible? It is supossed that firebase should receive notifications even with the app closed.
I'm testing on a Nexus 5X with Android 8.0 and I'm using the last version of Firebase push Notifications.

Sorry for the late, but hope this help next users that will have this problem because there is no answer selected as "Solution".
When setup correctly the service, this will work even the app is closed. That because, Firebase Messages travel by Google Play Services so closing your app doesn't have a relation with the service.
At first, notification never came. By searching in the device settings I saw that the energy saving system for my app was active (when closed was removed from stack) so notification was sent but my app couldn't take and display these.
After disabling that option, I've test many time and I found that sometimes notification come with a late of 2-3 minutes when app is completely closed. Sometimes it touch the 5 minutes. You need to be patient and it will come!
Instead, When app is opened or closed simply by back button, notification come in few seconds.

In your AndroidManifest.xml file remove android:exported=false from your Messaging service.
Explanation: When your app is completely killed or removed from back stack. OS tries to restart the messaging service but if there is android:exported=false in your manifest file then OS will not able to restart the service because such service can only be restarted by the same app.
Reference: https://developer.android.com/guide/topics/manifest/service-element#exported

It seems that firebase can only receive notifications if the device
has the app started and not 100% closed, I mean, closing it just with
back key but not killing the app process.
No, FCMs are sent to all the devices that have Google Play services and the targeted application. That is why it is called Push Notifications.
Your application also get notifications when it is running, to handle those you need to override
onMessageRecieved(RemoteMessage mes);
There could be many reasons for the app not getting notifications. Some of them could be :
Messaging Services not included in the Manifest
Play services not configured correctly. Or not present in the Phone.
Sometimes Latency is High (rarely). I noticed it sometimes take take about 2-3 minutes
after composing.
SHA1 fingerprint not registered in Console and/or updated google-services.json not present in sources.
Uninstall and reinstall the app. So that token Regeneration may take place.
Please follow this link to get started with messaging.
https://firebase.google.com/docs/cloud-messaging/android/client

Have you added firebase services on Java code?
Here is the link: firebase/quickstart-android
You have to add those 3 java file in java folder and also add those service name in AndroidManifest.xml

if you are sending it from your firebase console it sends a notification message so those you will not get if your app is closed, you need to send messages that have the data payload which the console does not do.
https://firebase.google.com/docs/cloud-messaging/concept-options#notifications_and_data_messages

Took this screenshot from Firebase documentation, seems its not possible with FCM

Air iOS/Android push notification remember when app launches

I have an app built for iOS and Android which has push notifications. Everything is working great however I was wondering if there is a way to store the data of the push notification in the app so that when users launch the app after receiving a notification I can show them the message again?
Basically I allow users to share information and/or chat amongst their friends. If they receive a notification when the app is in the background it comes through as a normal push message but when they launch the app I would like to direct them to the chat feature to see the message again.
I am storing the messages sent in a remote DB but seeing as they have already received the payload it doesn't make much sense for the app to call the remote DB to retrieve the same message.
I am using Distriqt's extensions in AS3 and Air 3.5.
Cheers

I asked Distriqt's support for the same thing a few weeks ago and they explained that there is no way to get the information of the push notification message while the app is closed so they suggested this :
- when the user opens the app, you call your server to check if they haven't missed anything, and get the data from there. If there has been a push, you display the push message as if it was received with the app in the foreground.
It's a bit tricky and not very satisfying but it works.. As long as the user follows the path.
If your user receives the push and chooses not to open your app, he will still get the push message in your app next time he opens it.

I was having trouble figuring this out too but I found a solution! Basically if a user launches an app (not running in the background) by way of a notification it comes through in the Invoke event, not the usual Notification event. So do this:
NativeApplication.nativeApplication.addEventListener(InvokeEvent.INVOKE, invoked);
private function invoked(evt:InvokeEvent):void
{
if (evt.reason == InvokeEventReason.NOTIFICATION)
{
var payload:Object = Object(evt.arguments[0]);
// do stuff
}
}
That's pretty much it. There's more detail in this blog post here: http://blogs.adobe.com/airodynamics/2012/05/29/push-notifications-support-in-ios/

NativeApplication.nativeApplication.addEventListener(InvokeEvent.INVOKE, invoked);
doesn't work correctly for Android push notification. Android starts with InvokeEventReason.standard all the time, so we cant receive message. It works only for iOS.