Notifications when app is closed - Flutter - flutter

I'm looking for a way to send notifications to the user every time my database, in this case Firestore, is changed, even when the application is closed. Any ideas on how I can do that? My application is a messaging app, so I need my user to receive a notification every time a new message arrives, even if the application is closed.
At the moment I just configured local notifications and looked for solutions on YouTube, but I didn't find anything.

Related

How to automatically send a scheduled notification everyday in Flutter

I have an app that needs to send a reminder notification everyday at a user specified time. For now, I have used flutter_local_notification and used the zoneSchedule method to send a notification locally for that particular day after fetching the time from firebase.
My question is how should I make it so that this notification is sent everyday? When should the scheduling happen.
The specified time can be changed by the user.
I'd like the notification to be sent even when there is no internet connection.
If the app is not in the foreground the app is suspended, so your code wont execute.
You can wake up the app via a push notification from an external source but this will not work if the app has no internet connection.
If you want to execute it without an internet connection, you have to register a background task.
See:
https://docs.flutter.dev/development/packages-and-plugins/background-processes
https://pub.dev/packages/workmanager

How to send notifications even if app is closed or phone is restarted in xamarin forms?

I am new in mobile programming. I need an application. This application periodically will check web api to get whether the client has a new massage or not. If there is a new massage, this massage will be informed to the client by notification. I achieved this but it works if application is open. Then I used foreground services, but it failed when phone is restarted. I need a notification system like whatsapp or telegram. We can get notifications about new massage even if the apps are closed or when we restart phone.
Please help me.
I recommend using Firebase push notifications - sample

How to handle multiple push notifications with user data arrived at different times?

My app is receiving APNs sent from server to Apple backend. Naturally a user may not open the app once a notification arrives to user's device. In meantime my server may push more notifications. They all contain some user data that is important when a notification is processed. So how to deal with it? iOS won't bundle and give me a batch, will it?
Here are ways how I am going to tackle it, none of which is simple.
Server keeps track of not seen data and upon arriving a new request always sends a batch of all new notifications, reflecting the count as badge count.
Client is opened by taping on notification popup. In this case it has all needed data in didReceiveRemoteNotification.
OR
Client ignores notification popup and opens app (possibly later) by tapping on app icon. In this case didReceiveRemoteNotification is not called and thus app has to fetch all needed data from server.
OR
Server never sends any user data and client always checks for new stuff every time it starts or fetches data in didReceiveRemoteNotification.
Anything else? Something simpler I am missing?
Number 4 is the right approach. There is no guarantee that any of your app code will run when an APN is received, except on iOS7. So when your app starts, it has to check with your servers for any new information that it should display.
It's simplest to code this to alway ask your servers for the latest information to display, rather than rely on the information in the APN. Use the information in the APN only to determine which new information to navigate to, so that the app displays whatever the user tapped on.
This has changed with iOS7, where you can use the remote-notification background mode to be launched whenever a push message arrives. See https://developer.apple.com/library/ios/documentation/UIKit/Reference/UIApplicationDelegate_Protocol/Reference/Reference.html#//apple_ref/occ/intfm/UIApplicationDelegate/application:didReceiveRemoteNotification:fetchCompletionHandler:

Checking for other UIRemoteNotifications waiting, inside didReceiveRemoteNotifications

In didReceiveRemoteNotification, is it possible to see if there are other/older push notifications that haven't been responded to?
I have a scenario where each notification contains different data, and unless you exit app and select every single notification for your app. You app wont be able to get to that data.
I'm thinking that iOS must be storing that information in an array somewhere, but haven't been able to find anything through Google.
Advice please? Last chance saloon would be re-writing it to poll a server for notifications.
You cannot guarantee that your app will ever receive any push notification sent to it. The only way it does is if it is running when it receives the message or if the notification is used to launch your app.
I would recommend implementing a web service on your server that allows your app to pull down the data it needs from these notifications when it is running.

Handle APNS Remote Notifications while in Background

I have implemented all recommended methods in AppDelegate to get working Remote Notifications service.
I can accept them while running, while launching and while turned off.
But there is an issue, since I can't work with many received notifications while in background. I can work only with latest notification.
What is recommended manual to do that? How can I got all notifications received while in background? Is it only solvable via manual call to my service provider (sender of apns data)?
With all the projects I've worked on there hasn't been a way to locally store this information if the push notification is dismissed. In all those cases we used a small file on the server that the app would connect to and pull when it became active again. There was also some place in the app where the user could see all their notifications which, again, were stored on the server for quick retrieval.
With the way I understand push notifications to be setup, if the notification is dismissed the system discards it. It'll perform anything it's supposed to do (such as update the badge number and play the correct sound) but any additional information specific to that notification is lost.
Not sure if this helps, but if you just want to know how many notifications you have missed while you were in background. You can create a variable which contains notification number and store this in the app every time you handle notification. When you come out of background and receive a new notification you can subtract the new number with the stored number to find out the number of missed notifications. I don't think there is a way where iOS can give you complete data associated with all the notification device have received while the app was in background.
The best solution is to keep a list of sent notifications with all relevant data on your server, so the app can access that data when it launches. Sending multiple notifications with data that is not stored on the server can be risky, because the application only receives the notification when the user opens the app from that notification, so if they tap on one notification, the app will only every receive that one.
If you have them all in a list on your server, the app can simply go and pull that list down, and process it, making sure no data is lost.