I have a question about how best to structure a background process in a Flutter mobile app that can be triggered in a number of ways.
This background process has to run a web API call, or series of web API calls. The process will take 1 to 5 seconds to complete.
I want the process to be initiated when any of the following occurs:
When the app first starts
When the user initiates a 'refresh' by clicking on a button in the UI
Every hour
Any suggestions on how to structure this in a Flutter app?
You should take a look at this package: https://pub.dev/packages/flutter_background_service
It can run code in background and/or in foreground either on iOs and Android.
Background and foreground are run in isolate, so you should use mechanism provide by package to exchange data between your application and background/foreground.
Related
I am trying to create a flutter app that sends notification every time there is new entry in stream builder, it works fine when the app is on or opened but I want it to work and receive notification even when it is not opened , I have used workmanager to make the task work in background but it is not working ...the code for it can be found here code
Flutter apps by nature are supposed to run on a UI thread or foreground. The background tasks you are asking for are features disclosed by each individual platforms.
In case of Android, you can create a a Background Service to accomplish the tasks you need to perform when application is closed. The link to the bacground service is as follows: Creating a Background Service
In case of iOS, see this link for creating a background task. Other platform implementation will be as like above, so please have a look into each platform specific background process.
UPDATE:
Please have a look into the package Flutter Background Service. This package helps to deal with background tasks setup from flutter side even when app is closed.
NOTE:
Q: Why the service not started automatically?
A: Some android device manufacturers have a custom android os for example MIUI from Xiaomi. You have to deal with that policy.
Q: Service killed by system and not respawn?
A: Try to disable battery optimization for your app.
Actually I was trying to implement background process (fetch data from api) even the app is terminated in my flutter project how can I achieve in both Android & iOS platforms.
Have you ever wanted to execute Dart code in the background—even if your app wasn’t the currently active app?
The mechanism for this feature involves setting up an isolate.
Isolates are Dart’s model for multithreading, though an isolate
differs from a conventional thread in that it doesn’t share memory
with the main program. You’ll set up your isolate for background
execution using callbacks and a callback dispatcher.
Example
but if you want do that when app terminated, you will have to wakeup app through Workmanager or some another approach like sending firebase push notification or wakeup app in scheduled time with flutter alarm manager or something like that
I am using agora_rtc_engine for video calling.
I have tested the Firebase background message but the documentation mentions:
Since the handler runs in its own isolate outside your applications
context, it is not possible to update application state or execute any
UI impacting logic. You can however perform logic such as HTTP
requests, IO operations (updating local storage), communicate with
other plugins etc.
Source https://firebase.flutter.dev/docs/messaging/usage/
How I can display incoming call screen when Firebase notification arrived in the background when App is killed?
I also use callkeep. It shows phone's default calling screen but when I click on answer call it starts the call. I am not able to navigate to specific screen.
Thanks.
Here is something that you can try - using the CallKeepPerformAnswerCallAction event you can bring your app to foreground using bringtoforeground
This question is about the flutter framework.
I am looking for information about how to schedule background tasks in the app while the app is being used by the user. It is not necessary to run the task also when the whole app is in the background / closed.
To explain, an example:
User starts the app and goes to a news article. The page is finished rendering and the user starts reading. While the user is reading I want the app to do tasks in the background such as checking whether there is new data that can be written to the database or maybe that avatar's from other user have update and it should be updated on the user's phone.
Does anybody know where to look for this?
If it's a simple task, you may use Timer:
https://api.flutter.dev/flutter/dart-async/Timer-class.html
But it can't broadcast messages, so you should either use a provider or if it's time-critical and it's a heavy task you should use isolates:
https://api.flutter.dev/flutter/dart-isolate/Isolate-class.html
If you are unfamiliar with isolates you can use ready-made packages, like this one : https://pub.dev/packages/flutter_isolate
Is it possible to use connectivity plugin in background process?
I don't know how to call dart code in background there is little about this in docs.
I need this functionality to sync offline data with backend whenever there is a connection wether app is in foreground or background and app is in killed state like the way Whatsapp syncs messages.
You can use existing plugins for background execution (on android & ios usually in a roughly 15 minute interval)
https://pub.dev/packages/background_fetch
There is also a article dedicated to using isolates for background executions
https://flutter.dev/docs/development/packages-and-plugins/background-processes
https://medium.com/flutter/executing-dart-in-the-background-with-flutter-plugins-and-geofencing-2b3e40a1a124