how to call webservice after close app in ionic 2? - ionic-framework

I updated the location to my server as backgound process without open app in ionic 2 framework. I referred and tried many ways but could not achive (my desired goal). Is there any solution for this issue?

You can use the Cordova pause event to run the processes when the user switch the app or let's say run processes in background.
The pause event fires when the native platform puts the application into the background, typically when the user switches to a different application.
document.addEventListener("pause", onPause, false);
function onPause() {
// Handle the pause event
}

Related

Run methods even when the application has been closed

I have a method that works like a timer. When a certain time is reached, the app is capable of sending a push notification to the user. The problem with this is that I have only gotten this method to work when the app is running in the background or when the user is running the app.
My question is if there is any way to keep this method running even when the user has completely close the application, regardless of whether it is on Android or iOS.
if your needs to work in background then use Flutter Background Service and Put that function onStart method,
it will works while your app in Background Mode and it's not running,
https://pub.dev/packages/flutter_background_service
flutter_background_service: ^2.4.6

Flutter - background process - how best to package a process that can started in multiple ways

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.

how to open calling screen when App is killed , I am using agora.io

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

Flutter: automatically resume app from background service

Is there a way to automatically resume a flutter app from a paused or inactive lifecycle state with a background service?
Similar to when the WhatsApp app received a call while it was paused or inactive.
No, you can not simply wake up the app from a service. This would open the door for all kinds of spam apps and security risks. You need to specifically register it as VOIP app using CallKit or something like SIP on Android to receive incoming calls.
For other things you can use push notifications but that won't start your app. The user always has to click on the notification that you display.
You need to use a couple of things together:
Use push notifications to wake up your app:
https://pub.dev/packages/firebase_messaging
To start your app using push notifications refers to this post:
https://stackoverflow.com/a/48405551/4335775
Use CallKit (IOS) or ConnectionServices (Android) to show the upcoming call screen. By the day of this answer there are only a few packages to handle these things, here is one that can handle both platforms:
https://pub.dev/packages/flutter_callkeep
If you want a completely different thing and need to run some background process, there are bunch whole of things you should know first. I suggest beginning here: https://flutter.dev/docs/development/packages-and-plugins/background-processes
Here is a usefull package to work with background processes that should be constantly running:
https://pub.dev/packages/background_fetch
The app can only be waked up with explicit commands. The user must hit the button. And there are ways to handle the input, messages may pass parameters, you can save the previous state in the database or shared preferences, etc.

Is there a way by which we could run application in background in flutter?

I want to run my application in background and when the volume buttons are pressed (a specific combination) then my application would open.
Android?
There is no need to "run the application in background". What you can do is register a receiver on android.media.VOLUME_CHANGED_ACTION event and then use method channels to convey the event from the native part of the app to Flutter. However, note that android.media.VOLUME_CHANGED_ACTION is not documented and you should use it with caution.