Issue with dynamic registration on Android

[PortalShooter]

In our case, registration happens when a push notification is received (data-only push and PushKit). As soon as registration is successful, ATS initiates a call. If the call ends, the user is automatically unregistered.

The implementation on iOS works well. The app launches together with PushKit, which allows me to track whether the user answered the call or not. Problems occur only on Android. I hope for your help in that problem.

Most of the issues are related to the fact that when a push is received on Android, the main application is not actually launched — only the Firebase isolate is started. Because of this, I cannot track events such as onTerminated.

Problems I’ve encountered:

1. When receiving a push via Firebase, I perform registration, but the issue is that if the user presses “reject,” I have no way to unregister, so that the account can be registered again on the next call. I see that during Siprix initialization it is possible to set unregOnDestroy, but it seems that unregistration only happens when the app itself is closed, and at the moment of receiving the push the app is not even running. Is there any way to unregister when the user declines the call? Or perhaps to force the main app to launch when a push is received?

2. Since I receive registration information only from push notifications, it is crucial that the push is always delivered. There are no issues on iOS — PushKit is always triggered. However, on Android, the push is delivered only in the background. If the app is open, I don’t receive the push. Is there any way to fix this?

3.This is not critical, but as I understand it, there is no difference between tapping on the push notification and pressing the “answer” button — in both cases, the app simply opens.

[siprix]

1. .. if the user presses “reject,” I have no way to unregister,

Currently you can implement unregister only in the native code of CallNotifService.kt
by handling onCallTerminated and invoke unregister there.

Here is reference implementation: CallNotifService.kt.zip

To apply it:

• replace existing file in the local PubDev folder with provided one
  Windows: C:\Users\[user]\AppData\Local\Pub\Cache\hosted\pub.dev\
  MacOS: ~/.pub-cache/hosted/pub.dev/
siprix_voip_sdk_android-1.0.29\android\src\main\kotlin\com\siprix\voip_sdk\CallNotifService.kt
• build app, run, check the same case.

2. ... on Android, the push is delivered only in the background ...

If you are using data-messages they should be also received in foreground.
Try to add the same handler for 'onMessage' in Flutter code:

FirebaseMessaging.onBackgroundMessage(_firebaseMessagingHandler);
FirebaseMessaging.onMessage.listen(
        (RemoteMessage message) => _firebaseMessagingHandler(message));

See also:
https://firebase.google.com/docs/cloud-messaging/flutter/receive-messages#foreground-messages

3. ... there is no difference between tapping on the push notification and pressing the “answer” button

Yes, in both cases Activity will be opened.
But tap “answer” button also causes sending event kOnCallAcceptNotif and Flutter code accepts call.

[PortalShooter]

Hello,

1. I tried using your file, but unfortunately the behavior did not change.
   When making a second call after ending the first one, I see the following error from SiprixVoipSdkPlugin:

handleAccountAdd id:1 err:-1021 / Account with same extension@server already exists
For the call to come through again, I have to launch the app and then close it. A repeated call while the app is already active results in the same error.

2. Thank you for the tip regarding the FirebaseMessaging.onMessage method. It does work — I can handle push notifications in the foreground. However, the issue is that the notification does not appear visually. I understand that in your scenario my task is to track the call state and respond accordingly, but in our application calling is a secondary feature.

I can display an incoming call notification within the app myself, but ideally I would like to use a native implementation if possible. Is there such an option?

In the documentation you provided, I see that this can be addressed using a "High Priority" notification channel. Is it possible to configure this?

[siprix]

When making a second call after ending the first one, I see the following error from SiprixVoipSdkPlugin:
handleAccountAdd id:1 err:-1021 / Account with same extension@server already exists

Plz realize difference between 'unregister' and 'delete' account.
Unregister means sending REGISTER request with header Expire:0, which prevents app from receiving new incoming calls. But account exist (see error text), it's valid and app can use for outgoing calls or register again.
Delete - means Unregister + completely remove account.
To fix this case, modify provided CallNotifService.kt:467 from accountUnregister to accountDelete.

.. notification does not appear visually
I can display an incoming call notification within the app myself, but ideally I would like to use a native implementation if possible

Unlike the PushKit implementation, the received notification is not associated with the call. It just wakes app up and prepares for receiving call. Incoming call notification displayed only when received SIP INVITE request.
Typically, server sends INVITE just after client restores registration - on app side delay between receiving push and INVITE will be quite short.
Plz provide more details what kind of functionality are you trying to implement in this case.

[PortalShooter]

The registration issue has been resolved. All I had to do was uncomment the refreshRegistration() method to make it work.

As for the system notification.
The case is assumed to be approximately the following -

1. A data-only push arrives
2. User registration is underway
3. ATS sends a SIP Invite
4. The system call notification pops up
5. The user clicks reply/reject on this notification regardless of whether the application is in foreground or not

[siprix]

The case is assumed to be approximately the following -
...
5. The user clicks reply/reject on this notification regardless of whether the application is in foreground or not

Current plugin implementation is designed to work exactly as explained.
If you mean case: "app is in foreground; push received; notification not displayed" - it's controlled by CallNotifService.kt:485

    if (_service.shouldShowNotificationWhenInForeground() || !_service.isAppInForeground()) {
        _service.displayIncomingCallNotification(callId, accId, withVideo, hdrFrom, hdrTo)

Comment whole 'if' line if you need to display incoming call notification always (doesn't matter is app in background or foreground).
By default, notification not displayed when app is in foreground (already present on screen).

[PortalShooter]

Everything is working fine, thank you very much.
I have to deal with the last two points. —

1. Since the interaction is primarily through the system push, I need to be able to process a click on it. If the user clicks on the push or on the "reply" button, then I should be able to navigate to the call page. How can I do this?
2. Are there any plans to release the settings for android that we discussed? The fact is that when I send the project to ci/cd for assembly, I will lose all changes in the source code.
   I see that you connect this service in AndroidManifest and use it in SiprixVoipSdkPlugin. Can I connect this service in my AndroidManifest so that SiprixVoipSdkPlugin uses it?

[siprix]

1. If the user clicks ... I should be able to navigate to the call page

It's default behavior. Click notification or its 'accept' button opens Activity.
If you means case, when app has multiple pages or some internal navigation
use callback: CallsModel::onNewIncomingCall, which is triggered each time when new incoming call received.

See example app: home.dart:34 (it switches to the 'Calls' tab when call received).

2. Are there any plans to release the settings for android that we discussed?

App can create own service by extending CallNotifService, as shown on step #2 this manual

We'll add some methods in CallNotifService, which can be overridden in child class, it allows to move all newly added code there.

[siprix]

Here is updated source code, with integration changes services.zip:

• CallNotifService.kt - replace existing file in the plugin's folder. We'll publish it soon;
• MyNotifService.kt - put into your project's folder, as explained in the manual, from previous letter;

[siprix]

@PortalShooter were you able to check last provided files and integrate them into own app?

[PortalShooter]

@siprix I haven't dealt with this issue yet. I will return to this task in a few days. In any case, I'll write back to you.