Implementing VoIP call notifications in React Native for iOS when the app is in the background or killed state requires using Firebase Cloud Messaging (FCM) along with Apple's CallKit and PushKit frameworks. This allows you to receive incoming VoIP push notifications and handle them appropriately to show a native call screen.
Here's a high-level overview of the steps you need to take:
Set up Firebase Cloud Messaging (FCM): Follow Firebase's documentation to set up FCM in your React Native app for iOS. This involves configuring your Firebase project, integrating the FCM SDK, and handling the registration token.
Implement CallKit and PushKit: CallKit is used to display the native call UI, and PushKit is used to receive VoIP push notifications. To use these frameworks, you'll need to write some native code in Objective-C or Swift. You can do this by creating a custom React Native module.
- Implement CallKit to show the native call UI when the VoIP call notification is received. You'll need to handle call actions such as answering, declining, or ending the call.
- Implement PushKit to receive VoIP push notifications. This requires handling the PushKit delegate methods in your native code.
Handle FCM Notifications: When a VoIP push notification is received through FCM, you'll need to process it and trigger the CallKit UI. In your native module, handle the FCM notifications, extract the call-related information, and display the CallKit UI.
Handle Background and Killed State: To handle VoIP calls when the app is in the background or killed state, you'll need to use the PushKit delegate methods to start your app when a VoIP notification arrives.
VoIP Background Modes: In Xcode, enable the VoIP background mode for your app to allow it to receive VoIP push notifications and handle calls in the background or when killed.
Testing and Debugging: Test the VoIP call notification functionality thoroughly in different scenarios to ensure it works as expected. Use debugging tools and logs to identify and resolve any issues.
Please note that implementing VoIP call notifications in React Native with background and killed state handling is a complex task that involves both React Native and native code. It's essential to have a good understanding of both platforms and the corresponding frameworks (FCM, CallKit, PushKit) to achieve a successful implementation.
As this is a broad topic, I recommend referring to official documentation and guides for FCM, CallKit, and PushKit, as well as tutorials or examples specific to React Native VoIP call notifications.