Reconnection Handling

Real-world apps operate in varying network conditions and thus require handling for network bandwidth issues. The SDK provides callbacks when a user gets disconnected due to network issues or network switch and also when the user gets reconnected again.

Reconnecting & Reconnected Callbacks

onReconnecting and onReconnected callbacks are provided in HMSUpdateListener.So, These method needs to be overridden in the class wherever HMSUpdateListener is implemented.

class Meeting implements HMSUpdateListener, HMSActionResultListener{

  ...

  //OnReconnecting callback is triggered when the SDK detects a network issue or is trying to
  // reconnect automatically on a network drop, switch etc.
  @override
  void onReconnecting(){
      // Reconnecting...
      // Handle reconnection by showing loaders etc.
  }

  //OnReconnected callback is triggered when the SDK has successfully recovered from a network
  // drop, switch or a network issue etc.
  @override
  void onReconnected(){
      // Reconnected...
      // Handle by resetting the loaders and switching to normal UI.
  }

  ...
}

Case when a user never gets reconnected

SDK tries to reconnect the user automatically for 60 seconds after that the connection gets terminated and the peer is removed from the room by SDK. If reconnection fails the SDK sends onHMSError callback.

class Meeting implements HMSUpdateListener, HMSActionResultListener{

  ...

  @override
    void onHMSError({required HMSException error}){
      //Handle the UI depending on the error object
    }
}

The user will receive the following callbacks with error object having isTerminal:true and errorCode as :

• Error Code: 1003, Cause: Websocket disconnected

• Error Code: 4005, Cause: ICE Connection Failed due to network issue[PUBLISH]

• Error Code: 4005, Cause: ICE Connection Failed due to network issue[SUBSCRIBE]

Best practices to handle reconnection

The SDK will send onReconnecting callback first if the user disconnects, If the user reconnects the SDK sends onReconnected callback whereas if the user fails to connect then it sends onHMSError.These callbacks can be handled as follows:

• Once the SDK sends onReconnecting callback, Do not allow the user to interact with UI and show loaders or reconnecting indicator.
• If onReconnected is received then switch back to room UI allowing interaction as usual.
• If the user fails to reconnect then SDK sends onHMSError callback, look for errorCode parameter and if it is something(generally 1003,4005 etc.) such that the user can never reconnect and then navigate to the HomeScreen, showing a toast or errorDialog to the user with a description.