Connection to an existing session

Since iOS SDK build 2.6.76, it is possible to connect to an existing websocket session on the server to accept an incoming call when push notification is received:

1. Set keepAlive option when conection is established for the first time

   - (FPWCSApi2Session *)connectWithOptions:(FPWCSApi2SessionOptions *)options {
       options.urlServer = _connectUrl.text;
       options.keepAlive = true;
       options.sipRegisterRequired = _sipRegRequired.control.isOn;
       options.sipLogin = _sipLogin.input.text;
       options.sipAuthenticationName = _sipAuthName.input.text;
       options.sipPassword = _sipPassword.input.text;
       options.sipDomain = _sipDomain.input.text;
       options.sipOutboundProxy = _sipOutboundProxy.input.text;
       options.sipPort = [NSNumber numberWithInteger: [_sipPort.input.text integerValue]];
       options.appKey = @"defaultApp";
       ...
       session = [FPWCSApi2 createSession:options error:&error];
       ...
       [session connect];
       return session;
   }
   

2. Keep a session token after successful connection

   [session on:kFPWCSSessionStatusEstablished callback:^(FPWCSApi2Session *rSession){
       _authToken.input.text = [rSession getAuthToken];
       [self changeConnectionStatus:[rSession getStatus]];
       [self onConnected:rSession];
       if (!_sipRegRequired.control.isOn) {
           [self changeViewState:_callButton enabled:YES];
       }
   }];
   

   Then, the session can be disconnected on mobile device when application goes to background, but the session will be kept on server during 1 hour by default.

3. When push notification is received, connect to the existing session by token

   - (FPWCSApi2Session *)connectWithToken {
       FPWCSApi2SessionOptions *options = [[FPWCSApi2SessionOptions alloc] init];
       options.authToken = _authToken.input.text;
       return [self connectWithOptions:options];
   }
   

4. Receive incoming call event and create answer/hangup alert dialog

   [session onIncomingCallCallback:^(FPWCSApi2Call *rCall) {
       call = rCall;
       ...
       alert = [UIAlertController
                alertControllerWithTitle:[NSString stringWithFormat:@"Incoming call from '%@'", [rCall getCallee]]
                message:error.localizedDescription
                preferredStyle:UIAlertControllerStyleAlert];
   
       UIAlertAction* answerButton = [UIAlertAction
                                      actionWithTitle:@"Answer"
                                      style:UIAlertActionStyleDefault
                                      handler:^(UIAlertAction * action) {
                                          [call answer];
                                      }];
   
       [alert addAction:answerButton];
       UIAlertAction* hangupButton = [UIAlertAction
                                       actionWithTitle:@"Hangup"
                                       style:UIAlertActionStyleDefault
                                       handler:^(UIAlertAction * action) {
                                           [call hangup];
                                       }];
   
       [alert addAction:hangupButton];
       [self presentViewController:alert animated:YES completion:nil];
   }];
   

5. Accept the incoming call

   [call on:kFPWCSCallStatusEstablished callback:^(FPWCSApi2Call *call){
       [self changeCallStatus:call];
       [self toHangupState];
       [self changeViewState:_holdButton enabled:YES];
   }];