How to use

ActiveIdentifier

function

in

Characteristic

this.on('close', () => {
        this.debug('remove event listeners');

        tvService.getCharacteristic(Characteristic.Active)
          .removeListener('set', setActive);

        tvService.getCharacteristic(Characteristic.ActiveIdentifier)
          .removeListener('set', setActiveIdentifier);

        tvService.getCharacteristic(Characteristic.RemoteKey)
          .removeListener('set', setRemoteKey);

        tvService.getCharacteristic(Characteristic.PowerModeSelection)
          .removeListener('set', setPowerModeSelection);

        speakerService.getCharacteristic(Characteristic.VolumeSelector)
          .removeListener('set', setVolumeSelector);
      });

this.on('input', msg => {
        switch (msg.topic) {
          case 'InputSource': {
            let identifier = msg.payload;
            if (typeof msg.payload === 'string') {
              config.inputsources.forEach((src, i) => {
                if (msg.payload === src.name) {
                  identifier = i + 1;
                }
              });
            }

            if (config.inputsources[identifier - 1]) {
              this.debug('set ActiveIdentifier ' + identifier + ' (payload was ' + msg.payload + ')');
              this.status({shape: 'dot', fill: 'blue', text: config.inputsources[identifier - 1].name});
              tvService.updateCharacteristic(Characteristic.ActiveIdentifier, identifier);
            }

            break;
          }

          default:
            this.debug('set Active ' + msg.payload);
            this.status({shape: msg.payload ? 'dot' : 'ring', fill: msg.payload ? 'blue' : 'grey'});
            tvService.updateCharacteristic(Characteristic.Active, msg.payload ? 1 : 0);
        }
      });