How to use the react-native-ble-manager.connect function in react-native-ble-manager

test(peripheral) {
    if (peripheral){
      if (peripheral.connected){
        BleManager.disconnect(peripheral.id);
      }else{
        BleManager.connect(peripheral.id).then(() => {
          let peripherals = this.state.peripherals;
          let p = peripherals.get(peripheral.id);
          if (p) {
            p.connected = true;
            peripherals.set(peripheral.id, p);
            this.setState({peripherals});
          }
          console.log('Connected to ' + peripheral.id);


          setTimeout(() => {

            /* Test read current RSSI value
            BleManager.retrieveServices(peripheral.id).then((peripheralData) => {
              console.log('Retrieved peripheral services', peripheralData);

return new Promise( (resolve, reject) =>{
            BleManager.connect(id)
                .then( (peripheralInfo) => {
                    console.log('Connected peripheralInfo: ', peripheralInfo);
	                this.peripheralId = peripheralInfo.id;
                    this.getUUID(peripheralInfo);                   
                    if(this.nofityServiceUUID.length == 4 || this.nofityServiceUUID.length != 36 ||
                        this.nofityServiceUUID == '' || this.nofityCharacteristicUUID == '' || 
                        this.writeServiceUUID == '' ||this.writeCharacteristicUUID == ''){
                            return 'invalid';
                    }
                    return BleManager.startNotification(this.peripheralId, this.nofityServiceUUID, this.nofityCharacteristicUUID)
                }).then((status) => {
                    this.isConnecting = false;   //当前蓝牙连接结束	   
                    if(status == 'invalid'){
                        console.log('Notification error');  //连接成功但不能打开通知监听            
                        // this.disconnect();  // 断开当前连接
                        reject(status);

function handleConnectPeripheral() {
      console.log("handle connect to", peripheral);
      BleManager.connect(peripheral.id).then(() => {
        setBleState("connected");
        changeCode({"type": "connect", "peripheral_id": peripheral.id});
        setTimeout(() => {

          BleManager.retrieveServices(peripheral.id).then((peripheralInfo) => {
            console.log(peripheralInfo);

            setTimeout(() => {
              BleManager.startNotification(peripheral.id, service, contentsCharacteristic).then(() => {
                console.log('Started notification on ' + peripheral.id);
                setTimeout(() => {
                  BleManager.write(peripheral.id, service, filenameCharacteristic, stringToBytes("/code.py")).then(() => {
                    console.log('Wrote filename');
                    setFileState("nameSet");
                  });

connect = (peripheral_id) => {
    BleManager.connect(peripheral_id)
      .then(() => {
        this.setState({
          connected_peripheral: peripheral_id
        });

        prompt(
          'Enter full name',
          'Enter your full name to attend',
          [
            {
              text: 'Cancel',
              onPress: () => {
                console.log('Cancel Pressed')
              }
            },
            {

return new Promise( (resolve, reject) =>{
            BleManager.connect(id)
                .then(() => {
                    console.log('Connected success.');
                    return BleManager.retrieveServices(id);                    
                })
                .then((peripheralInfo)=>{
                    console.log('Connected peripheralInfo: ', peripheralInfo);                    
                    this.peripheralId = peripheralInfo.id;
                    this.getUUID(peripheralInfo);  
                    this.isConnecting = false;   //当前蓝牙连接结束  
                    resolve(peripheralInfo);
                })
                .catch(error=>{
                    console.log('Connected error:',error);
                    this.isConnecting = false;   //当前蓝牙连接结束  
                    reject(error);
                });

componentDidMount() {
    this.handlerUpdate = bleManagerEmitter.addListener('BleManagerDidUpdateValueForCharacteristic', this.handleUpdateValueForCharacteristic );

    BleManager.connect(this.state.device_id).then(() => {
      let peripherals = this.state.peripherals;
      let p = peripherals.get(this.state.device_id);
      let id = this.state.device_id;
      if (p) {
        p.connected = true;
        peripherals.set(id, p);
        this.setState({peripherals});
      }
      console.log('Connected to ' + id);

      setTimeout(() => {
        BleManager.retrieveServices(id).then((peripheralInfo) => {
          console.log(peripheralInfo);
          var service = '4fafc201-1fb5-459e-8fcc-c5c9c331914b';
          var tareCharacteristic = 'beb5483e-36e1-4688-b7f5-ea07361b26a8';
          var loadCellCharacteristic = '4a78b8dd-a43d-46cf-9270-f6b750a717c8'; //calibrate as well

return new Promise( (resolve, reject) =>{
            BleManager.connect(id)
                .then( () => {
                    console.log('Connected');
                    return BleManager.retrieveServices(id)                  
                }).then( (peripheralInfo)=>{
                    console.log('Connected peripheralInfo: ', peripheralInfo);                    
                    this.peripheralId = peripheralInfo.id;
                    this.getUUID(peripheralInfo);                   
                    if(this.nofityServiceUUID.length == 4 || this.nofityServiceUUID.length != 36 ||
                        this.nofityServiceUUID == '' || this.nofityCharacteristicUUID == '' || 
                        this.writeServiceUUID == '' ||this.writeCharacteristicUUID == ''){
                            return 'invalid';
                    }
                    return BleManager.startNotification(this.peripheralId, this.nofityServiceUUID, this.nofityCharacteristicUUID)

                }).then((status) => {
                    this.isConnecting = false;   //当前蓝牙连接结束