Владимир

sendCommand(cmd) {
    if(cmd) {
      this.socket.write(cmd + '\u0000\r\n');
    }
    
      return new Promise((resolve, reject) => {
        const chunks = [];
        
        const handleData = chunk => {
          chunks.push(chunk);
        };

        const handleError = err => {
          reject(err);
        };

        const handleEnd => {
          const data = Buffer.concat(chunks).toString().match(/.*?\r\n/g);
          resolve(data);
        }

        this.socket.on('data', handleData);
        this.socket.on('error', handleError);
        this.socket.on('end', handleEnd);
      });
  }

class example extends React.Component {
  state = {
    data: [],
    isLoading: true,
  }

  componentDidMount() {
    fetch('example/url')
      .then(response => response.json())
      .then(data => this.setState({ data }))
  }

  render() {
    const { isLoading } = this.state

    if (isLoading) {
      return <div>Загрузка</div>
    }

    return data.map(item => <div key={item.id}>{item.name}</div>)
  }
}

data ? <КакойТоКомпонентДляОтображенияДанных data={data} /> : <Preloader />

const parseUserName = userName => userName.replace(/ (.*)$/, match => match.substr(0, 2) + '.')

parseUserName = userName => {
  const [first, last] = userName.split(' ')
  return `${first} ${last[0]}.`
}

$(window).scroll(function onScroll() {
  if ($(this).scrollTop() > 777) {
    $('.div_clone').clone().appendTo('.container2');
    $(this).off('scroll', onScroll);
  }
});