Timer.js

/**
 * Created by tdzl2003 on 12/17/16.
 */

import React, { Component } from 'react';
import PropTypes from 'prop-types';

export default class Timer extends Component {
  static propTypes = {
    interval: PropTypes.number,
    onTimer: PropTypes.func,
    children: PropTypes.element,
  };
  componentDidMount() {
    const { interval } = this.props;
    this.timer = setInterval(this.onEvent, interval);
  }
  componentDidUpdate(prevProps) {
    if (prevProps.interval !== this.props.interval) {
      clearInterval(this.timer);
      this.timer = setInterval(this.onEvent, this.props.interval);
    }
  }
  componentWillUnmount() {
    clearInterval(this.timer);
  }
  onEvent = ev => {
    const { onTimer } = this.props;
    onTimer && onTimer(ev);
  };
  render() {
    return this.props.children || null;
  }
}