InfinityScroll.js

const React = require('react');
const EventListener = require('react/lib/EventListener');
const {shouldComponentUpdate} = require('react/lib/ReactComponentWithPureRenderMixin');

const InfinityScroll = React.createClass({
  propTypes: {
    children: React.PropTypes.node.isRequired,
    enabled: React.PropTypes.bool.isRequired,
    threshold: React.PropTypes.number.isRequired,
    onScrollDown: React.PropTypes.func.isRequired
  },
  getDefaultProps() {
    return {
      enabled: true,
      threshold: 250
    };
  },
  componentDidMount() {
    this.listener = EventListener.listen(window, 'scroll', this.onScroll);
    this.onScroll();
  },
  shouldComponentUpdate,
  componentWillUnmount() {
    this.listener.remove();
  },
  onScroll() {
    if (!this.props.enabled) {
      return;
    }

    const container = React.findDOMNode(this.refs.container);
    const containerTopPosition = this.getElementTopPosition(container);
    const scrollTop = this.getScrollTop();
    const bottomDistance = containerTopPosition + container.offsetHeight - scrollTop - window.innerHeight;
    if (bottomDistance < this.props.threshold) {
      this.props.onScrollDown();
    }
  },
  getScrollTop() {
    if (window.pageYOffset) {
      return window.pageYOffset;
    }

    return (document.documentElement || document.body.parentNode || document.body).scrollTop;
  },
  getElementTopPosition(element) {
    if (!element) {
      return 0;
    }

    return element.offsetTop + this.getElementTopPosition(element.offsetParent);
  },
  render() {
    return (
      <div ref="container">
        {this.props.children}
      </div>
    );
  }
});

module.exports = InfinityScroll;