CarouselItem.js

var React = require('react');
var joinClasses = require('./utils/joinClasses');
var classSet = require('./utils/classSet');
var TransitionEvents = require('./utils/TransitionEvents');

var CarouselItem = React.createClass({displayName: "CarouselItem",
  propTypes: {
    direction: React.PropTypes.oneOf(['prev', 'next']),
    onAnimateOutEnd: React.PropTypes.func,
    active: React.PropTypes.bool,
    caption: React.PropTypes.node
  },

  getInitialState: function () {
    return {
      direction: null
    };
  },

  getDefaultProps: function () {
    return {
      animation: true
    };
  },

  handleAnimateOutEnd: function () {
    if (this.props.onAnimateOutEnd && this.isMounted()) {
      this.props.onAnimateOutEnd(this.props.index);
    }
  },

  componentWillReceiveProps: function (nextProps) {
    if (this.props.active !== nextProps.active) {
      this.setState({
        direction: null
      });
    }
  },

  componentDidUpdate: function (prevProps) {
    if (!this.props.active && prevProps.active) {
      TransitionEvents.addEndEventListener(
        this.getDOMNode(),
        this.handleAnimateOutEnd
      );
    }

    if (this.props.active !== prevProps.active) {
      setTimeout(this.startAnimation, 20);
    }
  },

  startAnimation: function () {
    if (!this.isMounted()) {
      return;
    }

    this.setState({
      direction: this.props.direction === 'prev' ?
        'right' : 'left'
    });
  },

  render: function () {
    var classes = {
      item: true,
      active: (this.props.active && !this.props.animateIn) || this.props.animateOut,
      next: this.props.active && this.props.animateIn && this.props.direction === 'next',
      prev: this.props.active && this.props.animateIn && this.props.direction === 'prev'
    };

    if (this.state.direction && (this.props.animateIn || this.props.animateOut)) {
      classes[this.state.direction] = true;
    }

    return (
      React.createElement("div", React.__spread({},  this.props, {className: joinClasses(this.props.className, classSet(classes))}), 
        this.props.children, 
        this.props.caption ? this.renderCaption() : null
      )
    );
  },

  renderCaption: function () {
    return (
      React.createElement("div", {className: "carousel-caption"}, 
        this.props.caption
      )
    );
  }
});

module.exports = CarouselItem;