application.js

var options = {
  thumbnailData: [{
    title: 'Show Courses',
    number: 12,
    header: 'Learn React',
    description: 'React is a fantastic new frontend framework. React is a fantastic new frontend framework.',
    imageUrl: 'https://facebook.github.io/react/img/logo.svg'
  }, {
    title: 'Show Courses',
    number: 25,
    header: 'Learn Gulp',
    description: 'Gulp will speed up your development workflow. Gulp will speed up your development workflow. Gulp will speed up your development workflow.',
    imageUrl: 'https://avatars0.githubusercontent.com/u/6200624?v=3&s=400'
  }, {
    title: 'Show Courses',
    number: 43,
    header: 'Learn Angular',
    description: 'Angular is a lousy framework by Google',
    imageUrl: 'http://www.w3schools.com/angular/pic_angular.jpg'
  }]
};

// React, please render this class
var element = React.createElement(ThumbnailList, options);

// React, after you render this class, please place it in my body tag
React.render(element, document.querySelector('.target'));

var Badge = React.createClass({displayName: "Badge",
  render: function() {
    return React.createElement("button", {className: "btn btn-primary", type: "button"}, 
      this.props.title, " ", React.createElement("span", {className: "badge"}, this.props.number)
    )
  }
});

var Thumbnail = require('thumbnail');

var ThumbnailList = React.createClass({displayName: "ThumbnailList",
  render: function() {
    var list = this.props.thumbnailData.map(function(thumbnailProps) {
      return React.createElement(Thumbnail, React.__spread({},  thumbnailProps))
    });

    return React.createElement("div", null, 
      list
    )
  }
});

var Thumbnail = React.createClass({displayName: "Thumbnail",
  render: function() {
    return React.createElement("div", {className: "col-sm-4 col-md-4"}, 
      React.createElement("div", {className: "thumbnail"}, 
        React.createElement("img", {src: this.props.imageUrl}), 
        React.createElement("div", {className: "caption"}, 
          React.createElement("h3", null, this.props.header), 
          React.createElement("p", null, this.props.description), 
          React.createElement("p", null, 
            React.createElement(Badge, {title: this.props.title, number: this.props.number})
          )
        )
      )
    )
  }
});