title: Getting TypeError: this.props is undefined on ReactJs
body: <p>I am trying to do the tutorial: <a href="https://facebook.github.io/react/docs/tutorial.html" rel="noreferrer">https://facebook.github.io/react/docs/tutorial.html</a></p>
  
  <pre><code>import React, { PropTypes } from 'react';
  import classnames from 'classnames';
  import styles from './CommentBox.css';
  import withStyles from '../../decorators/withStyles';
  import Link from '../../utils/Link';
  import $ from 'jquery';
  
  @withStyles(styles)
  class CommentBox extends React.Component {
  
      constructor() {
          super();
          this.state = {data: []};
      }
  
      loadCommentsFromServer() {
          $.ajax({
              url: this.props.url,
              dataType: 'json',
              cache: false,
              success: function(data) {
                  this.setState({data: data});
              }.bind(this),
              error: function(xhr, status, err) {
                  console.error(this.props.url, status, err.toString());
              }.bind(this)
          })
      }
  
      componentDidMount() {
          this.loadCommentsFromServer();
          setInterval(this.loadCommentsFromServer, this.props.pollInterval);
      }
  
      render() {
  
          let url="/public/comments.json"
  
          return (
              &lt;div className="commentBox"&gt;
                  &lt;h1&gt;Comments&lt;/h1&gt;
                  &lt;CommentList data={this.state.data} /&gt;
                  &lt;CommentForm /&gt;
              &lt;/div&gt;
          );
      }
  
  }
  
  class CommentList extends React.Component {
  
      render() {
  
          let data = this.props.data
  
          var commentNodes = data.map(function (comment) {
            return (
              &lt;Comment author={comment.author}&gt;
                {comment.text}
              &lt;/Comment&gt;
            );
          });
  
          return (
            &lt;div className="commentList"&gt;
              {commentNodes}
            &lt;/div&gt;
          );
      }
  };
  
  class Comment extends React.Component {
      render() {
          return(
              &lt;div className="comment"&gt;
              &lt;h2 className="commentAuthor"&gt;
                {this.props.author}
              &lt;/h2&gt;
              {this.props.children}
            &lt;/div&gt;
          );
      }
  }
  
  class CommentForm extends React.Component {
    render() {
      return (
        &lt;div className="commentForm"&gt;
          Hello, world! I am a CommentForm.
        &lt;/div&gt;
      );
    }
  };
  
  export default CommentBox;
  </code></pre>
  
  <p>However, the tutorial is a bit outdated and I am using React 0.14-rc1 with ES6 syntax. I have tried my best to follow the tutorial and implementing it the 0.14 way. Was able to get to this point but now getting the error:</p>
  
  <pre><code>TypeError: this.props is undefined
  </code></pre>
  
  <p>Could not figure out the issue. Any idea why? Thanks</p>