public/index.html

<!DOCTYPE html>
<html>
  <head>
    <title>Hello React</title>
    <!-- Not present in the tutorial. Just for basic styling. -->
    <link rel="stylesheet" href="css/base.css" />
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.0/react.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/react/0.13.3/JSXTransformer.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script src="https://cdnjs.cloudflare.com/ajax/libs/marked/0.3.2/marked.min.js"></script>
  </head>
  <body>
    <div id="content"></div>
    <script type="text/jsx">
      var CommentBox = React.createClass({
        loadCommentsFromServer: function () {
          $.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)
          });
        },
        handleCommentSubmit: function (comment) {
          var comments = this.state.data;
          var newComments = comments.concat([comment]);
          this.setState({data: newComments});
          $.ajax({
            url: this.props.url,
            dataType: 'json',
            type: 'POST',
            data: comment,
            success: function (data) {
              this.setState({data: data});
            }.bind(this),
            error: function (xhr, status, err) {
              console.error(this.props.url, status, err.toString());
            }.bind(this)
          });
        },
        getInitialState: function () {
          return {data: []}
        },
        componentDidMount: function () {
          this.loadCommentsFromServer();
          setInterval(this.loadCommentsFromServer, this.props.pollInterval);
        },
        render: function () {
          return(
            <div className="commentBox">
              <h1>Comments</h1>
              <CommentList data={this.state.data} />
              <CommentForm onCommentSubmit={this.handleCommentSubmit} />
            </div>
          );
        }
      });

      var CommentList = React.createClass({
        render: function () {
          var commentNodes = this.props.data.map(function (comment) {
            return (
              <Comment author={comment.author}>
                {comment.text}
              </Comment>
            );
          });
          return (
            <div className="commentList">
              {commentNodes}
            </div>
          );
        }
      });

      var CommentForm = React.createClass({
        handleSubmit: function (e) {
          e.preventDefault();
          var author = React.findDOMNode(this.refs.author).value.trim();
          var text = React.findDOMNode(this.refs.text).value.trim();
          if (!text || !author) {
            return;
          }
          this.props.onCommentSubmit({author: author, text: text});
          React.findDOMNode(this.refs.author).value = '';
          React.findDOMNode(this.refs.text).value = '';
          return;
        },
        render: function () {
          return (
            <div className="commentForm">
              <form className="commentForm" onSubmit={this.handleSubmit}>
                <input type="text" placeholder="Your name" ref="author" />
                <input type="text" placeholder="Say something..." ref="text" />
                <input type="submit" value="Post" />
              </form>
            </div>
          );
        }
      });

      var Comment = React.createClass({
        render: function () {
          var rawMarkup = marked(this.props.children.toString(), {sanizite: true});
          return (
            <div className="comment">
              <h2 className="commentAuthor">
                {this.props.author}
              </h2>
              <span dangerouslySetInnerHTML={{__html: rawMarkup}} />
            </div>
          );
        }
      });

      React.render(
        <CommentBox url="comments.json" pollInterval={2000} />,
        document.getElementById('content')
      );
    </script>
</html>