From e415b632f8dad60db66832ca3816de3d0c764e06 Mon Sep 17 00:00:00 2001
From: Xu Wang <xuwang@gmail.com>
Date: Tue, 23 Feb 2016 17:13:14 -0800
Subject: [PATCH 1/2] add public/scripts/comments.js

---
 public/index.html          |   2 +-
 public/scripts/comments.js | 129 +++++++++++++++++++++++++++++++++++++
 2 files changed, 130 insertions(+), 1 deletion(-)
 create mode 100644 public/scripts/comments.js
diff --git a/public/index.html b/public/index.html
index 21340e72..07ba54f1 100644
--- a/public/index.html
+++ b/public/index.html
@@ -13,7 +13,7 @@
   </head>
   <body>
     <div id="content"></div>
-    <script type="text/babel" src="scripts/example.js"></script>
+    <script type="text/babel" src="scripts/comments.js"></script>
     <script type="text/babel">
       // To get started with this tutorial running your own code, simply remove
       // the script tag loading scripts/example.js and start writing code here.
diff --git a/public/scripts/comments.js b/public/scripts/comments.js
new file mode 100644
index 00000000..da1a625c
--- /dev/null
+++ b/public/scripts/comments.js
@@ -0,0 +1,129 @@
+/**
+ * Go through the tutorial
+ */
+
+var Comment = React.createClass({
+  rawMarkup: function() {
+    var rawMarkup = marked(this.props.children.toString(), {sanitize: true});
+    return { __html: rawMarkup };
+  },
+  render: function(){
+    return(
+      <div className="comment">
+        <h3 className="commentAuthor">
+          {this.props.author}
+        </h3>
+          <span dangerouslySetInnerHTML={this.rawMarkup()} />
+      </div>
+    );
+  }
+});
+
+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) {
+    $.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} key={comment.id}>
+          {comment.text}
+        </Comment>
+      );
+    });
+    return (
+      <div className="commentList">
+        {commentNodes}
+      </div>
+    );
+  }
+});
+
+var CommentForm = React.createClass({
+  getInitialState: function() {
+    return {author: '', text: ''};
+  },
+  handleAuthorChange: function(e) {
+    this.setState({author: e.target.value});
+  },
+  handleTextChange: function(e) {
+    this.setState({text: e.target.value});
+  },
+  handleSubmit: function(e) {
+    e.preventDefault();
+    var author = this.state.author.trim();
+    var text = this.state.text.trim();
+    if (!text || !author) {
+      return;
+    }
+    this.props.onCommentSubmit({author: author, text: text});
+    this.setState({author: '', text: ''});
+  },
+  render: function() {
+    return (
+      <form className="commentForm" onSubmit={this.handleSubmit}>
+        <input
+          type="text"
+          placeholder="Your name"
+          value={this.state.author}
+          onChange={this.handleAuthorChange}
+        />
+        <input
+          type="text"
+          placeholder="Say something..."
+          value={this.state.text}
+          onChange={this.handleTextChange}
+        />
+        <input type="submit" value="Post" />
+      </form>
+    );
+  }
+});
+
+ReactDOM.render(
+  <CommentBox url="/api/comments" pollInterval={2000} />, 
+  document.getElementById('content')
+);

From 5846f665f6452f78856afa4675099dddf0c5e266 Mon Sep 17 00:00:00 2001
From: Xu Wang <xuwang@gmail.com>
Date: Tue, 23 Feb 2016 17:33:21 -0800
Subject: [PATCH 2/2] add optimistic updates

---
 public/scripts/comments.js | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/public/scripts/comments.js b/public/scripts/comments.js
index da1a625c..f60c2cbc 100644
--- a/public/scripts/comments.js
+++ b/public/scripts/comments.js
@@ -34,6 +34,10 @@ var CommentBox = React.createClass({
     });
   },
   handleCommentSubmit: function(comment) {
+    var comments = this.state.data;
+    comment.id = Date.now();
+    var newComments = comments.concat([comment]);
+    this.setState({data: newComments});
     $.ajax({
       url: this.props.url,
       dataType: 'json',
@@ -43,6 +47,7 @@ var CommentBox = React.createClass({
         this.setState({data: data});
       }.bind(this),
       error: function(xhr, status, err) {
+        this.setState({data: comments});
         console.error(this.props.url, status, err.toString());
       }.bind(this)
     });
