Add support for server-side rendering Top Stories & Comments (#47)

* index.ejs: set base href to fix asset paths for SSR views

* package.json: add object-assign shim

* App.js: support prebooted HTML / hydration of content

* Adds hn-server-fetch using unofficial Firebase API

The official Firebase API (https://github.com/HackerNews/API) requires
multiple network
connections to be made in order to fetch the list of Top Stories
(indices) and then the
summary content of these stories. Directly requesting these resources
makes server-side
rendering cumbersome as it is slow and ultimately requires that you
maintain your own
cache to ensure full server renders are efficient.

To work around this problem, we can use one of the unofficial Hacker
News APIs, specifically
https://github.com/cheeaun/node-hnapi which directly returns the Top
Stories and can cache
responses for 10 minutes. In ReactHN, we can use the unofficial API for
a static server-side
render and then 'hydrate' this once our components have mounted to
display the real-time
experience.

The benefit of this is clients loading up the app that are on flakey
networks (or lie-fi)
can still get a fast render of content before the rest of our
JavaScript bundle is loaded.

* server.js: add support for SSR render of top stories and comments

* hn-server-fetch: add support for SSR nested comments

* hn-server-fetch: remove duplicate time indication

* Stories.js: display spinner for pages > 0

hn-server-fetch.js

@@ -0,0 +1,100 @@
+require('isomorphic-fetch')
+
+/*
+The official Firebase API (https://github.com/HackerNews/API) requires multiple network
+connections to be made in order to fetch the list of Top Stories (indices) and then the
+summary content of these stories. Directly requesting these resources makes server-side
+rendering cumbersome as it is slow and ultimately requires that you maintain your own 
+cache to ensure full server renders are efficient. 
+
+To work around this problem, we can use one of the unofficial Hacker News APIs, specifically
+https://github.com/cheeaun/node-hnapi which directly returns the Top Stories and can cache 
+responses for 10 minutes. In ReactHN, we can use the unofficial API for a static server-side
+render and then 'hydrate' this once our components have mounted to display the real-time 
+experience. 
+
+The benefit of this is clients loading up the app that are on flakey networks (or lie-fi)
+can still get a fast render of content before the rest of our JavaScript bundle is loaded.
+ */
+
+/**
+ * Fetch top stories
+ */
+exports.fetchNews = function(page) {
+	page = page || ''
+	return fetch('http://node-hnapi.herokuapp.com/news' + page).then(function(response) {
+	  return response.json()
+	}).then(function(json) {
+	  var stories = '<ol class="Items__list" start="1">'
+	  json.forEach(function(data, index) {
+	      var story = '<li class="ListItem" style="margin-bottom: 16px;">' +
+	          '<div class="Item__title" style="font-size: 18px;"><a href="' + data.url + '">' + data.title + '</a> ' +
+	          '<span class="Item__host">(' + data.domain + ')</span></div>' +
+	          '<div class="Item__meta"><span class="Item__score">' + data.points + ' points</span> ' +
+	          '<span class="Item__by">by <a href="https://news.ycombinator.com/user?id=' + data.user + '">' + data.user + '</a></span> ' +
+	          '<time class="Item__time">' + data.time_ago + ' </time> | ' +
+	          '<a href="/news/story/' + data.id + '">' + data.comments_count + ' comments</a></div>'
+	      '</li>'
+	      stories += story
+	  })
+	  stories += '</ol>'
+	  return stories
+	})		
+}
+
+function renderNestedComment(data) {
+	return '<div class="Comment__kids">' +
+		        '<div class="Comment Comment--level1">' +
+		            '<div class="Comment__content">' +
+		                '<div class="Comment__meta"><span class="Comment__collapse" tabindex="0">[–]</span> ' +
+		                    '<a class="Comment__user" href="#/user/' + data.user + '">' + data.user + '</a> ' +
+		                    '<time>' + data.time_ago + '</time> ' +
+		                    '<a href="#/comment/' + data.id + '">link</a></div> ' +
+		                '<div class="Comment__text">' +
+		                    '<div>' + data.content +'</div> ' +
+		                    '<p><a href="https://news.ycombinator.com/reply?id=' + data.id + '">reply</a></p>' +
+		                '</div>' +
+		            '</div>' +
+		        '</div>' +
+		    '</div>'
+}
+
+function generateNestedCommentString(data) {
+	var output = ''
+	data.comments.forEach(function(comment) {
+		output+= renderNestedComment(comment)
+		if (comment.comments) {
+			output+= generateNestedCommentString(comment)
+		} 
+	})
+	return output
+}
+
+/**
+ * Fetch details of the story/post/item with (nested) comments
+ * TODO: Add article summary at top of nested comment thread
+ */
+exports.fetchItem = function(itemId) {
+	return fetch('https://node-hnapi.herokuapp.com/item/' + itemId).then(function(response) {
+		return response.json()
+	}).then(function(json) {
+		var comments = ''
+		json.comments.forEach(function(data, index) {
+			var comment = '<div class="Item__kids">' + 
+			'<div class="Comment Comment--level0">' +
+		    '<div class="Comment__content">' +
+		        '<div class="Comment__meta"><span class="Comment__collapse" tabindex="0">[–]</span> ' +
+		            '<a class="Comment__user" href="#/user/' + data.user + '">' + data.user + '</a> ' +
+		            '<time>' + data.time_ago + '</time> ' +
+		            '<a href="#/comment/' + data.id + '">link</a></div> ' +
+		        '<div class="Comment__text">' +
+		            '<div>' + data.content +'</div> ' + 
+		            '<p><a href="https://news.ycombinator.com/reply?id=' + data.id + '">reply</a></p>' +
+		        '</div>' +
+		    '</div>' +
+		   '</div>'
+			comments += generateNestedCommentString(data) + '</div>' + comment
+		})
+		return comments
+	})
+}

package.json

@@ -24,22 +24,23 @@
   "main": "server.js",
   "dependencies": {
     "ejs": "^2.4.1",
+    "eslint-config-jonnybuchanan": "2.0.3",
     "events": "1.1.0",
     "express": "^4.13.4",
     "firebase": "2.4.2",
     "history": "2.1.1",
     "isomorphic-fetch": "^2.2.1",
+    "nwb": "0.8.1",
+    "object-assign": "^4.1.0",
     "react": "15.0.2",
     "react-dom": "15.0.2",
     "react-router": "2.4.0",
     "react-timeago": "3.0.0",
     "reactfire": "0.7.0",
     "scroll-behavior": "0.5.0",
     "setimmediate": "1.0.4",
-    "url-parse": "^1.1.1",
-    "eslint-config-jonnybuchanan": "2.0.3",
-    "nwb": "0.8.1",
     "sw-precache": "^3.1.1",
-    "sw-toolbox": "^3.1.1"
+    "sw-toolbox": "^3.1.1",
+    "url-parse": "^1.1.1"
   }
 }

server.js

@@ -2,6 +2,8 @@ var express = require('express')
 var React = require('react')
 var renderToString = require('react-dom/server').renderToString
 var ReactRouter = require('react-router')
+var objectAssign = require('object-assign')
+var HNServerFetch = require('./hn-server-fetch')
 
 require('babel/register')
 var routes = require('./src/routes')
@@ -12,6 +14,47 @@ app.set('views', process.cwd() + '/src/views')
 app.set('port', (process.env.PORT || 5000))
 app.use(express.static('public'))
 
+
+app.get(['/', '/news'], function(req, res) {
+  ReactRouter.match({
+    routes: routes,
+    location: req.url
+  }, function(err, redirectLocation, props) {
+    if (err) {
+      res.status(500).send(err.message)
+    }
+    else if (redirectLocation) {
+      res.redirect(302, redirectLocation.pathname + redirectLocation.search)
+    }
+    else if (props) {
+      HNServerFetch.fetchNews().then(function(stories) {
+        objectAssign(props.params, { prebootHTML: stories })
+        var markup = renderToString(React.createElement(ReactRouter.RouterContext, props, null))
+        res.render('index', { markup: markup })
+      })
+    }
+    else {
+      res.sendStatus(404)
+    }
+  })
+})
+
+app.get('/news/story/:id', function (req, res, next) {
+  var storyId = req.params.id
+  ReactRouter.match({
+    routes: routes,
+    location: req.url
+  }, function(err, redirectLocation, props) {
+    if (storyId) {
+      HNServerFetch.fetchItem(storyId).then(function(comments) {
+          objectAssign(props.params, { prebootHTML: comments })
+          var markup = renderToString(React.createElement(ReactRouter.RouterContext, props, null))
+          res.render('index', { markup: markup })
+      })
+    }
+  })  
+});
+
 app.get('*', function(req, res) {
   ReactRouter.match({
     routes: routes,
@@ -24,10 +67,8 @@ app.get('*', function(req, res) {
       res.redirect(302, redirectLocation.pathname + redirectLocation.search)
     }
     else if (props) {
-      var markup = renderToString(
-        React.createElement(ReactRouter.RouterContext, props, null)
-      )
-      res.render('index', { markup: markup })
+      var markup = renderToString(React.createElement(ReactRouter.RouterContext, props, null))
+      res.render('index', { markup: markup })        
     }
     else {
       res.sendStatus(404)

src/App.js

@@ -10,7 +10,9 @@ var SettingsStore = require('./stores/SettingsStore')
 var App = React.createClass({
   getInitialState() {
     return {
-      showSettings: false
+      showSettings: false,
+      showChildren: false,
+      prebootHTML: this.props.params.prebootHTML
     }
   },
 
@@ -22,6 +24,11 @@ var App = React.createClass({
     window.addEventListener('beforeunload', this.handleBeforeUnload)
   },
 
+  componentDidMount() {
+    // Empty the prebooted HTML and hydrate using live results from Firebase
+    this.setState({ prebootHTML: '', showChildren: true })
+  },
+
   componentWillUnmount() {
     if (typeof window === 'undefined') return
     window.removeEventListener('beforeunload', this.handleBeforeUnload)
@@ -58,7 +65,8 @@ var App = React.createClass({
         {this.state.showSettings && <Settings key="settings"/>}
       </div>
       <div className="App__content">
-        {this.props.children}
+        <div dangerouslySetInnerHTML={{ __html: this.state.prebootHTML }}/>
+        {this.state.showChildren ? this.props.children : ''}
       </div>
       <div className="App__footer">
         <a href="https://github.com/insin/react-hn">insin/react-hn</a>

src/Stories.js

@@ -67,7 +67,7 @@ var Stories = React.createClass({
 
     // Display a list of placeholder items while we're waiting for the initial
     // list of story ids to load from Firebase.
-    if (this.state.stories.length === 0 && this.state.ids.length === 0) {
+    if (this.state.stories.length === 0 && this.state.ids.length === 0 && this.getPageNumber() > 0) {
       var dummyItems = []
       for (var i = page.startIndex; i < page.endIndex; i++) {
         dummyItems.push(

src/views/index.ejs

@@ -29,7 +29,7 @@
     <meta name="msapplication-TileColor" content="#222222">
     <meta name="msapplication-TileImage" content="img/mstile-144x144.png">
     <meta name="msapplication-config" content="img/browserconfig.xml">
-
+    <base href="/">
     <link rel="stylesheet" href="css/style.css">
   </head>
   <body>