[example] Add Express session parsing example

karatheodory · lpinca · commit 72cf8bee2dcd · 2017-02-14T12:37:11.000+01:00
diff --git a/examples/express-session-parse/index.js b/examples/express-session-parse/index.js
@@ -0,0 +1,80 @@
+'use strict';
+
+const session = require('express-session');
+const express = require('express');
+const http = require('http');
+const uuid = require('uuid');
+
+const WebSocket = require('../..');
+
+const app = express();
+
+//
+// We need the same instance of the session parser in express and
+// WebSocket server.
+//
+const sessionParser = session({
+  saveUninitialized: false,
+  secret: '$eCuRiTy',
+  resave: false
+});
+
+//
+// Serve static files from the 'public' folder.
+//
+app.use(express.static('public'));
+app.use(sessionParser);
+
+app.post('/login', (req, res) => {
+  //
+  // "Log in" user and set userId to session.
+  //
+  const id = uuid.v4();
+
+  console.log(`Updating session for user ${id}`);
+  req.session.userId = id;
+  res.send({ result: 'OK', message: 'Session updated' });
+});
+
+app.delete('/logout', (request, response) => {
+  console.log('Destroying session');
+  request.session.destroy();
+  response.send({ result: 'OK', message: 'Session destroyed' });
+});
+
+//
+// Create HTTP server by ourselves.
+//
+const server = http.createServer(app);
+
+const wss = new WebSocket.Server({
+  verifyClient: (info, done) => {
+    console.log('Parsing session from request...');
+    sessionParser(info.req, {}, () => {
+      console.log('Session is parsed!');
+
+      //
+      // We can reject the connection by returning false to done(). For example,
+      // reject here if user is unknown.
+      //
+      done(info.req.session.userId);
+    });
+  },
+  server
+});
+
+wss.on('connection', (ws) => {
+  ws.on('message', (message) => {
+    const session = ws.upgradeReq.session;
+
+    //
+    // Here we can now use session parameters.
+    //
+    console.log(`WS message ${message} from user ${session.userId}`);
+  });
+});
+
+//
+// Start the server.
+//
+server.listen(8080, () => console.log('Listening on http://localhost:8080'));
diff --git a/examples/express-session-parse/package.json b/examples/express-session-parse/package.json
@@ -0,0 +1,11 @@
+{
+  "author": "",
+  "name": "express-session-parse",
+  "version": "0.0.0",
+  "repository": "websockets/ws",
+  "dependencies": {
+    "express": "~4.14.1",
+    "express-session": "~1.15.1",
+    "uuid": "~3.0.1"
+  }
+}
diff --git a/examples/express-session-parse/public/app.js b/examples/express-session-parse/public/app.js
@@ -0,0 +1,46 @@
+/* global fetch, WebSocket, location */
+(() => {
+  const messages = document.querySelector('#messages');
+  const wsButton = document.querySelector('#wsButton');
+  const logout = document.querySelector('#logout');
+  const login = document.querySelector('#login');
+
+  const showMessage = (message) => {
+    messages.textContent += `\n${message}`;
+    messages.scrollTop = messages.scrollHeight;
+  };
+
+  const handleResponse = (response) => {
+    return response.ok
+      ? response.json().then((data) => JSON.stringify(data, null, 2))
+      : Promise.reject(new Error('Unexpected response'));
+  };
+
+  login.onclick = () => {
+    fetch('/login', { method: 'POST', credentials: 'same-origin' })
+      .then(handleResponse)
+      .then(showMessage)
+      .catch((err) => showMessage(err.message));
+  };
+
+  logout.onclick = () => {
+    fetch('/logout', { method: 'DELETE', credentials: 'same-origin' })
+      .then(handleResponse)
+      .then(showMessage)
+      .catch((err) => showMessage(err.message));
+  };
+
+  let ws;
+
+  wsButton.onclick = () => {
+    if (ws) {
+      ws.onerror = ws.onopen = ws.onclose = null;
+      ws.close();
+    }
+
+    ws = new WebSocket(`ws://${location.host}`);
+    ws.onerror = () => showMessage('WebSocket error');
+    ws.onopen = () => showMessage('WebSocket connection established');
+    ws.onclose = () => showMessage('WebSocket connection closed');
+  };
+})();
diff --git a/examples/express-session-parse/public/index.html b/examples/express-session-parse/public/index.html
@@ -0,0 +1,21 @@
+<!DOCTYPE html>
+<html lang="en">
+  <head>
+      <meta charset="utf-8">
+      <title>Express session demo</title>
+  </head>
+  <body>
+    <h1>Choose an action.</h1>
+    <button id="login" type="button" title="Simulate login">
+      Simulate login
+    </button>
+    <button id="logout" type="button" title="Simulate logout">
+      Simulate logout
+    </button>
+    <button id="wsButton" type="button" title="Open WebSocket connection">
+      Open WebSocket connection
+    </button>
+    <pre id="messages" style="height: 400px; overflow: scroll"></pre>
+    <script src="app.js"></script>
+  </body>
+</html>
