Middleware

Middleware is a function that takes req, res, next params to encapsulate HTTP functionality

• to insert middleware use app.use

Common Middleware

• body-parser
• connect.compress (gzip)
• cookie parser
• cookie-session
• express-session

csurf

• app.use(require(csurf());
• protects against cross-site request forgery (CSRF)) attacks
• must be linked after express-session

directory

• app.use(connect.directory())
• provides directory listing for static files

errorhandler

• app.use(require(errorhandler)())
• provides stack traces & error messages to the client.
• Do not use in production.

static-favicon

• serves favicon

morgan

• automated logging from all requests

method-override

• provides support for x-http-method-override request header to allow browsers to fake using HTTP methods other than GET & POST. Useful for debugging. Only needed if writting APIs.

query

• parses `querystring``
• Already comes in express

response-time

• Adds X-Response-Time header to the response (milliseconds)
• Useful for performance tunning

static

• Provides support to serve static files
• You can use it multiple times to specify multiple directories

vhost

• virtual hosts

npm i --save vhost

Edit your app file to create a subdomain

// create "admin" subdomain...this should appear
// before all your other routes
var admin = express.Router();
app.use(vhost('admin.*', admin));
// create admin routes; these can be defined anywhere
admin.get('/', function(req, res) {
  res.render('admin/home');
});
admin.get('/users', function(req, res) {
  res.render('admin/users');
});