learning express step(九)

router-level middleware works in the same way as application-level middleware, except it is bound to an instance of  express.Router().

code: 

var express = require('express');
var app = express();
var router = express.Router();

// a middleware function with no mount path. This code is executed for every request to the router
router.use(function (req, res, next) {
    console.log('Time:', Date.now());
    next()
});

// a middleware sub-stack shows request info for any type of HTTP request to the /user/:id path
router.use('/user/:id', function (req, res, next) {
    console.log('Request URL:', req.originalUrl);
    next()
}, function (req, res, next) {
    console.log('Request Type:', req.method);
    next()
});

// a middleware sub-stack that handles GET requests to the /user/:id path
router.get('/user/:id', function (req, res, next) {
    // if the user ID is 0, skip to the next router
    if (req.params.id === '0') next('route');
    // otherwise pass control to the next middleware function in this stack
    else next()
}, function (req, res, next) {
    // render a regular page
    res.send('regular');
});

// handler for the /user/:id path, which renders a special page
router.get('/user/:id', function (req, res, next) {
    console.log(req.params.id);
    res.send('special');
});

app.set('view engine','jade');
// mount the router on the app
app.use('/', router);

app.listen(3000);

result: