作为一个初学者，我正在玩 node.js，并试图让登录/认证运行但被卡在那里。然后我使用 npm 下载了 connect-flash 中间件，这就是我的 server.js 的样子：
var express = require('express'),
passport = require('passport'),
util = require('util'),
LocalStrategy = require('passport-local').Strategy,
wines = require('./routes/wines');
var users = [
{ id: 1, username: 'bob', password: 'secret', email: 'bob@example.com' }
, { id: 2, username: 'joe', password: 'birthday', email: 'joe@example.com' }
];
function findById(id, fn) {
var idx = id - 1;
if (users[idx]) {
fn(null, users[idx]);
} else {
fn(new Error('User ' + id + ' does not exist'));
}
}
function findByUsername(username, fn) {
for (var i = 0, len = users.length; i < len; i++) {
var user = users[i];
if (user.username === username) {
return fn(null, user);
}
}
return fn(null, null);
}
// Passport session setup.
// To support persistent login sessions, Passport needs to be able to
// serialize users into and deserialize users out of the session. Typically,
// this will be as simple as storing the user ID when serializing, and finding
// the user by ID when deserializing.
passport.serializeUser(function(user, done) {
done(null, user.id);
});
passport.deserializeUser(function(id, done) {
findById(id, function (err, user) {
done(err, user);
});
});
// Use the LocalStrategy within Passport.
// Strategies in passport require a `verify` function, which accept
// credentials (in this case, a username and password), and invoke a callback
// with a user object. In the real world, this would query a database;
// however, in this example we are using a baked-in set of users.
passport.use(new LocalStrategy(
function(username, password, done) {
// asynchronous verification, for effect...
process.nextTick(function () {
// Find the user by username. If there is no user with the given
// username, or the password is not correct, set the user to `false` to
// indicate failure and set a flash message. Otherwise, return the
// authenticated `user`.
findByUsername(username, function(err, user) {
if (err) { return done(err); }
if (!user) { return done(null, false, { message: 'Unknown user ' + username }); }
if (user.password != password) { return done(null, false, { message: 'Invalid password' }); }
return done(null, user);
})
});
}
));
var flash = require('connect-flash');
var express = require("express");
var app = express();
app.get('/', function(req, res){
res.render('index', { user: req.user });
});
app.get('/flash', function(req, res){
req.flash('info', 'Flash is back!')
res.redirect('/');
});
app.get('/account', ensureAuthenticated, function(req, res){
res.render('account', { user: req.user });
});
app.get('/login', function(req, res){
res.render('login', { user: req.user, message: "Hello!"});
});
// configure Express
app.configure(function() {
app.set('views', __dirname + '/views');
app.set('view engine', 'ejs');
app.use(express.logger());
app.use(express.cookieParser());
app.use(express.bodyParser());
app.use(express.methodOverride());
app.use(express.session({ secret: 'keyboard cat' }));
// Initialize Passport! Also use passport.session() middleware, to support
// persistent login sessions (recommended).
app.use(passport.initialize());
app.use(passport.session());
app.use(app.router);
app.use(express.cookieParser('keyboard cat'));
app.use(express.session({ cookie: { maxAge: 60000 }}));
app.use(flash());
});
// POST /login
// Use passport.authenticate() as route middleware to authenticate the
// request. If authentication fails, the user will be redirected back to the
// login page. Otherwise, the primary route function function will be called,
// which, in this example, will redirect the user to the home page.
//
// curl -v -d "username=bob&password=secret" http://127.0.0.1:3000/login
app.post('/login',
passport.authenticate('local', { failureRedirect: '/login', failureFlash: true }),
function(req, res) {
res.redirect('/');
});
app.get('/logout', function(req, res){
req.logout();
res.redirect('/');
});
app.listen(3000);
// Simple route middleware to ensure user is authenticated.
// Use this route middleware on any resource that needs to be protected. If
// the request is authenticated (typically via a persistent login session),
// the request will proceed. Otherwise, the user will be redirected to the
// login page.
function ensureAuthenticated(req, res, next) {
if (req.isAuthenticated()) { return next(); }
res.redirect('/login')
}
app.get('/wines', wines.findAll);
app.get('/wines/:id', wines.findById);
console.log('Listening on port 3000...');
为什么我仍然会收到该错误？如何解决？