Goodday
我正在关注[this]（https://www.youtube.com/watch?v=iX8UhDOmkPE&t=682s“登录并认证应用”）教程。一个区别是我使用的是MySQL而不是猫鼬。
在尝试登录时，我要刷新消息。例如“未知的用户名”。
不幸的是，这种情况没有发生，并且在模块通行证中硬编码的消息“凭据丢失”也不起作用。
server.js
// modules required here
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookiesParser());
app.use(session({
secret: 'pussycat',
saveUninitialized: true,
resave: true
}));
// Express Validator
app.use(expressValidator({
errorFormatter: function (param, msg, value) {
var namespace = param.split('.')
, root = namespace.shift()
, formParam = root;
while (namespace.length) {
formParam += '[' + namespace.shift() + ']';
}
return {
param: formParam,
msg: msg,
value: value
};
},
customValidators: {
myCustomFunc: function (value) {
return false;
}
}
}));
/**
* Create server
*/
http.createServer(app).listen(port);
console.log("Server listening on port " + port);
/**
* Connect to database
*/
var connection = mysql.createConnection({
host: "localhost",
user: "root",
password: "*****",
database: '********'
});
/**
* Print out if the connection was succesful
*/
connection.connect(function (error) {
if (!!error) {
console.log("Error occured while connecting to database");
}
else {
console.log("Connected to Database!");
}
});
/**
* Serve pages and set default directory
*/
app.use(express.static(__dirname + './../client/'));
/**
* The views to switch between on the webpage
*/
app.set("views", path.join(__dirname + './../client/views'));
/**
* set handlebars as template view engine
*/
app.engine('handlebars', exphbs({ defaultLayout: '../../../client/views/layouts/loginLayout' }));
app.set("view engine", "handlebars");
// make sure initialize is below serving pages and setting a default directory
app.use(passport.initialize());
app.use(passport.session());
app.use(flash());
// Global Vars
app.use(function (req, res, next) {
res.locals.success_msg = req.flash('success_msg');
res.locals.error_msg = req.flash('error_msg');
res.locals.error = req.flash('error');
res.locals.user = req.user || null;
next();
});
/**
* routes used for redirecting the user
*/
const routesHTML = require('./modules/Routes').htmlRoutes(app);
/**
* functionality of logging in
*/
const login = require("./modules/Login").login(app, connection);
/**
* Require functionality to register and create an account
*/
const register = require('./modules/Register').register(app, connection);
登录模块
// require modeles here
module.exports.login = function (app, connection) {
passport.use(new LocalStrategy({
usernameField: 'usernameOrEmail', // set default to usernameOrEmail because thats how it is called client side
},
function (username, password, done) {
var usernamePromise = User.checkUsername(connection, username);
var emailPromise = User.checkEmail(connection, username);
Promise.all([emailPromise, usernamePromise]).then(function (values) {
// check if usernameOrEmail is known mail or known username
if (!values[0] && !values[1]) {
console.log("should thorw error message email unknown");;
return done(null, false, { message: 'Unknown mail or username' }); // <-- does not show client side
}
// create promise to retrieve user from database
var userPromise = User.getUserByUserNameOrEmail(connection, username);
Promise.all([userPromise]).then(function (user) {
// enctrypt password and compare
bcrypt.compare(password, user[0].password, function (err, result) {
if (!!err) {
console.log("Error occured when comparing the decrypted passwords");
return done(err, false, { message: 'Error occured when comparing the decrypted passwords' });
}
else if (result) {
console.log("user succesfully logged in");
// Everything seems to be OK!
return done(null, user[0]);
}
else {
console.log("password is not correct");
return done(null, false, { message: 'Invalid password' });
}
});
});
});
})
);
passport.serializeUser(function (user, done) {
done(null, user.id);
});
passport.deserializeUser(function (id, done) {
var userPromise = User.getUserById(connection, id);
Promise.all([userPromise]).then(function (user) {
if(user) {
done(null, user);
}
else {
done(null, false, { message: 'No user found with this user id'
});
}
});
app.post('/login',
passport.authenticate('local', { successRedirect: '/', failureRedirect: '/login', failureFlash: true }),
function (req, res) {
console.log("this code is reachable.."); // so far not executed yet
res.redirect('/');
});
} // <-- closes the " module.exports.login = function (app, connection) { "
我的客户端正在使用.handlebars文件：
{{#if success_msg}}
<div class="alert alert-success">{{success_msg}}</div>
{{/if}}
{{#if errors}} {{#each errors}}
<div class="alert alert-danger">{{msg}}</div>
{{/each}} {{/if}}
[编辑] 经过一天的反复试验，我终于找到了一种刷新信息的方法：）
通过添加以下内容通过本地策略中的要求：
passReqToCallback: true
这允许req.flash（'error_msg'，'用户名或电子邮件未知'）; 1
return done(null, false, req.flash('error_msg', 'Username or email not known'));
因为在server.js中，我拥有：
app.use(function (req, res, next) {
res.locals.success_msg = req.flash('success_msg');
res.locals.error_msg = req.flash('error_msg');
res.locals.error = req.flash('error');
res.locals.user = req.user || null;
next();
});
“用户名或电子邮件未知”消息在浏览器中显示为客户端
{{#if error_msg}}
<div class="alert alert-danger">{{err_msg}}</div>
{{/if}}
答案 0 :(得分：1)
您的中间件集res.locals.error：
res.locals.error = req.flash('error');
但是您的模板使用errors：
{{#if errors}} {{#each errors}}
<div class="alert alert-danger">{{msg}}</div>
{{/each}} {{/if}}
请注意，单数error和复数errors之间不匹配。
此外，我想知道{{msg}}是否不应该是{{this}}。