req.flash 不是函数 Nodejs

Question

过去一个小时我一直盯着这段代码，但我不知道如何解决这个问题，我正在 'TypeError: req.flash is not a function。我试过移动 app.use(flash)，但仍然出现错误。我该如何解决这个问题？

var flash = require('connect-flash');
var express = require('express');
var path = require('path');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var handlebars = require('express-handlebars').create({
      layoutsDir: path.join(__dirname, "views/layouts"),
      partialsDir: path.join(__dirname, "views/partials"),
      defaultLayout: 'layout',
      extname: 'handlebars'
});
var expressValidator = require('express-validator');
var session = require('express-session');
var passport = require('passport');
var localStrategy = require('passport-local').strategy;
var mongo = require('mongodb');
var mongoose = require('mongoose');
mongoose.connect('mongodb://localhost/login');
var db = mongoose.connection;

// init app
var app = express();

var routes = require('./routes/index');
var users = require('./routes/users');

// view engine
app.engine('handlebars', handlebars.engine);
app.set('view engine', 'handlebars');
app.set('views', path.join(__dirname, "views"));

app.use(expressValidator());

// bodyParser Middleware
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));
app.use(cookieParser());

// set static folder
app.use(express.static(path.join(__dirname, 'public')));
app.use('/', routes);
app.use('/users', users);

app.use(flash);

// express session
app.use(session({
    secret: 'secret',
    saveUninitialized: true,
    resave: true
}));

// passport init
app.use(passport.initialize());
app.use(passport.session());

// Global Vars
app.use(function (req, res, next) {
    res.local.success_msg = req.flash('success_msg');
    res.local.error_msg = req.flash('error_msg');
    res.local.error = req.flash('error');
    next();
});

// set Port
app.set('port', (process.env.PORT || 3000));
app.listen(app.get('port'), function () {
    console.log('Server started on port ' + app.get('port'));
});

Answer 1

根据 the documentation，更改为：

app.use(flash);

对此：

app.use(flash());

并且，将您的 app.use(flash()) 移动到您的其他路由定义之前，但在您的会话定义之后。

Answer 2

您使用 app.use() 设置的中间件按照声明的顺序执行，因此在您的情况下，将在会话处理之前调用闪存模块。快速查看 connect-flash-docs 发现 app.use(flash()); 应该在设置其他与会话相关的中间件后调用，因此请尝试将其向下移动一些行，这应该可以解决您的问题。

引自 connect-flash-docs：

Flash messages are stored in the session. First, setup sessions as usual by enabling cookieParser and session middleware. Then, use flash middleware provided by connect-flash.

req.flash 不是函数 Nodejs

req.flash is not a function Nodejs

javascript

node.js

express

flash-message