客户端会话 nodejs / Express - 错误：无法设置未定义的属性“mydata”

Question

我正在尝试在 nodejs / Express 中使用客户端会话中间件，但出现以下错误：Cannot set property 'mydata' of undefined.

我也看过这篇文章，但找不到关于我为什么会收到错误的更多线索。 node-js-client-sessions-not-creating-req-session

var bodyParser = require('body-parser');
const express = require('express');

const app = express();
const clientSessions = require("client-sessions");

var urlencodedParser = bodyParser.urlencoded({ extended: false });
var router = express.Router();

app.use(clientSessions({
  cookieName: 'mydata', // cookie name dictates the key name added to the request object
  secret: 'longsecretkeyorwhatever', // should be a large unguessable string
  duration: 24 * 60 * 60 * 1000, // how long the session will stay valid in ms
  activeDuration: 1000 * 60 * 5 // if expiresIn < activeDuration, the session will be extended by activeDuration milliseconds
}));

/* Form POST handler */
router.post('/', urlencodedParser, function(req, res) {
    if (!req.body) return res.sendStatus(400);

    if(req.body.firstName){
        req.session_state.mydata = req.body.mydata;
    }
})

Answer 1

client-sessions 的文档说明：

cookie 名称指示添加到请求对象的键名

由于您将 firstName 设置为 cookie 名称，因此会话对象可用作 req.firstName：

req.firstName.mydata = req.body.mydata