javascript - 为什么 req.somevariable 和 res.locals 不能与 jwt 回调一起使用？

Question

我们有一个路由和一个中间件，如下所示:

当我们这样做时:

//middleware
router.use((req, res, next) => {

    // check header or url parameters or post parameters for token
    let token = req.body.token || req.query.token || req.headers['x-access-token'],


        // verifies secret and checks exp
        jwt.verify(token, config.secret, (err, decoded) => {
            if (err) {
                return res.json({
                    success: false,
                    message: 'Failed to authenticate token.'
                });
            } else {
                // if everything is good, save to request for use in other routes
                res.locals.test = "test";
                req.somevariable = "variable1";

                console.log("res.locals.test inside middleware ", JSON.stringify(res.locals.test));
                console.log("req.somevariable inside middleware ", JSON.stringify(req.somevariable));

                next();

            }
        });

    next();
});

//TestRoute
router.get('/TestRoute', (req, res) => {

    console.log("res.locals.test outside middleware ", JSON.stringify(res.locals.test));
    console.log("req.somevariable outside middleware ", JSON.stringify(req.somevariable));

});

req.somevariable 和 res.locals.test 的值在 middleware 外部是未定义

当我们这样做时:

//middleware
router.use((req, res, next) => {

    res.locals.test = "test";
    req.somevariable = "variable1";

    console.log("res.locals.test inside middleware ", JSON.stringify(res.locals.test));
    console.log("req.somevariable inside middleware ", JSON.stringify(req.somevariable));

    next();

});

//TestRoute
router.get('/TestRoute', (req, res) => {

    console.log("res.locals.test outside middleware ", JSON.stringify(res.locals.test));
    console.log("req.somevariable outside middleware ", JSON.stringify(req.somevariable));


});

req.somevariable 和 res.locals.test 的值在middleware 外部可用。

这里有什么问题吗？

Answer 1

res.locals.VARIABLENAME = req.user

当您使用 .ejs 或使用该变量进行动态渲染时，

VARIABLENAME(无论您将其设置为什么变量)都可能显示为未定义，您可能会收到类似以下错误变量名未定义。

这对于 res.locals 来说是一个奇怪的现象:当您想在渲染中使用设置为 res.locals 的变量名称时，您必须定义 req.user 在渲染文件的函数中!

后端:res.locals.currentUser = req.user

//THIS FUNCTION WILL RENDER PERFECTLY LETTING ME USE currentUser in my .ejs file
 upgradeForm(req, res, next) {
    let saved = req.user;
    if(req.user){
      res.render("users/upgrade");
    } else{
      req.flash("notice", "You've successfully signed in!");
      res.redirect("/");
    }
  }

但是

//THIS FUNCTION WILL SAY currentUser is UNDEFINED IN MY .ejs file
 upgradeForm(req, res, next) {
    if(req.user){
      res.render("users/upgrade");
    } else{
      req.flash("notice", "You've successfully signed in!");
      res.redirect("/");
    }
  }

除了工作函数渲染将 req.user 设置为变量(您甚至不必使用该变量)之外，没有代码差异。我花了 9 个小时才解决这个问题，但现在你知道了!