Passport.js -- 如何異步使用渲染電子郵件

Question

我正在使用 Sequelize/MariaDB 和 Passport.js 運行 Express 以進行用戶身份驗證。

我在注冊部分（有效）但我似乎無法呈現和返回激活電子郵件，要求他們確認他們的電子郵件。

passport.js （包含身份驗證策略）

passport.use('user-signup-email', new LocalStrategy({
    //Process/validate input, check database for existing emails, create user, add to database...

    ...
    if (newUser) {
        var token = jwt.sign( { data: newUser.id }, newUser.login_pass + "-" + newUser.account_created);
        var URLdata = { 
            id:                newUser.id,
            expiration_time:   Date.now() + 86400000,   //24 hours
            url:               token,
            email_info:        mail.createActivationEmail(req.app, newUser.login_key, newUser.user_alias, token)                        
        };

        console.log("info: " + URLdata.email_info);

        ... 
            //Store dynamic URL and email contents (in case of resending) in database with expiration time
            //And then send the email that was just rendered
    }

mail.js

exports.createActivationEmail = (app, recipientAddress, userName, url) => {
    app.render('emails/activation_email', {    
        layout: false,
        page_title: 'Please confirm your account!',
        dynamic_url: url
    }, function(err, rendered) {
        if (err) {
            console.log("Q [" + err + "]");
        }

        console.log("R " + rendered.toString());
        return {  
            from:       adminEmailAddress,
            to:         recipientAddress,
            cc:         false,
            bcc:        false,
            subject:    'Welcome to example.com ' + userName + '!',
            html:       rendered.toString(),
            text:       "TO DO" 
        };
    });
};

passport.js的最后一個console.log顯示“信息：未定義”。 但是如果我在返回之前在mail.js模塊中打印輸出，那mail.js 。

我猜這是一個異步問題？ 我將如何修復它？
在這種情況下，我對 promise 和 async-await 塊仍然有點不清楚。

在此先感謝您提供的任何幫助！

Answer 1

你誤解了回調函數。 回調是（應該，當你編寫它們時）異步： https : //nemethgergely.com/async-function-best-practices/ 如何為 Node.js 編寫異步函數

我更改了您的createActivationEmail函數。 最后一個參數現在是一個回調，當你的代碼app.redner完成時它會被調用。

 passport.use('user-signup-email', new LocalStrategy({ //Process/validate input, check database for existing emails, create user, add to database... // ... if(newUser) { var token = jwt.sign({ data: newUser.id }, newUser.login_pass + "-" + newUser.account_created); mail.createActivationEmail(req.app, newUser.login_key, newUser.user_alias, token, (err, email_info) => { var URLdata = { id: newUser.id, expiration_time: Date.now() + 86400000, //24 hours url: token, email_info }; console.log("info: " + URLdata.email_info); //... //Store dynamic URL and email contents (in case of resending) in database with expiration time //And then send the email that was just rendered }); } }));

 exports.createActivationEmail = (app, recipientAddress, userName, url, done) => { app.render('emails/activation_email', { layout: false, page_title: 'Please confirm your account!', dynamic_url: url }, function(err, rendered) { if (err) { console.log("Q [" + err + "]"); cb(err); return; } console.log("R " + rendered.toString()); done(null, { from: adminEmailAddress, to: recipientAddress, cc: false, bcc: false, subject: 'Welcome to example.com ' + userName + '!', html: rendered.toString(), text: "TO DO" }); }); };