无法访问超出其作用域的信息数据: transporter.sendMail(mailOptions，function (error，info，callback){

Question

我正在尝试从(我猜) transporter.sendMail的内置返回值中获取ip地址，因为我发现内置返回值中包含ip地址。我必须以这种方式获取ip，因为正常的var ip = req.clientIp；方式只输出::1。

我花了很多时间来解决这个问题，但我做不到。然后，我在堆栈溢出上阅读了很多关于闭包的帖子，因为我的问题与此类似，但经过几天的阅读和尝试，我发现它根本就不一样。有些解决方案只能在纯闭包的情况下工作，但是当我把它移到我的用例/代码中时，它根本不起作用。

问题是信息只存在于它的作用域中(或者只存在于回调函数中)，我可以注销信息数据，但我不能将其作为变量传递出去，因此我可以在该作用域之外使用它。如果你试图在作用域之外输出信息，那么带有info数据的变量将是未定义的。

这是因为node.js将首先运行除函数之外的所有其他代码，因此如果函数没有首先读取，那么即使我将调用变量的代码放在函数之后，变量仍将是未定义的，因为信息不存在于函数之外。即使我试图在调用变量之前调用函数，并将信息传递出去，我也不能传递变量，或者至少在我调用变量之前。

router.get('/', function(req, res, next) {
    var transporter = nodemailer.createTransport({
            service: 'Gmail',
            //var info=info.response,
            auth: {
                user: 'xxxxx', // Your email id
                pass: 'xxxxx' // Your password
            }//auth
        });//transporter=nodemailer.create

      var mailOptions={
        to: 'xxxxxx',
        subject: req.body,
        //subject: "lt",
        text: "Email Test Has Passed"
      }//mailOptions

      transporter.sendMail(mailOptions, function (error, info, callback){
        if(error){
            console.log(error);
            res.json({yo: 'error'});
        }else{
            console.log('Message sent: ' + info.response);
            //console.log('info sent: ' + info);//[obj obj]
            infor=info.response;
            res.json({yo: info.response});
        };//else
      });//();//transporter.sendmail(mailoptions)

    res.render('index', { 
        title: 'laundrytake: we clean and deliver your laundry/dry cleaning',
        page:'Home',
    });//atw is a local var inside the temp index feeded from myArtwork    
});//router.get(/)

这是我尝试过的方法。我喜欢在评论中记录我所做的事情。

router.get('/', function(req, res, next) {
    var infor;
    var func;
    //var func={};
    // var p=req.ip;

    // inside middleware handler 
    // var ipMiddleware = function(req, res, next) {
    //     var clientIp = requestIp.getClientIp(req); 
    //     next();
    // };
    // ipMiddleware;

    // on localhost you'll see 127.0.0.1 if you're using IPv4  
    // or ::1, ::ffff:127.0.0.1 if you're using IPv6

    // app.use(requestIp.mw())

    // app.use(function(req, res) {
    //     var ip = req.clientIp;
    //     res.end(ip);
    // });

    // var ip;
    // if (req.headers['x-forwarded-for']) {
    //     ip = req.headers['x-forwarded-for'].split(",")[0];
    // } else if (req.connection && req.connection.remoteAddress) {
    //     ip = req.connection.remoteAddress;
    // } else {
    //     ip = req.ip;
    // }console.log("client IP is *********************" + ip);

    // var ip = req.headers['x-forwarded-for'] || req.connection.remoteAddress;
    // if (ip.substr(0, 7) == "::ffff:") {
    // ip = ip.substr(7)
    // }
    // console.log("client IP is:");
    // console.log(ip);

    var transporter = nodemailer.createTransport({
            service: 'Gmail',
            //var info=info.response,
            auth: {
                user: 'xxxxx', // Your email id
                pass: 'xxxxx' // Your password
            }//auth
        });//transporter=nodemailer.create

        // console.log("xxx");
        //var text = 'Hello world from \n\n' + req.body.name;

      var mailOptions={
        to: 'xxxxxx',
        subject: req.body,
        //subject: "lt",
        text: "Email Test Has Passed"
      }//mailOptions

      transporter.sendMail(mailOptions, function (error, info, callback){
        if(error){
            console.log(error);
            res.json({yo: 'error'});
        }else{
            console.log('Message sent: ' + info.response);
            //console.log('info sent: ' + info);//[obj obj]
            infor=info.response;
            res.json({yo: info.response});
            // app.locals.infor=info.response;
            //return(infor, //log infor dnt fix 
            //console.log("ff"));//ff printout in the end
            //callback(infor);//log infor dnt fix //log r [f sendmail]
            //return function(){return infor};//log r [f sendmail]. with info involk })(info);info undef, with 3 or () involk tran.sendM(...)not a f
            //sign(info.response);//no print out 
            // return (
            //     function(){
            //         //infor=info.response;
            //         console.log("out :");
            //     }
            // )//}
            // func=(function() { //create a new scope using a wrapper function
            // var ilocal = info.response; //capture i into a local var
            // return function() { //return the inner function
            //     console.log("My value: " + ilocal);
            //  };//return f()
            // })();//f()
        };//else
      });//();//transporter.sendmail(mailoptions)

    //function sign (ff){var xx=ff; console.log(ff);}
    // ino=transporter.sendMail();
    // ino.out;
    //ff //ff() //ff not def return(func ff(){var xx=info.res})
    var sign = function( infor ) {//no callback unhandled promise rejec warning no recipients def err 
        console.log("User: " + infor + " is saved successfully.")
    };
    var r =transporter.sendMail;//infor: [f: sendMail] undef
    //transporter.sendMail( sign );//callback(infor) nothing inside sendMail warning
    //transporter.sendMail(mailOptions, sign );//user: null is saved succ
    console.log("infor :"); 
    console.log(infor);
    console.log(r);
    //console.log(info.response);//info not def
    //func();//not a f

    res.render('index', { 
        title: 'laundrytake: we clean and deliver your laundry/dry cleaning',
        page:'Home',
    });//atw is a local var inside the temp index feeded from myArtwork    
});//router.get(/)

Answer 1

​

$( window ).load(function() {
  console.log("loaded");
  $.ajax({
    type: 'POST',//{ '"71.11.188.189"': '' }
    data: userip,//JSON.stringify(userip),//userip,//ipad
    url: '/yhu/fkip',//same err af remove sendMail from index.js /
    dataType: 'JSON' //text same print save 500 err
  }).done(function( response ) {
    console.log("ajax POST ip");//never printed 
    console.log(userip);
    if (response.msg === '') {//w/o this //POST /yhu/fkip 500(internal server err)
            console.log("res.msg null");
            }//if(response.msg)
            else {
                // If something goes wrong, alert the error message that our service returned
                alert('Error: ' + response.msg);
            }//else
  });//.done(function(response    
});//$(window).load(function

​