Assigning an object of outer function from inside of inner function javascript

Question

I can't assign the value of result in the inner function . any ways to do that ? I can console log the result variable inside the function . Someone advised me to do with promises . I have no idea how to do that . I am a beginner of node and express.

router.post("/register",function(req,res){
    var firstName = req.body.firstName;
    var lastName = req.body.lastName;
var email = req.body.email;
var mobile = req.body.email;
var oauthProvider = req.body.oauthProvider;
var oauthId = req.body.oauthId;
var userType = req.body.type;
if (userType === undefined) {
    userType = 1;
}
var result = {};
result.message = "Not edited";
connection.model.query("SELECT `id` FROM `users`" + "WHERE users.email = ?",[email],function(err,rows){

    if(err !== null ) 
    { 
        result.error = err;
        result.success = false;
    } else if(rows.length >= 1){
        result.success = false;
        result.message ="User already exists" ;
    }
    else  
    {   
        connection.model.query("INSERT INTO `users`(`first_name`,`last_name`,`email`,`mobile`,`password`,`user_type`) VALUES (?,?,?,?,?,?)",[firstName,lastName,email,mobile,password,userType],function(err,res){
            if(err !== null ) 
            { 
            result.error = err;
            result.success = false;
            }else{
                var user = {
                    id : res.insertId,
                    first_name : firstName,
                    email : email
                };

                connection.model.query("INSERT INTO `users_profile`(`user_id`) VALUES (?)",[user.id],function(err,profileres){
                    if(err !== null ) 
                    { 
                    result.error = err;
                    result.success = false;
                    }else{

                        if(oauthProvider != undefined  && oauthId != undefined){
                            connection.model.query("INSERT INTO `users_oauth`(`user_id`, `provider`, `provider_uid`)  VALUES             (?,?,?)",[user.id,oauthProvider,oauthId],function(err,oauthres){
                                if(err !== null ) 
                                { 
                                result.error = err;
                                result.success = false;
                                result.message = "couldn't create oauth user";
                                }
                            });

                        }
                        var token = jwt.sign(user, SECRET, {
                          expiresIn: "15d" // expires in 15 days
                        });

                        // return the information including token as JSON
                        result.success = true;
                        result.message = 'successfully registered'; 
                        result.token = token;


                    }

                });
            }
        });

    } 

    res.setHeader('content-type','text/json'); 
    res.send(json_encode(result));


});

});

Answer 1

U should send the response inside the callback as follows:

result.success = true;
 result.message = 'successfully registered'; 
 result.token = token;
 res.setHeader('content-type','text/json'); 
 res.send(json_encode(result));

instead of sending response outside the callback.

EDIT: ok i got it.. its taking your query res, so change the code a follows:

router.post("/register",function(httpreq,httpres){

result.success = true;
     result.message = 'successfully registered'; 
     result.token = token;
     httpres.setHeader('content-type','text/json'); 
     httpres.send(json_encode(result));

EDIT: As you know node.js will execute all asychronously, so in your case you are sending the response res.send b4 the callback finished. so now in my code i sent res once the callback is finished..