node.js - Setting a function callback fram an async request -

good morning all,

i have been looking answer on boards, noob brain can't make sense of it.

i have function in models/user.js

module.exports.getuserbyusername = function(username, callback){   var retuser = new user;   sql.connect(dbconfig, function(err) {     if (err) {       console.log(err);       callback();     }      // create request object     var request = new sql.request();     request.input('ip_username', sql.nvarchar, username)      // query database , records     request.query('select * [portal_users] username = @ip_username', function(err, recordset) {       if (err) {         console.log(err);         return;       } else {          var user = new user(recordset.recordset[0].username,recordset.recordset[0].password,recordset.recordset[0].email,recordset.recordset[0].name);         user.addid(recordset.recordset[0].id);         retuser = user;        }       callback();         // send records response       //res.send(recordset);      });     });      function callback() {      sql.close();       return retuser;     };     } 

and code in routes/user.js

passport.use(new localstrategy( function(username, password, done) {  user.getuserbyusername(username, function(err, user){  if(err) throw err; if(!user){     return done(null, false, {message: 'unknown user'}); }  user.comparepassword(password, user.password, function(err, ismatch){     if(err) throw err;     if(ismatch){         return done(null, user);     } else {         return done(null, false, {message: 'invalid password'});     } }); }); })); 

i have been modifying example github uses mongodb db connection, use ms sql. function calling database , returning correct values. don't know how initiate callback can pass retuser object original function processing , logging in.

i did moment try not using callback , using standard return type of function, realised given async nature wouldn't work.

any here appreciated.

thanks

ok managed figure out using post: node.js npm mssql function returning undefined

my new code is:

module.exports.getuserbyusername = function(username, callback){     var connection =  new sql.connectionpool(dbconfig, function(err) {     if (err) {       console.log(err);       callback(err);       return     }      // create request object     var request = new sql.request(connection);     request.input('ip_username', sql.nvarchar, username)      // query database , records     request.query('select * [portal_users] username = @ip_username', function(err, recordset) {       if (err) {         console.log(err);         callback(err,recordset);         return;       } else {          var user = new user(recordset.recordset[0].username,recordset.recordset[0].password.replace(/ /g,''),recordset.recordset[0].email,recordset.recordset[0].name);         user.addid(recordset.recordset[0].id);         callback(err,user);       }       sql.close();        // send records response       //res.send(recordset);      }); }); }