javascript - Node.js and asynchronous programming with Q -

is following correct way go things? sign controller action. im creating user , group add user to. notice have method level variables called user , group. rest of code asynchronous using q module.

is ok have method level variables or overriden person signing @ same time?

exports.postsignup = function(req, res, next) {      var user,         group;      return q.invoke(exports, 'parseuser', req, null)         .then(function(u)         {             user = u;             return q.invoke(exports, 'postcreateuser', user).fail(function(err) { throw err; });         })         .then(function()         {             group = new group();             group.userids = [user._id];             return q.invoke(exports, 'postcreategroup', group).fail(function(err) { throw err; });         })         .then(function()         {             user.groupid = group._id;             group.userids = [ user._id ];         })         .then(function()         {             return q.ninvoke(req, 'login', user).fail(function(err) { throw err; });         })         .then(function()         {             return res.redirect('/tour');         })         .fail(function (err)         {             console.log('u:' + user);             console.log('g:' + group);             return exports.createvalidationerror(error, req, res, user);         }); }; 

is ok have method level variables or overriden person signing @ same time?

no, won't locally scoped postsignup function.

it little ugly, nesting them might better choice here:

exports.postsignup = function(req, res, next) {     return q.invoke(exports, 'parseuser', req, null).then(function(user) {         return q.invoke(exports, 'postcreateuser', user).then(function(createduser) {             var group = new group();             group.userids = [user._id];             return q.invoke(exports, 'postcreategroup', group).then(function(createdgroup) {                 user.groupid = group._id;                 group.userids = [ user._id ]; // repeat this?                  return q.ninvoke(req, 'login', user)             }).then(function(loggedinuser) {                 return res.redirect('/tour');             }).fail(function(err) {                console.log('g:' + group);                throw err;             });         }).fail(function(err) {             console.log('u:' + user);             return exports.createvalidationerror(error, req, res, user);         });     }) // .fail(function(err) {        //     … // parseuser or createvalidationerror failed        // }); }; 

do need break down different steps different functions or can have 1 async function?

you have 1 async function currently, might want break down creating user new group, , logging him in plus redirecting him /tour.