javascript - How to improve this code in Node.js and Express.js avoiding callback hell -

i have method in 1 of controller. purpose of controller, print array of urls using webshot package.

this code in question:

router.post('/capture', function (req, res, next) {    //check params remove     var json = json.parse(req.body.data);    var promise = new promise(function (resolve, reject) {      var totalimages = object.keys(json).length;     var arraylisturlimages = new array(totalimages);     var counter = 0;                var completedir = dir + ''; //directory url          (var value of json) {           var url = 'http://example.com/' + id + '/' + value.anothervalue;       var folder = completedir + id + '/' + value.anothervalue + '.jpg';        //options capturing image       var options = {         renderdelay: 1000,         quality: 100,         phantomconfig:         {           'local-to-remote-url-access': 'true',           'ignore-ssl-errors': 'true'         }              };        var anothervalue = value.anothervalue;        (function (anothervalue) {            webshot(url, folder, options, function (err) {         // screenshot saved                      if (err === null) {            var urlimage = "http://example.com/images/" + id + "/" + anothervalue + ".jpg";           arraylisturlimages.push(urlimage);           counter++;           console.log("counter: " + counter);            if (counter === totalimages) {                             resolve(arraylisturlimages);           }         }         else {           reject(err);         }       });           })(anothervalue);       }       }).then(function (arrayimages) {      res.send(arrayimages);        }).catch(function (errorvale) {     res.send(null);        }); }); 

this code working without problems... better. don't know how many urls need check (this important detail because need each or similar).

i have read async package... better option move code async.parallel? can use yield in code?

thanks!

this example of code flow based on inner functions:

router.post('/capture', function (req, res, next) {     // definitions      // load image     function loadimage(value) {         var url = 'http://example.com/' + id + '/' + value.anothervalue;         var folder = completedir + id + '/' + value.anothervalue + '.jpg';          //options capturing image         var options = {             renderdelay: 1000,             quality: 100,             phantomconfig:             {                 'local-to-remote-url-access': 'true',                 'ignore-ssl-errors': 'true'             }                };          return webshotpromise(url, folder, options);     }      // load whebshot promise     function webshotpromise(url, folder, options) {         return new promise((resolve, reject) => {             webshot(url, folder, options, function (err) {                 if (err) {                     reject(err);                 }                  var urlimage = "http://example.com/images/" + id + "/" + anothervalue + ".jpg";                 resolve(urlimage);             }         });     }      // method flow     const json = json.parse(req.body.data);      // json keys , iterate on load     promise.all(         object.getownpropertynames(json).map(key => loadimage(json[key]))     )     // got list of urls     .then((list) => {         res.json(list);      }, (error) => {         console.error(error);         res.json(null);     }); });