javascript - Promises in Series are not getting executed in sequence -

i have written code based on parse example provided in parse.com execute promises in series.

but, seems sequential processing not working fine.

the below code calls cloud function namely 'samplecloudfuction' multiple times in sequential order through series of promises.

after executing loop, app make call js function load remaining items (excluding processed items).

this loop make multiple calls cloud function:

var seriespromise = new parse.promise.as();   $.each(items, function (i) {                 ..                 ..                  count++;                 if (count >= 25 || (i + 1) >= selecteditemslength) {                      .. ..  //series promise: code executed in sequence being placed within  //then() existing promise                      seriespromise = seriespromise.then(function () {                         parse.cloud.run('samplecloudfuction', itemsarray, function () {                             console.log("success callback in js");                             var temppromise = parse.promise.as();                             return temppromise;                           }, function (error) {                             alert("error " + error.code + "::");                             console.log("error callback in js")                         });                     });                      count = 0;                   }             });  .. ..   seriespromise.then(function () {                 //fetch approval state of disabled button                 alert("load remaining items");              }); 

the below function called after executing loop. but, being called in before receiving callbacks earlier requests.

seriespromise.then(function () {             //fetch approval state of disabled button             alert("load remaining items");          }); 

parse.cloud.run('samplecloudfuction', itemsarray, function () {     console.log("success callback in js");     var temppromise = parse.promise.as();     return temppromise; }) 

that doesn't work. cannot return callback - value vanish.

however, the docs state

every asynchronous method in parse javascript sdk returns promise

- don't need try construct on own!

so, why sequential processing not working correctly? because requires then callback return value of next step - can asynchronous, not yet resolved promise. then, new seriespromise wait step before executing next.

yet not returning callback - then resolved seriespromise immediately undefined. return promise .run() yields:

var seriespromise = new parse.promise.as(); $.each(items, function (i) {     …     // series promise: code executed in sequence being placed within      // then() existing promise     seriespromise = seriespromise.then(function() {        return parse.cloud.run('samplecloudfuction', itemsarray); //     ^^^^^^     });     … }); seriespromise.then(function () {     //fetch approval state of disabled button     alert("load remaining items"); }, function (error) {     alert("error " + error.code + "::");     console.log("error callback in js"); });