chained promise in for loop doesn't execute properly

Question

I have chainable promises which are working fine in a single series but now i want to call this serios of chain inside for loop but it does not work as expected.

see my demo plunker and see the output in console.

below is the structure of my chaining promises . I want all publicIP which is returned by funTwo; but I want to complete funThree() and then want to get all publicIP. As I know that $q.when() makes a value in promise object.

but you can see that console.log('pA', promiseArray); executed very before and console.log('res three'); and why successHandler and finally called before that?

Here surely I am missing something , may be have to write a return; in proper place , kindly help me how to executed all function in for loop and return a data array after that for loop ends which can be retried in successHandler

 MyService.funZero()
     .then(function(response) {
        console.log(response);
        var promiseArray = [];
        for(var i = 0; i < 2 ; i++) {
            console.log('I', i);
            MyService.funOne()
           .then(MyService.funTwo)
           .then(function(res2) {
                console.log('res two', res2);
                publicIP = res2.ip;
                console.log('i', publicIP);
                promiseArray.push({'ip': publicIP});
                return MyService.funThree(publicIP);
           })
           .then(function() {
                 console.log('res three');
           })
           } // for loop ends
        console.log('pA', promiseArray);
        return $q.when(promiseArray);
      })
      .then(function(res4){
          console.log('after for loop', res4);
      })
      .then(successHandler)
      .catch(errorHandler)
      .finally(final, notify);

this is not a duplicate @Phil .. I have already read this but didn't get how to apply in angularJS. — xkeshav, Oct 25 '16 at 04:53
isnt promiseArray just an array of objects? but the name implies otherwise and you are doing a $q.when(promiseArray) — Sreekanth, Oct 25 '16 at 05:04
yes `promiseArray` is an array , I want to turn it into promise object using` $q.when` so that it can be avaibale in next `.then() `? isn't it correct way? — xkeshav, Oct 25 '16 at 05:05

score 2 · Accepted Answer · answered Oct 25 '16 at 04:57

So, I'm not sure exactly what MyService.funThree does, but you can aggregate an array via ipArray.push({'ip': publicIP}) and return that to the MyService.funThree and then the subsequent function. The issue here is there is no guarantee of order in the ipArray if that's what you're looking for. Here's the middle section of that function:

ipArray = [];
for(var i = 0; i < 2 ; i++) {
  console.log('I', i);
  var promise = MyService.funOne()
    .then(MyService.funTwo)
    .then(function(res2) {
      console.log('res two', res2);
      publicIP = res2.ip;
      console.log('i', publicIP);
      ipArray.push({'ip': publicIP});
      return ipArray;
    })
    .then(MyService.funThree)
    .then(function() {
      console.log('res three');
    });

  promiseArray.push(promise);
}
console.log('pA', promiseArray);
return $q.all(promiseArray);

Thank you for the valuable input BUT in my situation `MyService.funThree()` used data from` res2` ; so this is not possible to exceute funThree in next ` .then()` — xkeshav, Oct 25 '16 at 05:11
Then instead of returning `ipArray` here, you can return `res2` and pass it as an argument to `MyService.funThree`. — R.A. Lucas, Oct 25 '16 at 05:16

chained promise in for loop doesn't execute properly

1 Answers1