Async function pass data to async function

Question

I have the following code:

//calling AsyncFunction
var coords = LocationSerivice.getLocation();
var localStores;

 setTimeout(function(){

            //works
            console.log(coords);

            //calling async function again
            localStores = LocalStoresService.getLocalStores(coords[0],coords[1]);



        }, 100);

        setTimeout(function(){

                    //doesn't work
                    console.log(localStores);



               }, 100);

What am I trying to do is to first call a Async function that returns my location. Then in order to get the data from that function I am setting timeout. With the data received I am calling second Async function. And again I am setting timeout in order to get the data from my second Async function, so here it fails. If I try to display the data with console.log() in the timeout block it says undefined while console.log()in the first timeout block works.

I have tried also increasing the timeout time but it just doesn't work. Any suggestions how to get over that ?

You need to correctly pass callbacks. See http://blog.slaks.net/2015-01-04/async-method-patterns/ — SLaks, Sep 06 '15 at 01:45
One of your tags is angularjs so I'd suggest you look into `promise`s http://stackoverflow.com/questions/15604196/promises-in-angularjs-and-where-to-use-them — Jan, Sep 06 '15 at 02:02

score 0 · Answer 1 · answered Sep 06 '15 at 01:54

0

You could modify your LocalStoresService.getLocalStores method to accept a callback.

function getLocalStores (arg1, arg2, cb) {
    // do stuff.
    var localStores = 'w/e';
    if (typeof cb === 'function') return cb(localStores);
}

So your invoking method would look like this:

var coords = LocationService.getLocation();

LocalStoresService.getLocalStores(coords[0], coords[1], function (localStores) {
    console.log(localStores); // 'w/e'
});

It really depends on the type of technology you're using, as the "correct" implementation of async methods can vary from type to type (AngularJS, NodeJS, vanilla JS etc..)

answered Sep 06 '15 at 01:54

Davion

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2

One of the tags on the question is angularjs, so I think a promise is the way to go – Jan Sep 06 '15 at 02:03
I completely agree, Angular is at Ionic's core, so there's no argue there. I gave an example for vanilla JS as it seems to me he's at beginner's level. – Davion Sep 06 '15 at 02:06
Wonderful ! Promises sloved my problem :) – radioaktiv Sep 06 '15 at 03:35

score 0 · Answer 2 · answered Sep 06 '15 at 03:33

As i understand your project might be using angularjs i am giving example based on that ,

.factory('LocationSerivice', function ($http) {

return{

     getLocation : function () {
       return  $http.get('location_api');
     };

     getLocalStores : function(coords){
       return $http.get('your_local_store_api');
     };

  }
 });

Now call your API's

LocationService.getLocation().success(function(coords){
       LocationService.getLocalStores(coords).success(function(localStores){
           console.log(localStores);
       });
});

Async function pass data to async function

2 Answers2