Question

12

How do I make this async foreach loop work with promises?

rated 0 times [ 16] [ 4] / answers: 1 / hits: 28912 / 10 Years ago, mon, april 14, 2014, 12:00:00

I've already messed around with Promises in it, but I'm new to them and I just can't figure out how to do it properly. At the moment, there's no point to the Promise, because it doesn't wait till the async $.get completes.

Basically, each foreach iteration has its own $.get function, and I need to have them all complete and then continue to the part that has the ...gets albumart console.log.

$.get(id,function(data) {

    //(there's some code here)

    var getZippyUrls = new Promise(function(resolve) {

            zippyarray.forEach(function(zippy) {

            //(more code)

            $.get(zippy.full, function(data) {

                //^This is the foreach of $.gets

               //(code's here)

            });  

           resolve(zippyarray);

        });

    });



    //This is my failed Promise ->

    getZippyUrls.then(function(response) {

        console.log(WE'RE OUT  + response.length);

        response.foreach(function(d) {

            console.log(Promise+d.media);

        });

        console.log('eyyyyyy');

    });



    console.log(...gets albumart);

    //Now after the previous stuff is done, move on

Answers

Only authorized users can answer the question. Please sign in first, or register a free account.

eanskylerg

Add To Favorites

Follow

Total Points: 524

Total Questions: 107

Total Answers: 100

Location: Colombia

Member since Mon, May 2, 2022

2 Years ago

eanskylerg questions

1 React Router v6 : How to render multiple component inside and outside a div with the same path

Sat, Feb 19, 22, 00:00, 2 Years ago

1 dotenv: command not found in nestjs project

Sat, Oct 30, 21, 00:00, 3 Years ago

1 How can I resolve the TypeScript Compiler error Namespace 'NodeJS' has no exported member 'Global'?

Mon, Jul 5, 21, 00:00, 3 Years ago

1 Limit x-axis in Apexcharts.js

Wed, Mar 10, 21, 00:00, 3 Years ago

1 Cannot use import statement outside a module in Vuejs. Template Django

Sat, Jan 23, 21, 00:00, 3 Years ago

View All

answered 10 Years ago anyssaarielles · Accepted Answer

In synchronous code, continuation is performed when the line ends ;

With promises, continuation is performed via .then. You were using a promise constructor and resolved it immediately, you did not wait for any task at all. I'd map my work into tasks and then either chain them with then or await them serially.

//I'm assuming

zippyarray; // array of Zippy objects



var tasks = zippyarray.map(function(zippy,i){

    return function(){ // return a task on that zippy;

       // basic logic here

       return $.get({

            // ajax request

       }).then(function(data){

            // process data like in your code

            // possibly store later for later use too

            return process(data); // return the processed data;

       });

    }

});

Now we can execute them all sequentially:

 var p = tasks[0](); // start the first one

 for(var i = 1; i < tasks.length; i++) p = p.then(tasks[i]);

 p.then(function(result){

       // all available here

 });

Or better, serially:

$.when.apply(tasks.forEach(function(t){ return t(); })).then(function(results){

     // all done

})