Javascript: wait loop for jquery callback

Question

I have a ajax like as below:

$.get('/api/get-data)
.then(function (res) {
 console.log(res);
});

And i want write a loop to get data, like this:

while (true) {
 $.get('/api/lastbids/' + auctionId)
 .then(function (res) {
 console.log(res);
 });
}

I want set delay between every request, i can use setinterval but i want when get response finished, after 500ms send another request for data.

• divakar: Use promises developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/… so you can track whether you got the response or not.
• Roko C. Buljan: @divakar what is .then() in jQuery?
• skobaljic: Create a function to get /api/lastbids/, than in callback delay 500ms, than call same function again.
• divakar: @RokoC.Buljan Since he want it to be deferred, i suggested a custom promise function.

Answer 1

You could use a simple function recursion with a recurring setTimeout:

function getBidsLoop () {
 $.get('/api/lastbids/' + auctionId).then(function (res) {
 console.log(res);
 setTimeout(getBidsLoop, 500); // << Recursive call
 });
}
getBidsLoop (); // Start

• Masoud92m: i used your code, and set 1 sec delay in backend (/api/las..) but only work in first time, please check it i.imgur.com/Xvc0gG5.png
• Roko C. Buljan: @Masoud92m fixed. Sorry, my mistake

Answer 2

You can use callbacks for each request

var firstRequest = function(callback) {
 // some random endpoint for result
 $.get('https://pokeapi.co/api/v2/pokemon/1/', function(data) {
 callback(data);
 }).fail(function() {
 callback(false);
 });
 },
 secondRequest = function(callback) {
 // some random endpoint for result
 $.get('https://pokeapi.co/api/v2/pokemon/2/', function(data) {
 callback(data);
 }).fail(function() {
 callback(false);
 });
 };
// first, run first request, wait for response, then run second request. finally grab both request's responses. 
firstRequest(function(firstResult){
 if (firstResult) {
 // you can wrap the code below with setTimeout if you want
 secondRequest(function(secondResult) {
 console.log(firstResult, secondResult);
 });
 }
});