CODEWITHSUNDEEP
jqueryeach
DazzledKid
DazzledKid

Reputation: 396

Jquery ajax call within an each loop

I'm having a problem when using the jquery .each() and .ajax() functions together. I'm using .each() to loop through 5 elements and am performing the .ajax() call for each one. My problem is that I only want the loop to continue when a response has been received from each ajax request. Currently, all 5 elements are being looped, 5 ajax requests being made, then 5 responses being returned.

Hers's a simple example:

$(".element").each(function() {
    var id= $(this).find(('txtId').val();
    $.ajax({
       type: "POST",
       url: "/Handlers/Handler.ashx",
       data: "ID=" + id,
       success: function(xml){

         // I would like the each() loop to pause until this is hit, 
         // and some additional logic can be performed. 

       }
     });

});

Cheers.

Upvotes: 12

Views: 35151

Answers (5)

michaelthedev
michaelthedev

Reputation: 152

Although it's late, i used a work around for this I created a function to handle the ajax request by passing the element

function ajax_request(element){
    var id = element.find('.txtId').val();
    console.log(id);
    $.ajax({
        type: "POST",
        url: "/Handlers/Handler.ashx",
        data: "ID=" + id,
        success: function(xml){
            console.log(xml);
        }
     });
}

$(".element").each(function() {
    // run the ajax function for current element
    ajax_request($(this));
});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div class="element">
    <input class="txtId" value="textid1"/>
</div>
<div class="element">
    <input class="txtId" value="textid2"/>
</div>
<div class="element">
    <input class="txtId" value="textid3"/>
</div>

Hope it helps anyone doing something similar

Upvotes: 0

Arooran
Arooran

Reputation: 637

You can use the jquery deffered and promise function to check the async call is success or not. http://joseoncode.com/2011/09/26/a-walkthrough-jquery-deferred-and-promise/

Upvotes: 0

Radu
Radu

Reputation: 9

i'm happy to say there's a way... but it's a bit nasty.

If you are sure the request has to give something back, then you can remove the "tryIteration" part.

$(document).ready(function() {

        loop(".buttonsPromotion", 0);

});

function loop(elements, tryIteration) {
//HOW MANY TRIES UNTIL WE STOP CHECKING
if(tryIteration<7){

    $(elements).each(function() {            
        var actuel = $(this);
        $.ajax({
           url: "write your link here",
           data: {},
           dataType: 'json',
           async: true,
           success: function(data){
               //HERE WE KNOW THE AJAX REQUEST WENT OK
               actuel.addClass('AjaxOK');    
           },
           error:function(thrownError){
                console.log(thrownError);
                //WE MAKE ANOTHER EACH ON ALL ELEMENT THAT WENT BAD
                var elemToRetry = actuel.not('AjaxOK');
                loop(elemToRetry, ++tryIteration);
            }
         });

    });
}
}

Upvotes: 0

YonahW
YonahW

Reputation: 16520

Pekka has the correct answer. You just need to edit your script as below.

$(".element").each(function() {
    var id= $(this).find(('txtId').val();
    $.ajax({
       type: "POST",
       async: false,
       url: "/Handlers/Handler.ashx",
       data: "ID=" + id,
       success: function(xml){

       }
     });

});

Upvotes: 4

Pekka
Pekka

Reputation: 449395

You could use the async option for this to make each request synchronous (= halt script execution until each request is finished):

async By default, all requests are sent asynchronous (i.e. this is set to true by default). If you need synchronous requests, set this option to false. Cross-domain requests and dataType: "jsonp" requests do not support synchronous operation. Note that synchronous requests may temporarily lock the browser, disabling any actions while the request is active.

but, as the docs already say, this is highly discouraged, as it could freeze the browser if a request hangs or times out.

It would be better to change the architecture of your code in a way that can work with the classical callback functions if at all possible.

Upvotes: 11

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