How to show loading spinner in jQuery?

There are a couple of ways. My preferred way is to attach a function to the ajaxStart/Stop events on the element itself.

$('#loadingDiv')
    .hide()  // Hide it initially
    .ajaxStart(function() {
        $(this).show();
    })
    .ajaxStop(function() {
        $(this).hide();
    })
;

The ajaxStart/Stop functions will fire whenever you do any Ajax calls.

Update: As of jQuery 1.8, the documentation states that .ajaxStart/Stop should only be attached to document. This would transform the above snippet to:

var $loading = $('#loadingDiv').hide();
$(document)
  .ajaxStart(function () {
    $loading.show();
  })
  .ajaxStop(function () {
    $loading.hide();
  });

For jQuery I use

jQuery.ajaxSetup({
  beforeSend: function() {
     $('#loader').show();
  },
  complete: function(){
     $('#loader').hide();
  },
  success: function() {}
});

You can insert the animated image into the DOM right before the AJAX call, and do an inline function to remove it...

$("#myDiv").html('<img src="images/spinner.gif" alt="Wait" />');
$('#message').load('index.php?pg=ajaxFlashcard', null, function() {
  $("#myDiv").html('');
});

This will make sure your animation starts at the same frame on subsequent requests (if that matters). Note that old versions of IE might have difficulties with the animation.

Good luck!

$('#message').load('index.php?pg=ajaxFlashcard', null, showResponse);
showLoad();

function showResponse() {
    hideLoad();
    ...
}

http://docs.jquery.com/Ajax/load#urldatacallback

Use the loading plugin: http://plugins.jquery.com/project/loading

$.loading.onAjax({img:'loading.gif'});

$('#loading-image').html('<img src="/images/ajax-loader.gif"> Sending...');

        $.ajax({
            url:  uri,
            cache: false,
            success: function(){
                $('#loading-image').html('');           
            },

           error:   function(jqXHR, textStatus, errorThrown) {
            var text =  "Error has occured when submitting the job: "+jqXHR.status+ " Contact IT dept";
           $('#loading-image').html('<span style="color:red">'+text +'  </span>');

            }
        });

JavaScript

$.listen('click', '#captcha', function() {
    $('#captcha-block').html('<div id="loading" style="width: 70px; height: 40px; display: inline-block;" />');
    $.get("/captcha/new", null, function(data) {
        $('#captcha-block').html(data);
    }); 
    return false;
});

CSS

#loading { background: url(/image/loading.gif) no-repeat center; }

This is the best way for me:

jQuery:

$(document).ajaxStart(function() {
  $(".loading").show();
});

$(document).ajaxStop(function() {
  $(".loading").hide();
});

Coffee:

  $(document).ajaxStart ->
    $(".loading").show()

  $(document).ajaxStop ->
    $(".loading").hide()

Docs: ajaxStart, ajaxStop

My ajax code looks like this, in effect, I have just commented out async: false line and the spinner shows up.

$.ajax({
        url: "@Url.Action("MyJsonAction", "Home")",
        type: "POST",
        dataType: "json",
        data: {parameter:variable},
        //async: false, 

        error: function () {
        },

        success: function (data) {
          if (Object.keys(data).length > 0) {
          //use data 
          }
          $('#ajaxspinner').hide();
        }
      });

I am showing the spinner within a function before the ajax code:

$("#MyDropDownID").change(function () {
        $('#ajaxspinner').show();

For Html, I have used a font awesome class:

<i id="ajaxspinner" class="fas fa-spinner fa-spin fa-3x fa-fw" style="display:none"></i>

Hope it helps someone.

<script>
                $(window).on('beforeunload', function (e) {
                    $("#loader").show();
                });
                $(document).ready(function () {
                    $(window).load(function () {
                        $("#loader").hide();
                    });
                });
            </script>

<div id="loader">
                    <img src="../images/loader.png" 
                         style="width:90px;">
                </div>