Firefox tab loading spinner runs forever if I load a image asynchronously

Question

So I get the image url in my database, get the data via AJAX and load the image like this: (Updated to show all steps)

//GET urls from server
$.get("/homeBanners", null, function(data){
        $.each(data, function(i, banner){
          console.log(i); 
          generateSlide(banner, i);
        });

});

//Generate a slide for loaded URL
function generateSlide(banner, index){
   var li = $('<li>').attr('data-target', '#slideCarousel').attr('data-slide-to', index);
   var div = $('<div>').attr('class', 'item');
   if(index == 0){
     li.addClass('active');
     div.addClass('active')
   }
   li.appendTo('.carousel-indicators');
   div.appendTo('.carousel-inner');

   var img = $('<img />').attr('src', banner.image_url).on('load', function() {
        if (!this.complete || typeof this.naturalWidth == "undefined" || this.naturalWidth == 0) {
            alert('broken image!');
        } else {
            //div.append(img);
            img.appendTo(div);
            //$('#slideCarousel').before('<div id="nav"></div>').carousel().removeClass('hidden');
            $('#slideCarousel').carousel().removeClass('hidden');
        }
    });

 }

The code runs fine, the image appears fine. But in firefox the tab loading spinner never stops. In chrome that problem doesn't happen.

If I comment the append line:

//img.appendTo(div);

or the Bootstrap Carousel line:

> //$('#slideCarousel').before('<div id="nav">').carousel().removeClass('hidden');

the spinner stops. So I really don't know why this is happening. I appreciate any help.

UPDATE:

It happens in the first time when there is no cache. I'm using Firefox 17.

The Carousel HTML:

<div id="slideshow">
               <div class="container_12"><div id="nav"></div>
                 <div id="slideCarousel" class="grid_12 carousel slide hidden">
                   <ol class="carousel-indicators">
                      <!-- AJAX -->
                   </ol>
                   <!-- Carousel items -->
                   <div class="carousel-inner">
                     <!-- AJAX -->
                   </div>
                   <!-- Carousel nav -->
                   <a class="carousel-control left" href="#slideCarousel" data-slide="prev">&lsaquo;</a>
                   <a class="carousel-control right" href="#slideCarousel" data-slide="next">&rsaquo;</a>
                </div>

              </div> 
           </div>

Answer 1

After some testing, it seems that the .on() event is the culprit. Using the accepted answer from this question, do the following:

//Generate a slide for loaded URL
function generateSlide(banner, index){
   var li = $('<li>').attr('data-target', '#slideCarousel').attr('data-slide-to', index);
   var div = $('<div>').attr('class', 'item');
   if(index == 0){
     li.addClass('active');
     div.addClass('active')
   }
   li.appendTo('.carousel-indicators');
   div.appendTo('.carousel-inner');
   $('<img/>').error(function() { alert('broken image!'); })
              .attr('src', banner.image_url)
              .appendTo(div);
   //$('#slideCarousel').before('<div id="nav"></div>').carousel().removeClass('hidden');
   $('#slideCarousel').carousel().removeClass('hidden');
 }

I have also provided a demo showing a broken image: http://jsfiddle.net/dirtyd77/SLGdE/28/

Answer 2

You are using WEBrick, the problem may be there given it's not prepared to be used on a production, you should try adding 'thin' to the Gemfile.