I'm using a bootstrap pseudo-button (a link that looks like a button). It links to a page using PHP that downloads the file (the user is never shown the linking page). When the link is clicked I want it to be replaced with something to indicate progress is happening (for instance a spinning loader) as the download takes a long time to actually begin.
How would I go about doing this?
Here is my button code
<a class="btn btn-primary btn-large " href="?key=<?php echo $key = $_GET['key'];?>&download=true"><i class="icon-cloud-download"></i> Download</a>