Loading gif while backend script is executed - django

Question

So I've got a form and when I submit it, a backend script.py is executed in Django.
It makes some statistical analysis which takes about 8 secs and when it finishes I get redirected to a next page.
So I've been trying to find a way to implement a loading gif while the script is executed but I failed in every one of my efforts.
I was thinking about using AJAX and javascript onclick method (or even onsubmit),
but they didn't work.
Thank you all in advance.

Answer 1

I found this article in StackOverflow linked to a js code. Basically in this code, he is checking for if the body has something loaded in it. If it doesn't then he shows a loading page, maybe this will help.
Here is the links
Show loading image after click button and page load
function onReady(callback) {
var intervalID = window.setInterval(checkReady, 1000);
function checkReady() {
if (document.getElementsByTagName('body')[0] !== undefined) {
console.log(document.getElementsByTagName('body')[0]);
window.clearInterval(intervalID);
callback.call(this);
}
}
}
function show(id, value) {
document.getElementById(id).style.display = value ? 'block' : 'none';
}
onReady(function () {
show('page', true);
show('loading', false);
});
body {
background: #FFF url("http://i.imgur.com/KheAuef.png") top left repeat-x;
font-family:"Brush Script MT", cursive;
}
h1 {
font-size: 2em;
margin-bottom: 0.2em;
padding-bottom: 0;
}
p {
font-size: 1.5em;
margin-top: 0;
padding-top: 0;
}
#page {
display: none;
}
#loading {
display: block;
position: absolute;
top: 0;
left: 0;
z-index: 100;
width: 100vw;
height: 100vh;
background-color: rgba(192, 192, 192, 0.5);
background-image: url("http://i.stack.imgur.com/MnyxU.gif");
background-repeat: no-repeat;
background-position: center;
}
<div id="page">
<h1>The standard Lorem Ipsum passage</h1>
<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum.</p>
</div>
<div id="loading"></div>