Loader with python & flask

Here is one way.
When you render the template in python you could pass a variable to control the visibility of the button.

render_template('page.html', visible=True)

Then, on your page perhaps something like this (found at Hiding a button in Javascript and adapted)

<script>
var hidden = {{ visible|safe }};
function action() {
    if(hidden) {
        document.getElementById('button').style.visibility = 'hidden';
    } else {
        document.getElementById('button').style.visibility = 'visible';
    }
}

You can also change the variable with an onclick function on then page itself. Your button to call a python function could look something like this.

<input type="button" id="toggler" value="Toggler" onClick="/funcionName" />

Remember to use the @app.route("/functionName") before the python function.

Hope this is close to what you wanted.

Here are the steps to achieve this.

1. Add loading button with hidden class.

2. When you click update Product button, following things should happen.

   $(".update_button").on("click", function(e){ $(".loading_button").show(); // show loading button $(".update_button").hide(); // hide update button $.ajax({}) // send ajax request to update product, on success, hide loader and show update button });