JSFiddle - React, Tailwind, and code Playground

HTML

<div id="button">Click to load</div>

<iframe></iframe>

<div id='loading'>Page is loading...</div>

CSS

#button {
    background: blue;
    color: white;
    padding: 10px;
    width: 100px;
}
#loading {
    width: 300px;
    padding: 20px;
    background: orange;
    color: white;
    text-align: center;
    margin: 0 auto;
    display: none;
}

JavaScript

$('iframe').load(function() {
    $('#loading').hide();
});

$('#button').click(function() {
    $('#loading').show();
    $('iframe').attr( "src", "http://www.apple.com/");
});