JavaScript Loading Screen while page loads

Question

This is a little hard to explain, So I\'ll try my best

So while a HTML page loads, I\'d like there to be a cool loading screen going on. When it finishes loading, I

Answer 1

You can wait until the body is ready:

function onReady(callback) {
  var intervalId = window.setInterval(function() {
    if (document.getElementsByTagName('body')[0] !== undefined) {
      window.clearInterval(intervalId);
      callback.call(this);
    }
  }, 1000);
}

function setVisible(selector, visible) {
  document.querySelector(selector).style.display = visible ? 'block' : 'none';
}

onReady(function() {
  setVisible('.page', true);
  setVisible('#loading', false);
});

body {
  background: #FFF url("https://i.imgur.com/KheAuef.png") top left repeat-x;
  font-family: 'Alex Brush', cursive !important;
}

.page    { display: none; padding: 0 0.5em; }
.page h1 { font-size: 2em; line-height: 1em; margin-top: 1.1em; font-weight: bold; }
.page p  { font-size: 1.5em; line-height: 1.275em; margin-top: 0.15em; }

#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("https://i.stack.imgur.com/MnyxU.gif");
  background-repeat: no-repeat;
  background-position: center;
}

  
The standard Lorem Ipsum passage
  
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.

Here is a JSFiddle that demonstrates this technique.