Javascript - loading/busy indicator or transparent div over page on event click

Question

i got a client side javascript function which is triggered on a button click (basically, its a calculator!!). Sometimes, due to enormous data on the page, the javascript cal

Answer 1

Javacript to show a curtain:

function CalculateAmountOnClick () {
  var curtain = document.body.appendChild( document.createElement('div') );
  curtain.id = "curtain";
  curtain.onkeypress = curtain.onclick = function(){ return false; }
  try {
    // your operations
  }
  finally {
    curtain.parentNode.removeChild( curtain );
  }
}

Your CSS:

#curtain {
  position: fixed;
  _position: absolute;
  z-index: 99;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  _height: expression(document.body.offsetHeight + "px");
  background: url(curtain.png);
  _background: url(curtain.gif);
}

(Move MSIE 6 underscore hacks to conditionally included files as desired.)

You could set this up as add/remove functions for the curtain, or as a wrapper:

function modalProcess( callback ) {
  var ret;
  var curtain = document.body.appendChild( document.createElement('div') );
  curtain.id = "curtain";
  curtain.onkeypress = curtain.onclick = function(){ return false; }
  try {
    ret = callback();
  }
  finally {
    curtain.parentNode.removeChild( curtain );
  }
  return ret;
}

Which you could then call like this:

var result = modalProcess(function(){
  // your operations here
});