fadeIn.js

fadein.js

Element.prototype.fadeIn = function(callback) {
  var ele = this,
      opacity = ele.style.opacity = ele.style.opacity || 0.0,
      fadeInLoop = null,
      intervalTime = 10,
      opacityAmount = 0.05;
 
  ele.style.display = 'block';
 
  // If the opacity is already greater than or equal to zero then there is nothing
  // for us to do and we break out here.
  if (opacity >= 1.0) {
    return false;
  }
 
  // Loop through until we set the opacity to 1.0
  fadeInLoop = setInterval(function() {
    opacity += opacityAmount;
 
    ele.style.opacity = opacity;
    ele.style.filter = 'alpha(opacity=' + opacity * 100 + ')';
 
    if (opacity >= 1.0) {
      clearInterval(fadeInLoop);
 
      if (typeof callback !== "undefined") {
        callback();
      }
    }
  }, intervalTime);
}
/* Example
document.getElementById('some-id').fadeIn(function() {
  console.log('Faded in the element.');
}
*/