Integralist

The BBC has a server-side image service which provides developers with multiple sized versions of any image they request. It works in a similar fashion to http://placehold.it/ but it also handles the image ratios returned (where as placehold.it doesn't).

The original BBC News process (and my re-working of the script) follows roughly these steps...

• Create new instance of ImageEnhancer
• Change any divs within the page (which have a class of delayed-image-load) into a transparent GIF using a Base64 encoded string.
  • We set the width & height HTML attributes of the image to the required size
  • We know what size the image needs to be because each div has custom data-attr set server-side to the size of the image
  • We then set a class of image-replace onto each newly created transparent image
• We use a 250ms setTimeout to unblock the UI thread and which calls a function resizeImages which enhances the image-replace images so their source is now set to a URL whe

paulirish

// http://paulirish.com/2011/requestanimationframe-for-smart-animating/
// http://my.opera.com/emoller/blog/2011/12/20/requestanimationframe-for-smart-er-animating

// requestAnimationFrame polyfill by Erik Möller. fixes from Paul Irish and Tino Zijdel

// MIT license

(function() {
    var lastTime = 0;
    var vendors = ['ms', 'moz', 'webkit', 'o'];