Creating a Simple Animation

The YUI Animation Utility makes adding animation effects to HTMLElements easy.

For this example, we will animate the width of the <div> element named demo.

Add a little style so that we can see the animation in action:

<style type="text/css"> #demo { background:#ccc; overflow:hidden; /* so we can animate to zero width */ width:200px; } </style>

Create the demo element and a button to run the animation:

<div id="demo">Demo</div> <button id="demo-run">run</button>

Now we create an instance of YAHOO.util.Anim, passing it the element we wish to animate, and the style attribute(s) to be animated. Each attribute requires at least a to by field, which will be used as the ending value. A from field is optional; if omitted the animation starts from its current value.

<script type="text/javascript"> var attributes = { width: { to: 0 } }; var anim = new YAHOO.util.Anim('demo', attributes); </script>

The final step is to call the animate method on our instance to start the animation. The button will be the trigger that begins the animation sequence:

<script type="text/javascript"> YAHOO.util.Event.on('demo-run', 'click', function() { anim.animate(); }); </script>

This is a basic example of the YUI Animation Utility.

Configuration for This Example

You can load the necessary JavaScript and CSS for this example from Yahoo's servers. Click here to load the YUI Dependency Configurator with all of this example's dependencies preconfigured.