javascript - Restart animation in CSS3: any better way than removing the element?

Question

I have a CSS3 animation that needs to be restarted on a click. It's a bar showing how much time is left. I'm using the scaleY(0) transform to create the effect.

Now I need to restart the animation by restoring the bar to scaleY(1) and let it go to scaleY(0) again. My first attempt to set scaleY(1) failed because it takes the same 15 seconds to bring it back to full length. Even if I change the duration to 0.1 second, I would need to delay or chain the assignment of scaleY(0) to let the bar replenishment complete. It feels too complicated for such a simple task.

I also found an interesting tip to restart the animation by removing the element from the document, and then re-inserting a clone of it: http://css-tricks.com/restart-css-animation/

It works, but is there a better way to restart a CSS animation? I'm using Prototype and Move.js, but I'm not restricted to them.

Answer 1

No need in timeout, use reflow to apply the change:

function reset_animation() {
  var el = document.getElementById('animated');
  el.style.animation = 'none';
  el.offsetHeight; /* trigger reflow */
  el.style.animation = null; 
}

#animated {
  position: absolute;
  width: 50px; height: 50px;
  background-color: black;
  animation: bounce 3s ease-in-out infinite;
}
@keyframes bounce {
  0% { left: 0; }
  50% { left: calc( 100% - 50px ); }
  100% { left: 0; }
}

<div id="animated"></div>
<button onclick="reset_animation()">Reset</button>