CSS animation-fill-mode
We're always super excited to get into CSS animations because, quite frankly, they're incredibly awesome. One overlooked animation property, however, is the animation-fill-mode property. This CSS property sets the state of the end animation when the animation is not running. Here's a quick example:
@keyframes fadeIn{
0% { opacity: 0 }
100% { opacity: 1 }
}
.fadeIn {
animation-name: fadeIn;
animation-duration: 1s;
animation-fill-mode: forwards;
}
In the case of my fadeIn animation, I want the element to stay at an opacity of 1 when the animation is complete. If I don't set the value to forwards, the element would go back to an opacity of 0 after the animation runs. In most cases, you'll likely want the the value of animation-fill-mode to be forwards, so don't forget to add it!
![Convert XML to JSON with JavaScript]()
If you follow me on Twitter, you know that I've been working on a super top secret mobile application using Appcelerator Titanium. The experience has been great: using JavaScript to create easy to write, easy to test, native mobile apps has been fun. My...
![Serving Fonts from CDN]()
For maximum performance, we all know we must put our assets on CDN (another domain). Along with those assets are custom web fonts. Unfortunately custom web fonts via CDN (or any cross-domain font request) don't work in Firefox or Internet Explorer (correctly so, by spec) though...
![Save Text Size Preference Using MooTools 1.2]()
Last time posting here I taught you how to change text-size with JavaScript. The problem with using the solution I presented as Ian Lloyd pointed out:
Increase the font size, follow a link to another web page on same site and … back...
![:valid, :invalid, and :required CSS Pseudo Classes]()
Let's be honest, form validation with JavaScript can be a real bitch. On a real basic level, however, it's not that bad. HTML5 has jumped in to some extent, providing a few attributes to allow us to mark fields as required or only valid if matching...
Indeed, animation-fill-mode defaults to “none”, which means no animation style is applied when the animation starts or ends. You could expect “forwards” to be the default one, but… nope.
The other values are “backwards” and “both”. Cue to MDN page:
https://developer.mozilla.org/en-US/docs/Web/CSS/animation-fill-mode
> You could expect “forwards” to be the default one, but… nope.
This is why Max: http://www.w3.org/TR/css3-animations/
> The keyframes specify the behavior of one cycle of the animation… If a 0% or “from” keyframe is not specified, then the user agent constructs a 0% keyframe using the computed values of the properties being animated. If a 100% or “to” keyframe is not specified, then the user agent constructs a 100% keyframe using the computed values of the properties being animated.
> …by default an animation does not affect property values after the animation ends. The ‘animation-fill-mode’ property can override this behavior.
So, it is assumed that the non-animated state is the ‘default’ resting state for the animation.
This definitely helped me out a few times. I also like the “animation-direction” property, it can lead to interesting effects: http://cdpn.io/Kdslg