30-seconds-of-code/snippets/pulse-loader.md

title, tags

title	tags
Pulse loader	animation, beginner

Creates a pulse effect loader animation using animation-delay property.

<div class="ripple-loader">
  <div></div>
  <div></div>
</div>

.ripple-loader {
  position: relative;
  width: 64px;
  height: 64px;
}
.ripple-loader div {
  position: absolute;
  border: 4px solid #76ff03;
  border-radius: 50%;
  animation: ripple-loader 1s ease-out infinite;
}
.ripple-loader div:nth-child(2) {
  animation-delay: -0.5s;
}
@keyframes ripple-loader {
  0% {
    top: 32px;
    left: 32px;
    width: 0;
    height: 0;
    opacity: 1;
  }
  100% {
    top: 0;
    left: 0;
    width: 64px;
    height: 64px;
    opacity: 0;
  }
}

Explanation

Note: 1rem is usually 16px.

1. @keyframes defines an animation at two points in the cycle, Start(0%), where the divs neither have width nor height and are positioned at the center & End(100%), where the divs have increased height & width but position is reset to 0.
2. The divs seem to disappear as they expand. This is achieved using opacity property, which transitions from 1 to 0 in the animation.
3. .ripple-loader is the parent container of the ripples and has a definite width and height. It uses position: relative to position child divs.
4. .ripple > div, targets the two child divs of the parent to be styled. The divs are given a border of 4px & border-radius: 50% to turn them from squares to circles.
5. animation is a shorthand property for the various animation properties: animation-name, animation-duration, animation-direction, animation-iteration-count are used.
6. nth-child(n) targets the element which is the nth child of its parent.
7. animation-delay is used on the second div, so that each element does not start the animation at the same time.

Browser support

• https://caniuse.com/#feat=css-animation