Element: animationiteration event
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since December 2019.
Theanimationiteration event is fired when an iteration of aCSS Animation ends, and another one begins. This event does not occur at the same time as theanimationend event, and therefore does not occur for animations with ananimation-iteration-count of one.
Syntax
Use the event name in methods likeaddEventListener(), or set an event handler property.
addEventListener("animationiteration", (event) => { })onanimationiteration = (event) => { }Event type
AnAnimationEvent. Inherits fromEvent.
Event properties
Also inherits properties from its parentEvent.
AnimationEvent.animationNameRead onlyA string containing the value of the
animation-namethat generated the animation.AnimationEvent.elapsedTimeRead onlyA
floatgiving the amount of time the animation has been running, in seconds, when this event fired, excluding any time the animation was paused. For ananimationstartevent,elapsedTimeis0.0unless there was a negative value foranimation-delay, in which case the event will be fired withelapsedTimecontaining(-1 * delay).AnimationEvent.pseudoElementRead onlyA string, starting with
'::', containing the name of thepseudo-element the animation runs on. If the animation doesn't run on a pseudo-element but on the element, an empty string:''.
Examples
This code usesanimationiteration to keep track of the number of iterations an animation has completed:
const animated = document.querySelector(".animated");let iterationCount = 0;animated.addEventListener("animationiteration", () => { iterationCount++; console.log(`Animation iteration count: ${iterationCount}`);});The same, but using theonanimationiteration event handler property:
const animated = document.querySelector(".animated");let iterationCount = 0;animated.onanimationiteration = () => { iterationCount++; console.log(`Animation iteration count: ${iterationCount}`);};Live example
HTML
<div> <div> <p>You chose a cold night to visit our planet.</p> </div> <button type="button">Activate animation</button> <div></div></div>CSS
.container { height: 3rem;}.event-log { width: 25rem; height: 2rem; border: 1px solid black; margin: 0.2rem; padding: 0.2rem;}.animation.active { animation-duration: 2s; animation-name: slide-in; animation-iteration-count: 2;}@keyframes slide-in { from { transform: translateX(100%) scaleX(3); } to { transform: translateX(0) scaleX(1); }}JavaScript
const animation = document.querySelector("p.animation");const animationEventLog = document.querySelector( ".animation-example>.event-log",);const applyAnimation = document.querySelector( ".animation-example>button.activate",);let iterationCount = 0;animation.addEventListener("animationstart", () => { animationEventLog.textContent = `${animationEventLog.textContent}'animation started' `;});animation.addEventListener("animationiteration", () => { iterationCount++; animationEventLog.textContent = `${animationEventLog.textContent}'animation iterations: ${iterationCount}' `;});animation.addEventListener("animationend", () => { animationEventLog.textContent = `${animationEventLog.textContent}'animation ended'`; animation.classList.remove("active"); applyAnimation.textContent = "Activate animation";});animation.addEventListener("animationcancel", () => { animationEventLog.textContent = `${animationEventLog.textContent}'animation canceled'`;});applyAnimation.addEventListener("click", () => { animation.classList.toggle("active"); animationEventLog.textContent = ""; iterationCount = 0; const active = animation.classList.contains("active"); applyAnimation.textContent = active ? "Cancel animation" : "Activate animation";});Result
Specifications
| Specification |
|---|
| CSS Animations Level 1 # eventdef-globaleventhandlers-animationiteration |