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CSSKeyframesRule: appendRule() method

The appendRule() method of the CSSKeyframeRule interface appends a CSSKeyFrameRule to the end of the rules.

Syntax

js

appendRule(rule)

Parameters

rule

A string containing a keyframe rule.

Return value

None (undefined).

Examples

The CSS includes a keyframes at-rule. This will be the first CSSRule returned by document.styleSheets[0].cssRules. myRules[0] returns a CSSKeyframesRule object. Returning the cssRules property would return a CSSRuleList containing one rule.

After appending another rule with appendRule the cssRules property returns a CSSRuleList containing two rules.

css

@keyframes slidein {
  from {
    transform: translateX(0%);
  }
}

js

let myRules = document.styleSheets[0].cssRules;
let keyframes = myRules[0]; // a CSSKeyframesRule
keyframes.appendRule("to {transform: translateX(100%);}");
console.log(keyframes.cssRules); // a CSSRuleList object with two rules

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
appendRule 411–45 12 215–21 10 2815–3112–15 9.14 414.4–45 4118–45 215–21 2814–3212–14 9.33.2 4.01.0–5.0

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https://developer.mozilla.org/en-US/docs/Web/API/CSSKeyframesRule/appendRule