CSSKeyframesRule: appendRule() method

{{APIRef("CSSOM") }}

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

Syntax

appendRule(rule)

Parameters

• rule
  • : A string containing a keyframe rule.

Return value

None ({{jsxref("undefined")}}).

Examples

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

After appending another rule with appendRule the cssRules property returns a {{domxref("CSSRuleList")}} containing two rules.

@keyframes slide-in {
  from {
    transform: translateX(0%);
  }
}

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

{{Specifications}}

Browser compatibility

{{Compat}}