CSSGroupingRule: insertRule() method

{{ APIRef("CSSOM") }}

The insertRule() method of the {{domxref("CSSGroupingRule")}} interface adds a new CSS rule to a list of CSS rules.

Syntax

insertRule(rule)
insertRule(rule, index)

Parameters

• rule
  • : A string
• index {{optional_inline}}
  • : An optional index at which to insert the rule; defaults to 0.

Return value

The index of the new rule.

Exceptions

• IndexSizeError {{domxref("DOMException")}}
  • : Thrown if index is greater than the number of child CSS rules.
• HierarchyRequestError {{domxref("DOMException")}}
  • : Thrown if rule cannot be inserted at the specified index due to some CSS constraint.
• HierarchyRequestError {{domxref("DOMException")}}
  • : Thrown if the rule is a valid statement but not a nested statement.

Examples

let myRules = document.styleSheets[0].cssRules;
myRules[0].insertRule(
  "html {background-color: blue;}",
  0,
); /* inserts a rule for the HTML element at position 0 */

Specifications

{{Specifications}}

Browser compatibility

{{Compat}}