CSSGroupingRule.insertRule()

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

rule

A CSSOMString

indexOptional

An optional index at which to insert the rule; defaults to 0.

The index of the new rule.

IndexSizeError DOMException

Thrown if index is greater than the number of child CSS rules.

HierarchyRequestError DOMException

Thrown if, due to constraints specified by CSS, the new rule cannot be inserted into the list at the (zero-index) index position given.

InvalidStateError DOMException

Thrown if the new rule is an @namespace at-rule, and the list of child CSS rules contains anything other than @import at-rules and @namespace at-rules.