CSSGroupingRule

CSS object model css-object-model

Baseline: Widely available on the web, in every major browser since Sep 2015, and long enough to count on (since Mar 2018).

niso: Partial 55%. 123 of 221 subtests pass, by system: Linux 55%, macOS 55%. Engines: QuickJS, the engine niso's WPT run uses; Node and Porffor have no recorded run. WPT results recorded at f3b4fa8, 2026-11-10; web-features 3.45.0. WPT tests · niso's support · CSS, CSSConditionRule, CSSGroupingRule, CSSMediaRule

CSSGroupingRule is an interface in idl/cssom.webidl, inheriting CSSRule, exposed in Window. What it does is on MDN; this page says what niso has of it.

Status

The web features its members belong to, each with its Baseline status on the web and how much of the feature’s WPT suite passes in niso (see Web platform support).

Feature	On the web	In niso	Members
CSS object model	Widely available	Partial 55% 123 of 221 subtests pass	4

Members

cssRules

attribute

[SameObject] readonly attribute CSSRuleList cssRules;

int32_t niso_css_grouping_rule_get_css_rules(niso_dom* dom, niso_handle self, niso_handle* out);

insertRule()

operation

unsigned long insertRule(DOMString rule, optional unsigned long index = 0);

int32_t niso_css_grouping_rule_insert_rule(niso_dom* dom, niso_handle self, const char* rule, size_t rule_len, uint32_t index, uint32_t* out);

deleteRule()

operation

undefined deleteRule(unsigned long index);

int32_t niso_css_grouping_rule_delete_rule(niso_dom* dom, niso_handle self, uint32_t index);