[css-cascade-5] Define CSSOM Layer APIs #6576

Author: mirisuzanne

css-cascade-5/Overview.bs

@@ -1863,6 +1863,67 @@ Rolling Back Cascade Layers: the ''revert-layer'' keyword</h4>
 	but not through any other [=author origin=] [=normal=] declarations.
 
 
+<h2 id="layer-apis">Layer APIs</h2>
+
+<h3 id='extensions-to-cssimportrule-interface'>
+Extensions to the <code>CSSImportRule</code> interface</h3>
+
+The <code>CSSImportRule</code> interface is extended as follows:
+
+<pre class='idl'>
+partial interface CSSImportRule {
+  readonly attribute CSSOMString layerName;
+};
+</pre>
+
+<h3 id="the-csslayerblockrule-interface">
+The <code>CSSLayerBlockRule</code> interface</h3>
+
+	The {{CSSLayerBlockRule}} interface represents
+	the ''@layer'' [[#layer-block|block rule]]:
+
+	<pre class='idl' export>
+	[Exposed=Window]
+	interface CSSLayerBlockRule : CSSGroupingRule {
+	  readonly attribute CSSOMString name;
+	};
+	</pre>
+
+	Its <dfn attribute for=CSSLayerBlockRule>name</dfn> attribute represents
+	the [=layer name=] declared by the at-rule
+	as written, with white space removed--
+	and is an empty string if the layer is anonymous.
+
+	<div class="example">
+	  <pre class='lang-css'>
+	  @layer outer {
+	    @layer foo . bar { }
+	  }
+	  </pre>
+
+	The {{CSSLayerBlockRule/name}} of the inner ''@layer'' rule
+	is “foo.bar” (and not “foo . bar” or “outer.foo.bar”).
+	</div>
+
+<h3 id="the-csslayerstatementrule-interface">
+The <code>CSSLayerStatementRule</code> interface</h3>
+
+	The {{CSSLayerStatementRule}} interface represents
+	the ''@layer'' [[#layer-empty|statement]]:
+
+	<pre class='idl' export>
+	[Exposed=Window]
+	interface CSSLayerStatementRule : CSSRule {
+	  readonly attribute FrozenArray&lt;CSSOMString> nameList;
+	};
+	</pre>
+
+	Its <dfn attribute for=CSSLayerStatementRule>nameList</dfn> attribute represents
+	the (possibly empty) list of [=layer names=] declared by the at-rule,
+	normalized following the same rule as
+	the {{CSSLayerBlockRule}}’s {{CSSLayerBlockRule/name}} attribute.
+
+
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@@ -1883,7 +1944,8 @@ Non-trivial changes since the <a href="https://www.w3.org/TR/2021/WD-css-cascade
 
 	* Added [[#value-aliasing]] section.
 		(<a href="https://github.com/w3c/csswg-drafts/issues/6193">Issue 6193</a>)
-
+	* Added [[#layer-apis]] section.
+		(<a href="https://github.com/w3c/csswg-drafts/issues/6576">Issue 6576</a>)
 
 <h3 id="changes-2021-08">
 Changes since the 29 August 2021 Working Draft</h3>