[css-nesting-1] Drop the CSSNestRule interface, add an issue about whether it goes on CSSStyleRule or CSSStyleDeclaration. w3c#7831

Author: tabatkins

css-nesting-1/Overview.bs

@@ -14,6 +14,7 @@ Abstract: This module introduces the ability to nest one style rule inside anoth
 
 <pre class=link-defaults>
 spec:css-color-4; type:property; text:color
+spec:css-values-4; type:dfn; text:identifier
 spec:cssom-1; type:dfn;
 	text:child css rules
 	text:specified order
@@ -497,7 +498,7 @@ Syntax {#syntax}
 Nesting Conditional Rules {#conditionals}
 -----------------------------------------
 
-	In addition to ''@nest'' rules and [=directly nested=] style rules,
+	In addition to [=nested style rules=],
 	this specification allows <dfn export>nested conditional group rules</dfn>
 	inside of [=style rules=].
 
@@ -509,7 +510,6 @@ Nesting Conditional Rules {#conditionals}
 		applying to the same elements as the parent rule
 		(when the [=conditional group rule=] matches)
 	* [=Style rules=] are [=nested style rules=],
-		and so must have [=nest-prefixed=] selectors,
 		with their [=nesting selector=] taking its definition
 		from the nearest ancestor [=style rule=].
 
@@ -915,84 +915,21 @@ into the [=CSSRule/child CSS rules=] at <var>index</var>.
 The <dfn method for=CSSStyleRule>deleteRule(<var>index</var>)</dfn> method
 must [=remove a CSS rule=] from the [=CSSRule/child CSS rules=] at <var>index</var>.
 
+Note: Serialization of {{CSSStyleRule}} with nested rules
+are already well-defined by [[CSSOM]],
+via [=serialize a CSS rule=].
 
-The {{CSSNestingRule}} Interface {#cssom-nesting}
--------------------------------------------------
+<div class=issue>
+	Whether we attach .cssRules to CSSStyleRule,
+	as described here,
+	or to CSSStyleDeclaration
+	(to be consistent with future work
+	allowing `style` attributes to have nested rules)
+	is still an open question.
 
-The {{CSSNestingRule}} interfaces represents a ''@nest'' rule:
+	Also, attaching it to .style
+	means existing code setting <code>rule.style=""</code>
+	and expecting
 
-<pre class=idl>
-[Exposed=Window]
-interface CSSNestingRule : CSSRule {
-	attribute CSSOMString selectorText;
-	[SameObject, PutForwards=cssText] readonly attribute CSSStyleDeclaration style;
-	[SameObject] readonly attribute CSSRuleList cssRules;
-	unsigned long insertRule(CSSOMString rule, optional unsigned long index = 0);
-	undefined deleteRule(unsigned long index);
-};
-</pre>
-
-The <dfn attribute for=CSSNestingRule>selectorText</dfn> attribute,
-on getting,
-must return the result of [=serialize a group of selectors|serializing=]
-the associated [=selector list=].
-On setting the {{CSSStyleRule/selectorText}} attribute these steps must be run:
-
-1. Run the <a>parse a group of selectors</a> algorithm on the given value.
-2. If the algorithm returns a non-null value replace the associated [=selector list=] with the returned value.
-3. Otherwise, if the algorithm returns a null value, do nothing.
-
-The <dfn attribute for=CSSNestingRule>style</dfn> attribute
-must return a {{CSSStyleDeclaration}} object for the style rule,
-with the following properties:
-
-<dl>
-	: [=CSSStyleDeclaration/computed flag=]
-	:: Unset.
-	: [=CSSStyleDeclaration/declarations=]
-	:: The declared declarations in the rule, in <a>specified order</a>.
-	: [=CSSStyleDeclaration/parent CSS rule=]
-	:: The [=this=] object.
-	: [=CSSStyleDeclaration/owner node=]
-	:: Null.
-</dl>
-
-The <dfn attribute for=CSSNestingRule>cssRules</dfn> attribute
-must return a {{CSSRuleList}} object for the [=CSSRule/child CSS rules=].
-
-The <dfn method for=CSSNestingRule>insertRule(<var>rule</var>, <var>index</var>)</dfn> method
-must return the result of
-invoking [=insert a CSS rule=] <var>rule</var>
-into the [=CSSRule/child CSS rules=] at <var>index</var>.
-
-The <dfn method for=CSSNestingRule>deleteRule(<var>index</var>)</dfn> method
-must [=remove a CSS rule=] from the [=CSSRule/child CSS rules=] at <var>index</var>.
-
-To serialize a {{CSSNestingRule}}:
-return the result of the following steps:
-
-<ol>
-	<li>Let |s| initially be the string "<code>@nest</code>" followed by a single SPACE (U+0020).
-	<li>Append to |s| the result of performing <a>serialize a group of selectors</a> on the rule's associated selectors,
-		followed by the string "<code> {</code>", i.e., a single SPACE (U+0020), followed by LEFT CURLY BRACKET (U+007B).
-	<li>Let |decls| be the result of performing <a>serialize a CSS declaration block</a> on the rule's associated declarations, or null if there are no such declarations.
-	<li>Let |rules| be the result of performing [=serialize a CSS rule=] on each rule in the rule's {{CSSStyleRule/cssRules}} list, or null if there are no such rules.
-	<li>If |decls| and |rules| are both null, append " }" to |s| (i.e. a single SPACE (U+0020) followed by RIGHT CURLY BRACKET (U+007D)) and return |s|.
-	<li>If |rules| is null:
-		<ol>
-			<li>Append a single SPACE (U+0020) to |s|
-			<li>Append |decls| to |s|
-			<li>Append " }" to |s| (i.e. a single SPACE (U+0020) followed by RIGHT CURLY BRACKET (U+007D)).
-			<li>Return |s|.
-		</ol>
-	<li>Otherwise:
-		<ol>
-			<li>If |decls| is not null, prepend it to |rules|.
-			<li>For each |rule| in |rules|:
-				<ol>
-					<li>Append a newline followed by two spaces to |s|.
-					<li>Append |rule| to |s|.
-				</ol>
-			<li>Append a newline followed by RIGHT CURLY BRACKET (U+007D) to |s|.
-			<li>Return |s|.
-</ol>
+	(<a href="https://github.com/w3c/csswg-drafts/issues/7850">Issue 7850</a>)
+</div>