Differences

This shows you the differences between two versions of the page.

--- spec:at-rules-patterns [2011/12/06 23:37] – [Spec Text] dbaron
+++ spec:at-rules-patterns [2012/09/13 13:44] – [CSSOM] Rewrite with examples, fix an error. tabatkins
@@ Line 5: / Line 5: @@
 At-rules can generally be grouped into four categories:
-. processing instructions (like @import or @charset)
+  - processing instructions (like @import or @charset)
-. rules that change the context of rules inside them (like @media or @region)
+  - rules that change the context of rules inside them (like @media or @region)
-. rules that apply properties to things in the document other than elements (like @page or @viewport)
+  - rules that apply properties to things in the document other than elements (like @page or @viewport)
-. rules that define values which are too complex to define inline (like @font-face or @keyframes)
+  - rules that define values which are too complex to define inline (like @font-face or @keyframes)
 ===== Spec Text =====
@@ Line 33: / Line 33: @@
 ===== CSSOM =====
-All new at-rules need to add a few things to the CSSOM: a new constant (coordinated at the [[CSSOM Constants]] page) and a new interface that inherits from CSSRule.
+When creating a new at-rule, you need to add some CSSOM stuff as well:
-For category 1 rules, the interface should have attributes exposing all of the information they contain, like [[http://dev.w3.org/csswg/cssom/#css-import-rule|the @import rule]].
+**A new constant** (coordinated at the [[CSSOM Constants]] page), added to the CSSRule interface like:
-For category 2 rules, the interface should expose a ''cssRules'' or ''childRules'' (which?) attribute containing the child rules, and attributes for any other information they contain, like the selector in an @region.
+    partial interface CSSRule {
+        const unsigned short FOO_RULE = [number];
+    };
-For category 3 and 4 rules, the interface should expose a ''style'' attribute containing all the descriptors, and attributes for any other information they contain, like the name of a @counter-style.
+**A new interface:**
-There is no need to define the ''cssText'', ''parentRule'', or ''parentStylesheet'' for your interface; these are defined by CSSRule.
+For category 1 rules, the interface should inherit from CSSRule, and have attributes exposing all the information they contain.  For example, here's the @import rule:
-If you don't understand how to write WebIDL for the interfaces, just ask.
+    interface CSSImportRule : CSSRule {
+        readonly attribute DOMString href;
+        readonly attribute MediaList media;
+        readonly attribute CSSStyleSheet styleSheet;
+    };
+For category 2 rules, the interface should inherit from CSSGroupingRule, and have attributes for any other information they contain.  For example, here's the @media rule:
+    interface CSSMediaRule : CSSConditionRule {
+        readonly attribute MediaList media;
+    }
+(CSSConditionRule inherits from CSSGroupingRule, so it still satisfies the above criteria.)
+For category 3 and 4 rules, the interface should expose attributes for all the descriptors, and attributes for any other information they contain, like the name of a @counter-style.  For example, here's the @counter-style rule.
+    interface CSSCounterStyleRule : CSSRule {
+        readonly attribute DOMString name;
+        readonly attribute DOMString type;
+        readonly attribute DOMString symbols;
+        readonly attribute DOMString additiveSymbols;
+        readonly attribute DOMString negative;
+        readonly attribute DOMString prefix;
+        readonly attribute DOMString suffix;
+        readonly attribute DOMString range;
+        readonly attribute DOMString fallback;
+    }
+If you don't understand how to write WebIDL for the interfaces, just ask.
 ===== Grammar =====
 TODO