Merge pull request #3022 from btholt/master

Added itemRef and itemId for complete microdata support.

docs/docs/ref-04-tags-and-attributes.md

@@ -69,7 +69,7 @@ In addition, the following non-standard attributes are supported:
 
 - `autoCapitalize autoCorrect` for Mobile Safari.
 - `property` for [Open Graph](http://ogp.me/) meta tags.
-- `itemProp itemScope itemType` for [HTML5 microdata](http://schema.org/docs/gs.html).
+- `itemProp itemScope itemType itemRef itemId` for [HTML5 microdata](http://schema.org/docs/gs.html).
 
 There is also the React-specific attribute `dangerouslySetInnerHTML` ([more here](/react/docs/special-non-dom-attributes.html)), used for directly inserting HTML strings into a component.
 

src/browser/ui/dom/HTMLDOMPropertyConfig.js

@@ -164,11 +164,16 @@ var HTMLDOMPropertyConfig = {
     // keyboard hints.
     autoCapitalize: null,
     autoCorrect: null,
-    // itemProp, itemScope, itemType are for Microdata support. See
-    // http://schema.org/docs/gs.html
+    // itemProp, itemScope, itemType, itemType, itemId are for
+    // Microdata support. See http://schema.org/docs/gs.html
     itemProp: MUST_USE_ATTRIBUTE,
     itemScope: MUST_USE_ATTRIBUTE | HAS_BOOLEAN_VALUE,
     itemType: MUST_USE_ATTRIBUTE,
+    // itemID and itemRef are for Microdata support as well but
+    // only specified in the the WHATWG spec document. See
+    // https://html.spec.whatwg.org/multipage/microdata.html#microdata-dom-api
+    itemID: MUST_USE_ATTRIBUTE,
+    itemRef: MUST_USE_ATTRIBUTE,
     // property is supported for OpenGraph in meta tags.
     property: null
   },