Type extension support in polyfill.

tools/dom/src/dart2js_CustomElementSupport.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.dom.html;
 
 _callCreated(receiver) {
   return receiver.created();
 }
 
 _makeCreatedCallbackMethod() {
   return JS('',
       '''((function(invokeCallback) {
              return function() {
                return invokeCallback(this);
              };
           })(#))''',
       convertDartClosureToJS(_callCreated, 1));
 }
 
+const _typeNameToTag = const {
+  'HTMLAnchorElement': 'a',
+  'HTMLAppletElement': 'applet',
+  'HTMLAreaElement': 'area',
+  'HTMLAudioElement': 'audio',
+  'HTMLBRElement': 'br',
+  'HTMLBaseElement': 'base',
+  'HTMLBaseFontElement': 'basefont',
+  'HTMLBodyElement': 'body',
+  'HTMLButtonElement': 'button',
+  'HTMLCanvasElement': 'canvas',
+  'HTMLDListElement': 'dl',
+  'HTMLDataListElement': 'datalist',
+  'HTMLDirectoryElement': 'dir',
+  'HTMLDivElement': 'div',
+  'HTMLEmbedElement': 'embed',
+  'HTMLFieldSetElement': 'fieldset',
+  'HTMLFontElement': 'font',
+  'HTMLFormElement': 'form',
+  'HTMLFrameElement': 'frame',
+  'HTMLFrameSetElement': 'frameset',
+  'HTMLHRElement': 'hr',
+  'HTMLHeadElement': 'head',
+  'HTMLHeadingElement': 'h1',
+  'HTMLHtmlElement': 'html',
+  'HTMLIFrameElement': 'iframe',
+  'HTMLImageElement': 'image',
+  'HTMLImageElement': 'img',
+  'HTMLInputElement': 'input',
+  'HTMLKeygenElement': 'keygen',
+  'HTMLLIElement': 'li',
+  'HTMLLabelElement': 'label',
+  'HTMLLegendElement': 'legend',
+  'HTMLLinkElement': 'link',
+  'HTMLMapElement': 'map',
+  'HTMLMarqueeElement': 'marquee',
+  'HTMLMenuElement': 'menu',
+  'HTMLMetaElement': 'meta',
+  'HTMLMeterElement': 'meter',
+  'HTMLModElement': 'del',

[Jennifer Messerly, 2013/08/29 20:57:29]

there are a few duplicate entries here. How do we disambiguate?

Maybe we should require the user to pass the tag name, like document.register
does?

[blois, 2013/08/29 21:38:41]

It's actually only the polyfill which needs this- the native versions do not.
I'm inclined to keep the list unless there are specific use-cases to
disambiguate- we can add an optional parameter to override the default detection
if necessary.

[Jennifer Messerly, 2013/08/29 22:44:27]

okay, that makes sense, but surely we need that parameter for HTMLModElement,
HTMLQuoteElement, and HTMLTableSectionElement at the very least?

seems bad to have a const map with duplicate keys :)

+  'HTMLModElement': 'ins',
+  'HTMLOListElement': 'ol',
+  'HTMLObjectElement': 'object',
+  'HTMLOptGroupElement': 'optgroup',
+  'HTMLOptionElement': 'option',
+  'HTMLOutputElement': 'output',
+  'HTMLParagraphElement': 'p',
+  'HTMLParamElement': 'param',
+  'HTMLPreElement': 'pre',
+  'HTMLProgressElement': 'progress',
+  'HTMLQuoteElement': 'blockquote',
+  'HTMLQuoteElement': 'q',
+  'HTMLScriptElement': 'script',
+  'HTMLSelectElement': 'select',
+  'HTMLShadowElement': 'shadow',
+  'HTMLSourceElement': 'source',
+  'HTMLSpanElement': 'span',
+  'HTMLStyleElement': 'style',
+  'HTMLTableCaptionElement': 'caption',
+  'HTMLTableCellElement': 'td',
+  'HTMLTableColElement': 'col',
+  'HTMLTableElement': 'table',
+  'HTMLTableRowElement': 'tr',
+  'HTMLTableSectionElement': 'tbody',
+  'HTMLTableSectionElement': 'tfoot',
+  'HTMLTableSectionElement': 'thead',
+  'HTMLTextAreaElement': 'textarea',
+  'HTMLTitleElement': 'title',
+  'HTMLTrackElement': 'track',
+  'HTMLUListElement': 'ul',
+  'HTMLVideoElement': 'video',
+};
+
 void _registerCustomElement(context, document, String tag, Type type) {
   // Function follows the same pattern as the following JavaScript code for
   // registering a custom element.
   //
   //    var proto = Object.create(HTMLElement.prototype, {
   //        createdCallback: {
   //          value: function() {
   //            window.console.log('here');
   //          }
   //        }
@@ skipping 22 matching lines @@
   JS('void', '#.createdCallback = #', properties,
       JS('=Object', '{value: #}', jsCreatedCallback));
 
   var baseProto = JS('=Object', '#.prototype', baseConstructor);
   var proto = JS('=Object', 'Object.create(#, #)', baseProto, properties);
 
   var interceptor = JS('=Object', '#.prototype', interceptorClass);
 
   setNativeSubclassDispatchRecord(proto, interceptor);
 
-  JS('void', '#.register(#, #)',
-      document, tag, JS('', '{prototype: #}', proto));
+  var options = JS('=Object', '{prototype: #}', proto);
+
+  if (baseClassName != 'HTMLElement') {
+    if (_typeNameToTag.containsKey(baseClassName)) {
+      JS('=Object', '#.extends = #', options, _typeNameToTag[baseClassName]);
+    }
+  }
+
+  JS('void', '#.register(#, #)', document, tag, options);
 }