Reducing the amount of code we generate in the compiler: We still continue

lib/polymer_element.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.
 
 library polymer.polymer_element;
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:mirrors';
 
+import 'package:mdv/mdv.dart' as mdv;
 import 'package:observe/observe.dart';
 
 import 'custom_element.dart';
 import 'observe.dart';
 import 'src/utils_observe.dart' show toCamelCase, toHyphenedName;
 
 /**
  * Registers a [PolymerElement]. This is similar to [registerCustomElement]
  * but it is designed to work with the `<element>` element and adds additional
  * features.
  */
-// TODO(sigmund): change this to take the 'localName' (recent polymer change)
-void registerPolymerElement(Element elementElement, CustomElement create()) {
-  // Creates the CustomElement and then publish attributes.
-  createElement() {
-    final CustomElement element = create();
-    // TODO(jmesserly): to simplify the DWC compiler, we always emit calls to
-    // registerPolymerElement, regardless of the base class type.
-    if (element is PolymerElement) {
-      PolymerElement pElement = element;
-      pElement._parseHostEvents(elementElement);
-      pElement._parseLocalEvents(elementElement);
-      pElement._publishAttributes(elementElement);
-    }
-    return element;
-  }
-
-  registerCustomElement(elementElement.attributes['name'], createElement);
+void registerPolymerElement(String localName, PolymerElement create()) {
+  registerCustomElement(localName, () => create().._initialize(localName));
 }
 
 /**
  * *Warning*: many features of this class are not fully implemented.
  *
  * The base class for Polymer elements. It provides convience features on top
  * of the custom elements web standard.
  *
  * Currently it supports publishing attributes via:
  *
@@ skipping 11 matching lines @@
   // This is a partial port of:
   // https://github.com/Polymer/polymer/blob/stable/src/attrs.js
   // https://github.com/Polymer/polymer/blob/stable/src/bindProperties.js
   // https://github.com/Polymer/polymer/blob/7936ff8/src/declaration/events.js
   // https://github.com/Polymer/polymer/blob/7936ff8/src/instance/events.js
   // TODO(jmesserly): we still need to port more of the functionality
 
   // TODO(sigmund): delete. The next line is only added to avoid warnings from
   // the analyzer (see http://dartbug.com/11672)
   Element get host => super.host;
+
+  /**
+   * The declaration of this polymer-element, used to extract template contents
+   * and other information.
+   */
+  static Map<String, Element> _declarations = {};
+  static Element getDeclaration(String localName) {
+    if (localName == null) return null;
+    var element = _declarations[localName];
+    if (element == null) {
+      element = document.query('polymer-element[name="$localName"]');
+      _declarations[localName] = element;
+    }
+    return element;
+  }
+
   Map<String, PathObserver> _publishedAttrs;
   Map<String, StreamSubscription> _bindings;
+  List<String> _localNames = [];

[Jennifer Messerly, 2013/07/18 23:56:04]

final?

[Siggi Cherem (dart-lang), 2013/07/19 22:52:52]

Done.

 
-  void _publishAttributes(Element elementElement) {
+  void _initialize(String localName) {
+    if (localName == null) return;
+
+    var declaration = getDeclaration(localName);
+    if (declaration == null) return;
+
+    if (declaration.attributes['extends'] != null) {
+      var base = declaration.attributes['extends'];
+      // Skip normal tags, only initialize parent custom elements.
+      if (base.contains('-')) _initialize(base);
+    }
+
+    _parseHostEvents(declaration);
+    _parseLocalEvents(declaration);
+    _publishAttributes(declaration);
+    _localNames.add(localName);
+  }
+
+  void _publishAttributes(elementElement) {
     _bindings = {};
     _publishedAttrs = {};
 
     var attrs = elementElement.attributes['attributes'];
     if (attrs != null) {
       // attributes='a b c' or attributes='a,b,c'
       for (var name in attrs.split(attrs.contains(',') ? ',' : ' ')) {
         name = name.trim();
 
         // TODO(jmesserly): PathObserver is overkill here; it helps avoid
         // "new Symbol" and other mirrors-related warnings.
         _publishedAttrs[name] = new PathObserver(this, toCamelCase(name));
       }
     }
   }
 
   void created() {
     // TODO(jmesserly): this breaks until we get some kind of type conversion.
     // _publishedAttrs.forEach((name, propObserver) {
     // var value = attributes[name];
     //   if (value != null) propObserver.value = value;
     // });
-
+    _initShadowRoot();
     _addHostListeners();
   }
 
-  // TODO(sigmund): make this private once we create the shadow root directly
-  // here in polymer element.
-  void shadowRootReady(ShadowRoot root, String elementName) {
-    _addInstanceListeners(root, elementName);
+  void _initShadowRoot() {
+    for (var localName in _localNames) {
+      var declaration = getDeclaration(localName);
+      var root = createShadowRoot(localName);
+      _addInstanceListeners(root, localName);
+
+      // TODO(jmesserly): warn if apply-author-styles was not set and we don't
+      // have Shadow DOM support? In that case, styles won't have proper

[Jennifer Messerly, 2013/07/18 23:56:04]

I think this TODO is obsolete :)

[Siggi Cherem (dart-lang), 2013/07/19 22:52:52]

Done.

+      // encapsulation.
+      if (root is ShadowRoot &&

[Jennifer Messerly, 2013/07/18 23:56:04]

root is always ShadowRoot now, right?

[Siggi Cherem (dart-lang), 2013/07/19 22:52:52]

I think so. removed.

+          declaration.attributes['apply-author-styles'] != null) {

[Jennifer Messerly, 2013/07/18 23:56:04]

does polymer have apply-author-styles?

[Siggi Cherem (dart-lang), 2013/07/19 22:52:52]

turns out they have it as a property in the prototype, but not in the html, not
sure why. To match them, I removed it from here and turned it into a property in
PolymerElement.

+        root.applyAuthorStyles = true;
+      }
+
+      var templateNode = declaration.children.firstWhere(
+          (n) => n.localName == 'template', orElse: () => null);
+      if (templateNode == null) return;
+
+      root.nodes.add(cloneTemplate(templateNode.content));
+      var syntax = templateNode.attributes['syntax'];

[Jennifer Messerly, 2013/07/18 23:56:04]

mind adding a TODO? we should treat syntax like Polymer does, which probably
means defaulting to fancy-syntax.

[Siggi Cherem (dart-lang), 2013/07/19 22:52:52]

Done.

+      mdv.bindModel(root, this,
+          syntax != null ? TemplateElement.syntax[syntax] : null);
+    }
   }
 
   void bind(String name, model, String path) {
     var propObserver = _publishedAttrs[name];
     if (propObserver != null) {
       unbind(name);
 
       _bindings[name] = new PathObserver(model, path).bindSync((value) {
         propObserver.value = value;
       });
@@ skipping 356 matching lines @@
   'onKeyMessage': MediaElement.keyMessageEvent,
   'onNeedKey': MediaElement.needKeyEvent,
   'onWebGlContextLost': CanvasElement.webGlContextLostEvent,
   'onWebGlContextRestored': CanvasElement.webGlContextRestoredEvent,
   'onPointerLockChange': Document.pointerLockChangeEvent,
   'onPointerLockError': Document.pointerLockErrorEvent,
   'onReadyStateChange': Document.readyStateChangeEvent,
   'onSelectionChange': Document.selectionChangeEvent,
   'onSecurityPolicyViolation': Document.securityPolicyViolationEvent,
 };